Table of Contents

Pro-Logic Technologies Limited provides electrical power factor correction, reactive power compensation, capacitor-bank solutions, harmonic mitigation, electrical power-quality assessment, and industrial energy-efficiency services for commercial, industrial, manufacturing, mining, agricultural, institutional, and large electrical installations in South Africa.

Power factor is a critical consideration in modern electrical installations. A facility may have substantial installed electrical capacity and still experience unnecessary current flow, poor voltage performance, increased apparent-power demand, transformer loading, reduced distribution capacity, and higher electricity costs when the electrical system operates with a poor power factor. Eskom explains that low power factor increases current flow, can contribute to voltage drops, reduces distribution capacity, and on applicable tariffs can result in reactive-power charges. Eskom identifies 0.96 as a relevant nominal power-factor threshold for its applicable arrangements.

Pro-Logic Technologies Limited approaches power factor correction as an engineering exercise rather than simply installing capacitors. A properly designed system should begin with an assessment of the electrical load profile, existing power factor, kW demand, kVA demand, reactive power, transformer characteristics, motor loading, nonlinear loads, harmonics, operating schedules, and the facility's distribution architecture.

The objective is to determine how much reactive power compensation is actually required, where it should be installed, what type of correction equipment is appropriate, and whether harmonic mitigation is necessary before a capacitor bank is connected.

POWER FACTOR CORRECTION SERVICES IN SOUTH AFRICA

Power factor correction is used to improve the relationship between real power and apparent power in an electrical installation.

In an AC electrical system, three important quantities are commonly considered:

Real power (kW) – the useful power consumed by equipment.
Reactive power (kVAr) – power associated with magnetic and electric fields in inductive and capacitive equipment.
Apparent power (kVA) – the combined electrical loading represented by real and reactive power.

Power factor is generally expressed as:

Power Factor = kW ÷ kVA

When the power factor decreases, the installation requires more kVA to deliver the same amount of useful kW.

For example, a facility consuming 500 kW at a power factor of 0.80 requires approximately:

500 ÷ 0.80 = 625 kVA

If the same facility operates at 0.95 power factor:

500 ÷ 0.95 = approximately 526 kVA

The useful real power has not changed, but the apparent-power requirement has decreased substantially.

This is one reason power factor correction can release electrical capacity within an installation.

South African commercial and industrial facilities can have complex electrical loads. Manufacturing plants, shopping centres, warehouses, office buildings, hotels, hospitals, farms, mines, workshops, water-treatment facilities, pumping stations and processing plants may operate large quantities of inductive and nonlinear equipment.

Typical loads include:

Electric motors
Pumps
Compressors
Refrigeration systems
HVAC equipment
Conveyor systems
Industrial fans
Welding equipment
Transformers
Induction equipment
Lifts and escalators
Variable-frequency drives
UPS systems
Battery chargers
Industrial lighting
Data-centre equipment
Production machinery
Air compressors
Crushers
Processing equipment

Many motor-driven loads draw reactive power from the electrical network.

Without suitable compensation, the installation can carry higher current than necessary for the useful real power being consumed.

Eskom notes that poor power factor can increase facility inefficiency, operating costs and maintenance costs, while also reducing distribution capacity through increased current flow.

For businesses with significant electricity consumption, understanding power factor can therefore be an important part of electrical-energy management.

WHAT IS POOR POWER FACTOR?

A power factor close to unity indicates that the relationship between real power and apparent power is efficient from the perspective of reactive-power demand.

A low power factor means that the installation is drawing a greater amount of apparent power for the same real-power requirement.

A typical inductive load can produce a lagging power factor.

Common examples include:

Induction motors
Transformers
Pumps
Compressors
Refrigeration compressors
Fans
Blowers
Welding transformers
Certain lighting systems
Industrial machinery

For example, a heavily loaded industrial motor may operate at a lagging power factor because magnetic fields are required for its operation.

When many such loads operate simultaneously, the aggregate reactive-power demand can become significant.

Power factor correction equipment compensates for part of that reactive-power requirement locally, reducing the amount that must be supplied through upstream electrical infrastructure.

POWER FACTOR CORRECTION FOR INDUSTRIAL FACILITIES

Industrial facilities are among the most common applications for power factor correction.

A factory may have hundreds of motors operating at different times. Some motors may be lightly loaded while others are heavily loaded. Production schedules can change throughout the day, causing reactive-power demand to fluctuate.

A fixed capacitor may therefore be inappropriate for a facility with highly variable loading.

In such installations, an automatically switched capacitor bank can be used so that compensation stages are connected or disconnected according to the actual electrical requirement.

The engineering design should consider:

Maximum demand
Minimum demand
Average demand
Motor loading
Transformer size
Existing capacitor banks
Harmonic distortion
Load diversity
Production schedules
Generator operation
Solar inverter operation
UPS operation
VFD penetration
Utility supply characteristics

Eskom's power-factor guidance emphasizes correct sizing of correction equipment so that the facility receives appropriate compensation rather than excessive correction.

AUTOMATIC POWER FACTOR CORRECTION PANELS

Automatic Power Factor Correction, commonly abbreviated as APFC, uses a controller to monitor the electrical system and switch capacitor stages according to the measured reactive-power requirement.

A typical APFC panel can contain:

Power-factor controller
Capacitor stages
Capacitor-duty contactors or switching devices
Circuit protection
Busbars
Fuses or circuit breakers
Discharge resistors
Detuned reactors where required
Cooling arrangements
Monitoring instruments
Control wiring
Indication lamps
Temperature monitoring
Surge protection where required
Harmonic protection measures
Enclosure and ventilation

The controller continuously evaluates the system and determines when compensation stages should be connected or disconnected.

This is particularly useful when loads vary significantly.

For example, a manufacturing plant may operate:

Night shift: low production

Morning: several production lines start

Afternoon: maximum production

Evening: reduced production

The reactive-power requirement can therefore change throughout the day.

An automatic system can respond to these changing conditions.

CAPACITOR BANK INSTALLATION

Capacitor banks are one of the established methods used for reactive-power compensation.

However, selecting a capacitor bank should not be based simply on the size of the incoming transformer.

The required kVAr should be calculated from actual electrical measurements and the desired target power factor.

Eskom's sizing guidance explains that the required capacitor kVAr can be determined using the existing kW and power factor together with the desired corrected power factor.

A commonly used engineering relationship is:

Qc = P [tan(φ₁) − tan(φ₂)]

Where:

Qc = required reactive compensation in kVAr

P = real power in kW

φ₁ = existing power-factor angle

φ₂ = desired power-factor angle

For example, suppose a facility operates at:

500 kW

with an existing power factor of:

0.80

and the desired power factor is:

0.95

The required compensation can be calculated using the corresponding tangent values.

The final capacitor-bank rating should then be selected based on actual operating conditions, available standard capacitor steps, harmonic considerations, switching characteristics and engineering requirements.

WHY OVERSIZING A CAPACITOR BANK IS NOT GOOD ENGINEERING

More capacitors do not automatically mean a better electrical system.

Overcorrection can create undesirable operating conditions.

If the facility's reactive-power requirement is low but a large fixed capacitor bank remains connected, the system may become overcompensated.

Potential problems include:

Leading power factor
Excessive voltage
Capacitor stress
Switching problems
Resonance risk
Increased harmonic problems
Unnecessary equipment wear
Reduced capacitor life

For this reason, Pro-Logic Technologies Limited recommends measurement and engineering assessment before selecting a final capacitor-bank size.

POWER QUALITY AND HARMONICS

Modern electrical systems cannot always be treated as simple motor-and-transformer networks.

Many modern devices are nonlinear loads.

Examples include:

Variable-frequency drives
UPS systems
Solar inverters
Battery chargers
Rectifiers
Switched-mode power supplies
LED drivers
Electronic control systems
Computer equipment
Welding equipment
Industrial converters

These devices can introduce harmonic currents into the electrical system.

Harmonics are important when designing power factor correction because capacitor banks can interact with system inductance and harmonic currents.

Technical guidance from Eaton explains that capacitor installations in systems containing nonlinear loads can create or aggravate resonance conditions, potentially magnifying harmonic currents and voltages.

This means a conventional capacitor bank should not automatically be installed simply because the measured power factor is low.

The electrical engineer should first determine whether significant harmonic distortion exists.

DETUNED POWER FACTOR CORRECTION SYSTEMS

Where harmonics are present, a detuned capacitor system may be more appropriate than a conventional capacitor bank.

A detuned system incorporates reactors with capacitors to modify the resonant characteristics of the installation.

The purpose is to reduce the likelihood of harmful resonance between the capacitor bank and the electrical network.

Modern South African power-quality equipment suppliers describe detuned systems as a solution for networks containing nonlinear loads such as variable-speed drives, inverters, UPS equipment and battery chargers.

The exact reactor tuning and capacitor selection should be established through engineering analysis.

HARMONIC FILTERS FOR INDUSTRIAL POWER SYSTEMS

Power factor correction and harmonic mitigation are related but are not identical objectives.

A conventional capacitor bank primarily supplies reactive-power compensation.

A harmonic filter is designed to address harmonic currents or voltages.

In facilities with substantial nonlinear loads, a harmonic study may therefore be required.

Potential solutions include:

Detuned capacitor banks
Passive harmonic filters
Tuned filters
Active harmonic filters
Hybrid compensation systems
Reactive-power compensation systems
Combination PFC and harmonic-filter installations

A South African mining-sector study demonstrated the importance of harmonic analysis when designing reactive-power compensation. The research examined load flow, harmonic frequency scans and voltage harmonic distortion and found that switched PFC filter banks tuned to the fifth harmonic provided a viable solution in the studied mining application.

The lesson for industrial customers is straightforward: power factor correction should be designed around the complete electrical system, not around the capacitor bank alone.

POWER FACTOR CORRECTION FOR MINING OPERATIONS

South Africa's mining sector has demanding electrical loads.

Mining operations can use:

Crushers
Conveyors
Pumps
Fans
Hoists
Compressors
Mills
Drilling equipment
Processing equipment
Large motors
VFDs
Transformers
Welding systems

Large motors and nonlinear equipment can create both reactive-power and harmonic challenges.

A mining installation may therefore require:

Load-flow analysis

Power-factor analysis

Harmonic analysis

Transformer assessment

Capacitor-bank design

Protection coordination

Switching analysis

Voltage-quality assessment

A South African coal-mining case study specifically investigated PFC, load flow, harmonic frequency scans and harmonic voltage distortion, illustrating the importance of coordinated reactive-power and harmonic compensation in large nonlinear installations.

Pro-Logic Technologies Limited can approach such projects by considering the complete electrical distribution system and the actual operating characteristics of the facility.

POWER FACTOR CORRECTION FOR MANUFACTURING PLANTS

Manufacturing facilities often contain a mixture of motors, drives, heaters, control systems, conveyors, pumps, compressors and electronic equipment.

The load may change rapidly.

A production line may operate at maximum capacity for several hours and then shut down or operate at partial capacity.

This is why automatic correction is frequently more appropriate than a permanently connected fixed capacitor.

A properly engineered APFC system can use multiple capacitor steps.

For example:

Step 1: 25 kVAr
Step 2: 25 kVAr
Step 3: 50 kVAr
Step 4: 50 kVAr
Step 5: 100 kVAr
Step 6: 100 kVAr

The actual configuration would depend on the measured electrical load.

The controller can combine stages to approximate the instantaneous reactive-power requirement.

POWER FACTOR CORRECTION FOR COMMERCIAL BUILDINGS

Commercial buildings can also experience poor power factor.

Potential loads include:

Air-conditioning systems
Chillers
Pumps
Elevators
Escalators
Refrigeration
Ventilation fans
Data-centre equipment
UPS systems
Lighting systems
Mechanical plant
Fire pumps

A building with large HVAC equipment can have substantial inductive loading.

The power factor can change depending on how many chillers, pumps, compressors and air-handling systems are operating.

Power factor monitoring can therefore help identify periods of poor performance.

POWER FACTOR CORRECTION FOR HOTELS

Hotels operate continuously and often contain diverse electrical loads.

These can include:

Air conditioning
Kitchen equipment
Refrigeration
Water pumps
Laundry machines
Elevators
Lighting
HVAC fans
Water heating
Commercial refrigeration
Mechanical equipment

The electrical demand can vary considerably between daytime and nighttime.

A correctly designed automatic correction system can accommodate these changing conditions.

However, hotel electrical systems can also contain large quantities of electronic equipment, making harmonic assessment important.

POWER FACTOR CORRECTION FOR HOSPITALS

Hospitals require reliable electrical systems.

Their electrical infrastructure can include:

HVAC systems
Pumps
Medical equipment
UPS systems
Emergency systems
Ventilation
Refrigeration
Sterilisation equipment
Lifts
Lighting
Data systems

Power-quality engineering must be approached carefully in such environments.

Power factor correction equipment should be properly integrated with the facility's electrical protection, emergency supply, generator systems and critical-load architecture.

Where sensitive equipment and nonlinear loads are present, harmonic assessment is particularly important.

POWER FACTOR CORRECTION FOR SHOPPING CENTRES

Shopping centres can contain hundreds of electrical loads.

Examples include:

HVAC
Escalators
Elevators
Pumps
Refrigeration
Restaurants
Retail lighting
Signage
Security systems
Data networks
Parking systems
Tenant equipment

The combined load can create a significant reactive-power requirement.

An electrical energy assessment can identify the relationship between:

kVAr

kVA

Power factor

Maximum demand

Harmonic distortion

Voltage

Understanding these parameters allows the facility owner to determine whether power factor correction could improve the electrical installation.

POWER FACTOR CORRECTION FOR WAREHOUSES AND LOGISTICS FACILITIES

Large warehouses increasingly use automated systems.

Typical equipment includes:

Conveyor motors
Sorting systems
Automated storage systems
Refrigeration
HVAC
Battery chargers
Forklift charging systems
Pumps
Compressors
LED lighting
VFD-driven motors

Battery chargers and electronic drives can introduce nonlinear currents.

A PFC system should therefore be selected based on the complete load profile.

POWER FACTOR CORRECTION FOR COLD STORAGE FACILITIES

Cold storage facilities can have significant compressor and refrigeration loads.

Compressors are typically inductive loads and can contribute to reactive-power demand.

A cold-storage facility may have:

Multiple compressors
Condenser fans
Evaporator fans
Pumps
Refrigeration controls
Defrost equipment
Lighting
Battery chargers
HVAC equipment

The compressor loading can change depending on temperature and refrigeration demand.

Automatic correction can therefore be considered where appropriate.

POWER FACTOR CORRECTION FOR WATER AND WASTEWATER FACILITIES

Water-treatment and pumping facilities often operate many motors.

Examples include:

Borehole pumps
Booster pumps
Transfer pumps
Sewage pumps
Aeration systems
Sludge pumps
Filtration equipment

Large pumps can create significant reactive-power demand.

Variable-frequency drives may also be used for speed control.

Because VFDs are nonlinear loads, harmonic analysis should be considered before installing capacitor correction.

POWER FACTOR CORRECTION FOR AGRICULTURAL FACILITIES

Agricultural operations can use:

Irrigation pumps
Borehole pumps
Refrigeration
Grain-processing machinery
Fans
Compressors
Milking equipment
Water-treatment systems
Cold rooms

Where motors operate for long periods, power-factor improvement may help optimize the electrical installation.

POWER FACTOR CORRECTION FOR DATA CENTRES

Data centres present a different challenge.

Modern data-centre electrical systems often contain:

UPS systems
Rectifiers
Power supplies
Cooling equipment
Fans
Pumps
Battery systems
Electronic loads

Many modern power supplies have high input power factor, but the overall system still requires detailed power-quality analysis.

It is important not to install conventional capacitors blindly on a facility dominated by electronic equipment.

Harmonic measurements, UPS specifications and the overall electrical topology should be considered.

POWER FACTOR CORRECTION AND GENERATORS

Generator operation requires special consideration.

A facility that normally operates from the utility supply may behave differently when operating from standby generators.

Capacitor banks can affect generator voltage regulation and reactive-power behaviour.

Therefore, a PFC system should be evaluated under:

Utility operation

Generator operation

Parallel operation where applicable

Low-load conditions

Maximum-load conditions

Automatic capacitor switching may need to be coordinated with generator controls.

This is one reason professional engineering assessment is important before modifying a facility's reactive-power compensation system.

POWER FACTOR CORRECTION AND SOLAR SYSTEMS

Modern commercial facilities increasingly combine:

Utility supply
Solar PV
Battery energy storage
Inverters
Generators
Variable-frequency drives
UPS systems

The electrical system becomes more complex as multiple power-electronic devices interact.

A solar inverter may provide reactive-power control depending on its design and operating configuration.

Therefore, a power-factor correction strategy should consider the complete system rather than treating the utility connection in isolation.

POWER FACTOR CORRECTION AUDIT

A professional PFC project should start with an electrical assessment.

A power-factor audit may include:

1. Electrical documentation review

Review available:

Single-line diagrams
Transformer ratings
Main distribution boards
Sub-distribution boards
Existing capacitor banks
Generator ratings
Solar systems
Major motor loads
Protection systems

2. Site inspection

Inspect:

Main switchboards
Transformers
Distribution panels
Capacitor banks
Cable arrangements
Busbars
Motor control centres
VFDs
UPS systems
Generator connections

3. Electrical measurements

Measurements may include:

Voltage
Current
kW
kVAr
kVA
Power factor
Frequency
THD
Individual harmonics
Maximum demand
Load profile

4. Load-profile analysis

The data is reviewed to determine when the facility experiences its highest reactive-power requirement.

5. Equipment selection

The appropriate compensation technology is selected.

6. Installation

The selected system is installed in accordance with the applicable engineering requirements and project specifications.

7. Commissioning

The system is tested under operating conditions.

8. Performance verification

Power factor, kVA, reactive power and other relevant parameters are measured after commissioning.

WHY MEASUREMENT IS IMPORTANT

A single power-factor reading does not necessarily represent the entire electrical installation.

A facility might show:

0.82 PF at 09:00

0.91 PF at 12:00

0.97 PF at 15:00

0.86 PF at 19:00

If the system is designed from only one reading, the correction equipment could be incorrectly sized.

Longer-duration logging provides a more accurate representation of actual operation.

This is particularly important for:

Factories
Mines
Shopping centres
Hotels
Hospitals
Cold stores
Processing plants
Pumping stations
Large workshops

POWER FACTOR MONITORING

Power factor monitoring can be performed using appropriate power-quality meters and energy analysers.

Depending on the project, monitoring may capture:

Voltage
Current
Real power
Reactive power
Apparent power
Power factor
Frequency
THD
Individual harmonic orders
Demand
Maximum demand
Load profile

The information can be used to determine whether the problem is genuinely a reactive-power problem or whether other electrical-quality issues are contributing to the observed performance.

COMMON SYMPTOMS OF POOR POWER FACTOR

A facility may experience:

High kVA demand
Increased current
Voltage drop
Transformer loading
Reduced available capacity
Reactive-power charges on applicable tariffs
Electrical inefficiency
Overloaded distribution equipment
Higher losses
Difficulty accommodating new loads

However, these symptoms can have multiple causes.

For example, voltage drop may be related to conductor sizing, network impedance, transformer loading, poor connections, or other factors.

Professional diagnosis should therefore distinguish between power-factor problems and other electrical faults.

POWER FACTOR CORRECTION AND TRANSFORMERS

Transformers have finite kVA capacity.

If an installation has poor power factor, a greater portion of the transformer's available kVA is used to deliver reactive power.

Improving power factor can reduce the apparent-power requirement of the connected load and potentially release capacity.

Eskom's energy advisory material specifically notes that appropriate power-factor correction can free capacity for other uses.

This does not mean that PFC automatically increases the transformer's nameplate rating.

Instead, it can reduce the kVA burden associated with the same real-power load.

POWER FACTOR CORRECTION AND CABLE LOADING

For a given amount of real power, lower power factor generally means higher current.

Higher current can increase:

I²R losses
Voltage drop
Conductor heating
Transformer losses
Switchgear loading

Correcting reactive power locally can reduce upstream current.

However, the actual benefits depend on the installation topology and where the compensation is connected.

CENTRALIZED VERSUS DISTRIBUTED CORRECTION

Power factor correction can be implemented at different points.

Centralized correction

A capacitor bank is installed near the main distribution board or incoming supply.

Advantages can include:

Centralized control
Easier maintenance
Automatic staged correction
Suitable for facilities with multiple loads

Distributed correction

Compensation is installed near individual loads or groups of loads.

This can be appropriate where:

Large motors operate independently
Long feeder cables are involved
Individual loads have consistent operating patterns

The correct approach depends on the facility's electrical architecture.

MOTOR POWER FACTOR CORRECTION

Motors are common inductive loads.

Individual motor correction can sometimes be considered, but capacitor selection must be carefully coordinated with motor operation and switching.

The objective is not simply to connect a capacitor to every motor.

Potential considerations include:

Motor size
Motor loading
Starting method
Motor switching frequency
VFD operation
Motor speed
Existing compensation
Harmonic environment

Motor correction should be designed so that it does not create undesirable operating conditions.

POWER FACTOR CORRECTION FOR MOTOR CONTROL CENTRES

Motor Control Centres can contain many motors and drives.

An MCC may supply:

Pumps
Fans
Conveyors
Compressors
Mixers
Crushers
Production machinery

The reactive-power profile can change as motors are started and stopped.

An APFC system at an appropriate distribution point can provide dynamic compensation.

Where multiple VFDs are present, harmonic measurements are strongly relevant to the PFC design.

POWER FACTOR CORRECTION FOR VFD SYSTEMS

Variable-frequency drives provide valuable motor-speed control but are nonlinear electrical loads.

They can generate harmonic currents depending on drive topology, operating conditions and system design.

This creates an important distinction:

Low power factor does not automatically mean "install capacitors."

The electrical system should be assessed for:

Displacement power factor
True power factor
Harmonic distortion
Current waveform
Voltage waveform
VFD configuration
Existing filters
Transformer impedance

In some installations, harmonic mitigation may be more important than conventional capacitor correction.

ACTIVE HARMONIC FILTERS AND REACTIVE COMPENSATION

Active harmonic filters use power electronics to compensate selected unwanted current components.

They may be considered in facilities where:

Harmonic distortion is high
Loads are highly variable
Multiple nonlinear loads exist
Conventional capacitor banks are unsuitable
Dynamic compensation is required

An active filter can be configured according to the electrical system and required compensation objectives.

The correct technology should be determined by engineering assessment rather than by applying the same equipment to every facility.

POWER FACTOR CORRECTION AND ELECTRICITY BILL OPTIMISATION

Power factor can influence electricity costs depending on the applicable utility tariff and customer arrangement.

Eskom states that power factor affects electricity billing on certain tariffs and provides power-factor feedback as part of its energy advisory and tariff-analysis services.

Therefore, a business considering PFC should examine actual electricity bills and tariff conditions before calculating projected financial benefits.

The expected business case should consider:

Existing reactive-power charges
kVA demand
Maximum demand
Tariff structure
Correction equipment cost
Installation cost
Maintenance
Expected savings
Payback period
Future load growth

POWER FACTOR CORRECTION AND MAXIMUM DEMAND

Maximum demand is an important consideration for large electricity users.

A facility with poor power factor may draw significantly higher kVA than its real-power consumption would suggest.

Correcting the reactive component can reduce the kVA demand profile.

Eskom explicitly identifies power-factor correction as one potential method of reducing an exceeded notified maximum demand in suitable circumstances.

However, PFC should not be presented as a universal solution to maximum-demand problems. Load management, process scheduling, equipment efficiency and supply-capacity planning may also be required.

POWER FACTOR CORRECTION FOR NEW ELECTRICAL INSTALLATIONS

PFC should be considered during electrical-system design rather than only after problems occur.

For new projects, the engineering team can evaluate:

Expected load
Transformer size
Motor population
VFD population
Solar installation
Generator operation
UPS systems
Harmonic-producing loads
Future expansion
Distribution architecture

Early consideration can reduce the risk of installing inappropriate equipment later.

POWER FACTOR CORRECTION FOR EXISTING INSTALLATIONS

Existing facilities can be assessed through a retrofit study.

The process can include:

Inspection → Measurement → Analysis → Design → Installation → Commissioning → Verification

Existing capacitor banks should also be inspected.

Problems can include:

Failed capacitors
Blown fuses
Failed contactors
Faulty controllers
Reactor overheating
Poor ventilation
Loose connections
Harmonic stress
Incorrect settings
Insufficient stages
Overcompensation

Replacing individual components without identifying the root cause can result in repeated failures.

CAPACITOR BANK MAINTENANCE

Power factor correction equipment requires maintenance.

Inspection can include:

Visual inspection
Terminal inspection
Temperature checks
Capacitor condition
Contactor condition
Fuse condition
Controller operation
Reactor condition
Ventilation
Cooling fans
Harmonic measurements
Current measurements

Capacitors can degrade over time.

A capacitor bank that once corrected the installation properly may eventually provide less effective compensation because of component degradation or changes in the facility's load.

WHY CAPACITOR BANKS FAIL

Common causes can include:

Excessive temperature
Harmonic currents
Poor ventilation
Overvoltage
Incorrect capacitor selection
Excessive switching
Failed contactors
Poor connections
Aging
Resonance
Incorrect system design

Harmonic-rich environments deserve particular attention because capacitor installations can interact with harmonic currents and system impedance.

POWER FACTOR CORRECTION COMMISSIONING

Commissioning should verify that the system operates correctly under actual electrical conditions.

The commissioning process can include:

Checking connections
Verifying phase sequence
Confirming protection
Checking controller settings
Checking capacitor stages
Measuring voltage
Measuring current
Measuring kW
Measuring kVAr
Measuring kVA
Measuring power factor
Assessing harmonic levels
Confirming automatic switching
Confirming alarms

The final power factor should be verified rather than assumed.

ELECTRICAL SAFETY AND ENGINEERING COMPLIANCE

Electrical installations in South Africa are subject to applicable electrical legislation, standards, utility requirements, equipment specifications and project-specific engineering requirements.

SANS 10142-1 is an important South African low-voltage installation standard and contains provisions relating to power-factor correction in the context of electrical installation design.

The exact compliance requirements depend on the type of installation, voltage level, project scope, equipment and applicable authority requirements.

Power factor correction work should therefore be undertaken by suitably qualified and authorized electrical professionals in accordance with the applicable South African requirements.

POWER FACTOR CORRECTION DESIGN FOR THREE-PHASE SYSTEMS

Most industrial PFC applications involve three-phase electrical systems.

Important parameters include:

Line-to-line voltage
Line current
Frequency
kW
kVAr
kVA
Power factor
Transformer impedance
Short-circuit level
Harmonic distortion

The design must also consider the system's switching arrangement and protection.

For a three-phase system, real power is commonly related to voltage, current and power factor through:

P = √3 × V × I × PF

This relationship demonstrates why improving power factor can reduce current for the same real-power demand.

POWER FACTOR CORRECTION AND VOLTAGE DROP

Higher current creates higher voltage drop across electrical impedance.

If a facility draws unnecessary reactive current through long feeders, the upstream network may experience additional voltage drop.

Local reactive-power compensation can reduce the reactive component of upstream current.

However, voltage-drop problems should always be diagnosed comprehensively.

A power-factor correction project should not be used as a substitute for correcting:

Undersized cables
Poor connections
Excessive feeder length
Overloaded transformers
Poor phase balance
Faulty equipment

POWER FACTOR CORRECTION FOR LARGE ELECTRICAL MOTORS

Large motors require particular attention because their reactive-power demand can be significant.

Typical applications include:

Mining motors
Pump motors
Compressor motors
Crusher motors
Conveyor motors
Fan motors
Industrial process motors

For large motors, PFC selection should consider starting conditions and operating characteristics.

A capacitor connected at the wrong point or with inappropriate switching can create undesirable transient or resonance conditions.

POWER FACTOR CORRECTION FOR COMPRESSORS

Industrial compressors can consume significant real and reactive power.

Applications include:

Manufacturing
Refrigeration
Pneumatic systems
Mining
Food processing
Chemical processing
Workshops

Multiple compressors can operate according to pressure demand.

An automatic correction system may therefore be suitable where reactive-power demand varies.

POWER FACTOR CORRECTION FOR PUMPING SYSTEMS

Pumps are common across South Africa.

Applications include:

Water supply
Irrigation
Mining
Agriculture
Municipal systems
Wastewater
Industrial processes

Pump motors can contribute substantially to reactive-power demand.

Where VFDs are installed, harmonic analysis should be included in the electrical assessment.

POWER FACTOR CORRECTION FOR HVAC SYSTEMS

Large HVAC systems can include:

Chillers
Pumps
Fans
Compressors
Cooling towers
Air-handling units

Commercial buildings with significant HVAC loads can experience changing reactive-power demand depending on weather and occupancy.

An automatic system can respond to changing demand.

POWER FACTOR CORRECTION FOR ELECTRICAL WORKSHOPS

Workshops can contain:

Welding machines
Compressors
Lathes
Milling machines
Grinders
Pumps
Motors
Battery chargers
Lighting

Welding equipment and electronic equipment can introduce nonlinear electrical characteristics.

The appropriate PFC strategy should therefore be based on measurements.

POWER FACTOR CORRECTION FOR FOOD-PROCESSING PLANTS

Food-processing plants can use:

Motors
Conveyors
Refrigeration
Compressors
Pumps
Mixers
Packaging machines
HVAC
Heating equipment

The combination of motor loads and electronic equipment can produce a complex electrical profile.

Power-quality assessment can identify whether the facility requires:

Capacitor correction

Detuned correction

Harmonic filtering

Active filtering

or a combination of technologies.

POWER FACTOR CORRECTION FOR TEXTILE AND GARMENT FACTORIES

Textile factories can have large numbers of motors operating simultaneously.

Examples include:

Spinning machines
Weaving equipment
Sewing equipment
Compressors
Fans
Pumps
HVAC

The electrical profile can vary significantly during production.

Automatic correction can be used where appropriate.

POWER FACTOR CORRECTION FOR PRINTING PLANTS

Printing facilities can contain:

Motors
Pumps
Compressors
Dryers
Drives
Servo systems
Electronic controls
HVAC

Servo drives and electronic equipment make harmonic analysis increasingly important.

POWER FACTOR CORRECTION FOR PLASTIC AND PACKAGING INDUSTRIES

Plastic-processing facilities can have:

Extruders
Injection-moulding machines
Motors
Hydraulic systems
Heating systems
Compressors
Pumps
Cooling systems

Large motor loads combined with power electronics can create both reactive-power and harmonic challenges.

POWER FACTOR CORRECTION FOR CEMENT AND CONSTRUCTION MATERIAL PLANTS

Construction-material plants may use:

Crushers
Conveyors
Mills
Fans
Pumps
Compressors
Large motors

These systems can have substantial electrical demand.

Power-factor correction should be designed alongside the facility's load-flow and harmonic characteristics.

POWER FACTOR CORRECTION FOR STEEL AND METAL PROCESSING

Metal-processing plants may use:

Motors
Welding equipment
Furnaces
Compressors
Rolling equipment
Cranes
Drives

Such environments can present significant power-quality challenges.

A conventional capacitor bank may not be sufficient.

A detailed engineering assessment may identify the need for harmonic filters or more advanced reactive-power compensation.

POWER FACTOR CORRECTION FOR CRANES AND HOISTS

Cranes and hoists can have rapidly changing loads.

Motor acceleration, deceleration and regenerative operation can produce dynamic electrical conditions.

Where VFDs are used, harmonic and power-quality characteristics should be evaluated.

POWER FACTOR CORRECTION FOR DATA AND TELECOMMUNICATION FACILITIES

Electronic infrastructure may contain many switch-mode power supplies and UPS systems.

The design should consider:

Input power factor
Harmonic current
UPS topology
Generator compatibility
Transformer loading
Cooling equipment

PFC should not be approached solely from the perspective of traditional motor loads.

POWER FACTOR CORRECTION FOR SOLAR-INVERTER-BASED FACILITIES

Solar systems introduce power-electronic conversion into the electrical network.

A facility may experience different power-factor characteristics during:

High solar generation
Low solar generation
Night operation
Generator operation
Battery charging
Battery discharging

Therefore, the PFC strategy should consider all operating modes.

POWER FACTOR CORRECTION AND ENERGY MANAGEMENT

Power factor correction can form part of a broader energy-management strategy.

Other measures can include:

Motor efficiency improvements
Variable-speed control
Load scheduling
Peak-demand management
Efficient lighting
HVAC optimization
Transformer optimization
Solar PV
Battery storage
Compressed-air optimization
Preventive maintenance

PFC should therefore be considered one component of an overall electrical-efficiency program.

POWER FACTOR CORRECTION AND ENERGY SAVINGS

A properly designed PFC system may provide financial benefits by reducing applicable reactive-power charges and/or reducing kVA demand where the tariff structure makes those charges relevant.

However, the actual savings depend on:

Utility tariff
Existing power factor
Load profile
kW demand
kVA demand
Reactive-power charges
Maximum demand
Equipment cost
Operating hours

Savings should therefore be calculated using the customer's actual billing information.

Eskom's published guidance specifically discusses power-factor correction as a mechanism for reducing costs associated with applicable electricity charges and for improving electrical capacity utilization.

POWER FACTOR CORRECTION PAYBACK ANALYSIS

Before investment, a customer can compare:

Installation cost

against

Expected annual savings

The simple payback period can be estimated as:

Payback = Project Cost ÷ Annual Savings

For example, if a project costs R250,000 and produces estimated annual savings of R100,000:

Payback = 2.5 years

This is only a simple financial calculation.

A proper business case may also consider:

Maintenance
Equipment life
Financing
Tariff changes
Load growth
Replacement costs
Downtime
Production impact

POWER FACTOR CORRECTION FOR LARGE COMMERCIAL CUSTOMERS

Large customers should not select PFC equipment based solely on a brochure rating.

The system should be matched to the customer's:

Electrical voltage
Frequency
Load
kVAr requirement
Harmonic environment
Transformer capacity
Distribution architecture
Future expansion

A professional design can help prevent both undercorrection and overcorrection.

UNDERCORRECTION

Undercorrection occurs when insufficient reactive-power compensation is installed.

Possible consequences include:

Continued low power factor
Continued reactive-power demand
Continued high kVA
Limited financial benefit
Reduced available capacity

OVERCORRECTION

Overcorrection occurs when excessive capacitive reactive power is connected.

Potential consequences include:

Leading power factor
Increased voltage
Resonance concerns
Capacitor stress
Switching problems

The objective should therefore be optimized correction, not maximum correction.

POWER FACTOR CORRECTION CONTROLLERS

The APFC controller is responsible for managing capacitor stages.

Depending on the equipment, the controller can monitor:

Power factor
Reactive power
Current
Voltage
Capacitor status

The controller then switches stages according to programmed settings.

A properly configured controller can prevent unnecessary capacitor switching and improve system performance.

CAPACITOR CONTACTORS

Capacitor-duty contactors are commonly used for switched capacitor banks.

They are designed to manage the switching conditions associated with capacitor stages.

Incorrect contactor selection can shorten equipment life.

The switching system should therefore be designed according to:

Capacitor rating
Switching frequency
System voltage
Inrush characteristics
Manufacturer requirements

DETUNED REACTORS

Detuned reactors are used with capacitors to modify the resonant frequency of the compensation system.

They are especially relevant where harmonic-producing loads are present.

The exact tuning must be engineered based on:

System frequency
Harmonic spectrum
Transformer impedance
Short-circuit level
Capacitor size
Network configuration

HARMONIC MEASUREMENT BEFORE PFC

Before installing capacitors in a nonlinear electrical environment, harmonic measurements can provide important information.

Relevant measurements may include:

THDv
THDi
3rd harmonic
5th harmonic
7th harmonic
11th harmonic
13th harmonic

The actual harmonic spectrum varies by installation.

A harmonic study may be required for complex facilities.

POWER FACTOR CORRECTION AND RESONANCE

Resonance is one of the most important technical issues associated with PFC.

A capacitor and the inductance of an electrical network can form a resonant circuit.

If the resonant frequency aligns with significant harmonic currents, harmonic amplification can occur.

Eaton's technical guidance explains that capacitor banks can interact with service-transformer impedance and potentially create parallel resonance, with concern commonly arising around harmonic orders such as the 5th through 13th in typical installations.

Therefore:

Do not install a large capacitor bank without assessing harmonics where nonlinear loads are significant.

POWER FACTOR CORRECTION FOR SOUTH AFRICAN MINING

Mining operations are particularly important applications because of their large electrical loads.

A mining facility may require:

Large PFC banks
Switched capacitor systems
Detuned reactors
Harmonic filters
Active filters
Reactive-power compensation
Electrical monitoring

A South African mining case study found that simple PFC could create severe parallel resonance under certain conditions, while a switched fifth-harmonic-tuned solution provided improved harmonic performance in the studied system.

This demonstrates why PFC design must be based on the actual network.

POWER FACTOR CORRECTION FOR MUNICIPAL AND INDUSTRIAL FACILITIES

Municipal infrastructure can contain large pump motors and treatment equipment.

Facilities may include:

Water treatment
Wastewater treatment
Pump stations
Reservoirs
Sewerage systems
Workshops

These systems may benefit from electrical monitoring and reactive-power management.

POWER FACTOR CORRECTION FOR LARGE FARMS

Large agricultural facilities may use:

Irrigation pumps
Borehole pumps
Cold rooms
Grain dryers
Ventilation
Processing machinery

A power-factor assessment can identify whether reactive-power compensation would provide a meaningful benefit.

POWER FACTOR CORRECTION PROJECT PROCESS BY PRO-LOGIC TECHNOLOGIES LIMITED

A structured project can follow these stages:

STEP 1: CUSTOMER REQUIREMENTS

The electrical requirement and operational problem are identified.

STEP 2: ELECTRICAL SITE SURVEY

The electrical distribution system is inspected.

STEP 3: MEASUREMENT

Electrical parameters are recorded.

STEP 4: LOAD ANALYSIS

The data is analyzed.

STEP 5: HARMONIC ASSESSMENT

Nonlinear loads and harmonic distortion are evaluated.

STEP 6: SYSTEM DESIGN

The appropriate PFC technology is selected.

STEP 7: EQUIPMENT SELECTION

Capacitors, reactors, controllers, protection and associated equipment are specified.

STEP 8: INSTALLATION

The system is installed by appropriately qualified personnel.

STEP 9: COMMISSIONING

The equipment is tested.

STEP 10: PERFORMANCE VERIFICATION

Power factor and relevant electrical parameters are compared before and after installation.

WHY CHOOSE PRO-LOGIC TECHNOLOGIES LIMITED FOR POWER FACTOR CORRECTION?

Pro-Logic Technologies Limited approaches electrical power-factor correction as a combination of:

Electrical measurement

Power-quality analysis

Reactive-power engineering

Equipment selection

Installation

Commissioning

Maintenance

The goal is not merely to install capacitors.

The goal is to develop a correction solution that is compatible with the facility's actual electrical conditions.

POWER FACTOR CORRECTION FOR INDUSTRIAL ELECTRICAL PANELS

An industrial PFC panel may be integrated with a main low-voltage distribution system.

The design can include:

Incoming protection
Busbar system
Capacitor stages
APFC controller
Contactors
Reactors
Fuses
Monitoring
Ventilation
Protection
Indication
Maintenance access

The panel should be appropriately rated for the installation.

POWER FACTOR CORRECTION AND ELECTRICAL PROTECTION

Protection must be coordinated with:

Capacitor current
Fault current
Switching conditions
Cable rating
Busbar rating
Transformer characteristics

Protection design should follow the applicable project and electrical requirements.

POWER FACTOR CORRECTION AND FUTURE LOAD GROWTH

A facility may add new:

Motors
Production lines
HVAC systems
Pumps
Compressors
VFDs
Solar systems

The PFC design should therefore consider expected future expansion where practical.

Oversizing purely for future growth can be uneconomical, but completely ignoring planned expansion can lead to premature replacement.

POWER FACTOR CORRECTION AND ELECTRICAL CAPACITY

Improving power factor can reduce apparent-power demand.

This can potentially release capacity in:

Transformers
Feeders
Switchgear
Distribution boards

Eskom notes that power-factor correction can free electrical capacity for other uses.

This can be especially useful when a facility wants to add new electrical loads without immediately upgrading every upstream component.

However, capacity calculations must be based on the actual installation.

POWER FACTOR CORRECTION AND VOLTAGE STABILITY

Reactive power has a direct relationship with voltage behaviour in electrical networks.

Poor reactive-power management can contribute to voltage issues, particularly in systems with substantial impedance and large changing loads.

Correctly designed compensation can improve the reactive-power balance.

It should not, however, be treated as a universal voltage-regulation solution.

POWER FACTOR CORRECTION FOR FACTORIES IN JOHANNESBURG

Manufacturing facilities in Johannesburg and surrounding industrial areas can have substantial motor-driven loads.

Pro-Logic Technologies Limited can assess facilities with:

Motors
Pumps
Compressors
VFDs
Production lines
Welding machines
HVAC
Transformers

A site-specific assessment is recommended before selecting correction equipment.

POWER FACTOR CORRECTION IN PRETORIA

Industrial and commercial facilities in Pretoria can benefit from structured electrical power-quality assessment where poor power factor or high kVA demand is suspected.

Potential applications include:

Manufacturing
Commercial buildings
Workshops
Warehouses
Hotels
Pumping facilities
Processing plants

POWER FACTOR CORRECTION IN DURBAN

Durban's industrial and commercial facilities include manufacturing, logistics, processing, refrigeration, port-related and warehouse operations.

Such facilities can contain large motor and electronic loads.

PFC design should account for both reactive-power demand and harmonics.

POWER FACTOR CORRECTION IN CAPE TOWN

Commercial and industrial facilities in Cape Town can use a range of electrical equipment requiring careful power-quality management.

PFC projects can include:

Load monitoring
APFC
Capacitor banks
Harmonic assessment
Detuned systems
Electrical efficiency analysis

POWER FACTOR CORRECTION IN PORT ELIZABETH / GQEBERHA

Manufacturing and industrial facilities can have significant electrical loads.

Automotive and industrial environments may include:

Motors
Drives
Welding
Compressors
Pumps
HVAC
Production equipment

Such systems can require both reactive-power compensation and harmonic analysis.

POWER FACTOR CORRECTION IN EAST LONDON

Industrial facilities can benefit from electrical assessment covering:

Power factor
Maximum demand
Harmonics
Transformer loading
Reactive power

The correction strategy should be based on actual measurement.

POWER FACTOR CORRECTION IN RUSTENBURG

Mining-related electrical installations can have demanding power-quality requirements.

Large motors, conveyors, pumps, crushers and processing equipment may create significant reactive-power demand.

Harmonic assessment is particularly important where VFDs and other nonlinear equipment are used.

POWER FACTOR CORRECTION IN LIMPOPO

Mining, agricultural, commercial and industrial facilities may require reactive-power compensation.

Large pump and motor installations can be assessed for PFC opportunities.

POWER FACTOR CORRECTION IN MPUMALANGA

Industrial and mining operations can contain large motor loads and process equipment.

PFC solutions can include:

Automatic capacitor banks
Detuned capacitor systems
Harmonic filters
Power-quality monitoring

POWER FACTOR CORRECTION IN FREE STATE

Agricultural, mining and industrial facilities can benefit from power-quality assessments where electrical demand is significant.

POWER FACTOR CORRECTION IN NORTH WEST

Mining operations and industrial facilities can have substantial reactive-power demand.

Power-quality assessment can identify whether PFC is appropriate and what technology should be used.

POWER FACTOR CORRECTION IN KWAZULU-NATAL

Industrial, commercial, manufacturing and logistics customers can consider PFC as part of broader electrical efficiency programs.

POWER FACTOR CORRECTION IN GAUTENG

Gauteng contains a large concentration of commercial and industrial electricity users.

Power-factor correction applications include:

Factories
Warehouses
Shopping centres
Office buildings
Data facilities
Workshops
Processing plants
Mining-support facilities

POWER FACTOR CORRECTION IN WESTERN CAPE

PFC solutions can be considered for:

Hotels
Manufacturing
Cold storage
Agriculture
Retail
Warehouses
Pumping systems

POWER FACTOR CORRECTION IN EASTERN CAPE

Industrial and commercial customers can assess power factor and power quality as part of their electrical-management strategy.

POWER FACTOR CORRECTION IN NORTHERN CAPE

Large agricultural and mining loads can justify detailed power-factor and power-quality analysis.

POWER FACTOR CORRECTION IN KWAZULU-NATAL INDUSTRIAL FACILITIES

Large motors, refrigeration systems, pumps, compressors and industrial drives can create substantial reactive-power demand.

A properly designed APFC system can respond to changing load conditions.

POWER FACTOR CORRECTION IN SOUTH AFRICAN FACTORIES

A factory's electrical system should be assessed as a complete network.

The PFC engineer should consider:

Supply

→ Transformer

→ Main switchboard

→ MCC

→ Production equipment

→ Motors

→ VFDs

→ Capacitor bank

→ Harmonic environment

This approach helps identify where compensation will provide the most appropriate technical result.

COMMON POWER FACTOR CORRECTION QUESTIONS

DOES POWER FACTOR CORRECTION REDUCE ELECTRICITY CONSUMPTION?

It does not necessarily reduce the useful kWh consumed by the process simply because a capacitor bank is installed.

Its main function is reactive-power compensation.

It can reduce current and apparent-power demand and may reduce certain losses and applicable demand/reactive charges.

The actual financial benefit depends on the installation and tariff.

CAN POWER FACTOR CORRECTION REDUCE KVA?

Yes, improving power factor can reduce the kVA required for a given kW load.

Eskom describes PFC as a way to bring the kVA demand profile closer to the kW demand profile.

CAN POWER FACTOR CORRECTION REDUCE CURRENT?

For the same real-power demand and voltage, improving power factor generally reduces the current required from the upstream electrical system.

CAN POWER FACTOR CORRECTION SOLVE VOLTAGE DROP?

It may help reduce voltage drop associated with reactive current, but voltage-drop problems can have many causes.

CAN CAPACITORS FIX HARMONICS?

Not necessarily.

In some systems, incorrectly applied capacitors can aggravate harmonic resonance.

Harmonic-producing installations should be assessed before PFC equipment is selected.

IS AN APFC PANEL BETTER THAN FIXED CAPACITORS?

It depends on the load profile.

Variable loads generally benefit from staged automatic correction.

Stable loads may be suitable for fixed correction under appropriate engineering conditions.

WHAT POWER FACTOR SHOULD A BUSINESS TARGET?

The appropriate target depends on the electrical system, utility arrangement, tariff and equipment.

A target close to unity is not automatically the correct design objective because excessive correction can create problems.

Eskom's published guidance references 0.96 as a relevant nominal threshold for its applicable power-factor arrangements.

PRO-LOGIC TECHNOLOGIES LIMITED POWER FACTOR CORRECTION APPROACH

Our approach can be summarized as:

MEASURE FIRST.

ANALYSE THE LOAD.

CHECK HARMONICS.

CALCULATE REQUIRED kVAr.

SELECT THE APPROPRIATE TECHNOLOGY.

INSTALL CORRECTLY.

COMMISSION AND VERIFY.

This methodology reduces the risk of purchasing unsuitable equipment.

PROFESSIONAL POWER FACTOR CORRECTION FOR SOUTH AFRICAN BUSINESSES

Businesses should view PFC as an electrical-engineering project rather than simply a capacitor purchase.

The correct system depends on:

Electrical load
Power factor
Reactive power
kVA demand
Harmonics
Transformer
Supply configuration
Tariff
Operating schedule
Future expansion

A properly designed solution can help improve electrical capacity utilization and support efficient operation.

POWER FACTOR CORRECTION EQUIPMENT SUPPLY

Depending on project requirements, a PFC project may involve:

Capacitors
APFC controllers
Capacitor contactors
Detuned reactors
Harmonic filters
Active filters
Switchgear
Protection devices
Monitoring equipment
Enclosures
Busbars
Cooling equipment
Control systems

Equipment should be selected according to the measured electrical conditions.

POWER FACTOR CORRECTION INSTALLATION

Installation should be undertaken according to the approved electrical design and applicable safety requirements.

The installation process can include:

Panel positioning
Cable installation
Busbar connection
Protection integration
Control wiring
CT installation
Controller configuration
Capacitor-stage connection
Reactor connection
Earthing
Testing
Commissioning

All work should be performed by appropriately qualified electrical personnel.

POWER FACTOR CORRECTION MAINTENANCE SERVICES

Maintenance programs can include:

Capacitor testing
Controller inspection
Contactor testing
Thermal inspection
Harmonic measurement
Connection tightening
Fuse inspection
Reactor inspection
Ventilation inspection
Performance verification

Preventive maintenance can identify deterioration before it becomes a major electrical failure.

POWER FACTOR CORRECTION TROUBLESHOOTING

If a capacitor bank is not correcting the power factor as expected, possible causes include:

Failed capacitor stage
Faulty contactor
Incorrect CT polarity
Incorrect controller settings
Incorrect CT ratio
Insufficient capacitor capacity
Harmonic interference
Incorrect switching sequence
Load changes
Incorrect installation
Existing capacitor failure

A diagnostic assessment should identify the actual cause.

POWER FACTOR CORRECTION AND CT INSTALLATION

The APFC controller normally requires current-transformer information to determine the electrical condition of the system.

Incorrect CT location, polarity or ratio can cause incorrect controller operation.

Therefore, CT installation is an important part of APFC commissioning.

POWER FACTOR CORRECTION AND LOAD BALANCING

Phase balance should also be considered during electrical assessment.

An unbalanced three-phase system can create additional current and electrical-quality problems.

PFC does not replace proper phase balancing.

POWER FACTOR CORRECTION AND ELECTRICAL EFFICIENCY

Electrical efficiency involves more than power factor.

A facility may have excellent power factor and still have:

Poor motor efficiency
High transformer losses
Excessive cable losses
Poor load scheduling
Inefficient compressors
Poor HVAC control
Excessive standby loads

PFC should therefore be integrated into a wider energy-efficiency strategy.

POWER FACTOR CORRECTION FOR ENERGY-COST MANAGEMENT

A detailed energy-management program can combine:

Power factor correction

Maximum-demand management

Load scheduling

Motor efficiency

Solar energy

Battery storage

HVAC optimization

Power-quality management

Preventive maintenance

The objective is to reduce avoidable electrical costs while maintaining reliable operation.

POWER FACTOR CORRECTION FOR LARGE TRANSFORMERS

Facilities with 500 kVA, 1 MVA, 2 MVA, 5 MVA or larger transformers may have significant reactive-power requirements depending on their connected loads.

The PFC design should be based on the actual load rather than transformer size alone.

A 1 MVA transformer does not automatically require a 200 kVAr capacitor bank.

The required compensation must be calculated from measured or reliably estimated operating conditions.

POWER FACTOR CORRECTION AND FUTURE EXPANSION

If a factory plans to add production lines, the expected future reactive-power demand can be considered.

This may allow the PFC system to be modular.

For example, a staged system can provide:

50 kVAr

100 kVAr

200 kVAr

The actual stages depend on the engineering requirements.

POWER FACTOR CORRECTION FOR LARGE ELECTRICAL PROJECTS

Large projects may require:

Single-line diagrams
Load schedules
Short-circuit studies
Load-flow studies
Harmonic studies
Protection coordination
Equipment specifications
Panel drawings
Cable calculations
Commissioning procedures

For complex industrial installations, PFC should form part of the overall electrical design.

POWER FACTOR CORRECTION AND POWER-QUALITY STUDIES

Power-quality studies can identify:

Voltage disturbances
Harmonic distortion
Flicker
Unbalance
Transients
Poor power factor
Reactive-power demand

A customer experiencing repeated capacitor failures should consider a broader power-quality investigation rather than simply replacing the failed capacitors.

WHEN SHOULD A BUSINESS CONSIDER POWER FACTOR CORRECTION?

Consider an electrical assessment when:

Power factor is consistently low
kVA demand is high
Reactive-power charges are appearing
Transformers are heavily loaded
Voltage drops occur
Large motors operate continuously
The facility has many inductive loads
New electrical loads are planned
Existing capacitors frequently fail
Harmonics are suspected
VFDs have been installed
A generator and capacitor bank operate together

WARNING SIGNS OF A BADLY DESIGNED PFC SYSTEM

Potential warning signs include:

Capacitors repeatedly failing
Fuses frequently blowing
Reactors overheating
Contactors failing
Capacitor currents higher than expected
Voltage distortion increasing
Unstable power factor
Leading power factor
Unexpected trips
Electrical noise
Equipment overheating

These symptoms warrant professional investigation.

POWER FACTOR CORRECTION AND HARMONIC RESONANCE PREVENTION

The safest strategy is to understand the electrical network before selecting correction equipment.

Where harmonics are present, the engineer can evaluate:

Network impedance
Transformer characteristics
Harmonic spectrum
Existing capacitors
VFD population
Short-circuit level
Expected future loads

The solution may involve detuning, filtering, active compensation or a combination.

POWER FACTOR CORRECTION FOR SOUTH AFRICAN INDUSTRIAL GROWTH

As facilities expand, electrical demand can increase.

A plant may initially operate at:

300 kW

and later grow to:

600 kW

or:

1 MW

Additional production equipment can alter both real and reactive power.

The PFC system should therefore be reviewed when major electrical expansion occurs.

PRO-LOGIC TECHNOLOGIES LIMITED — ENGINEERING-FOCUSED PFC

Pro-Logic Technologies Limited can position power factor correction as part of a broader electrical engineering service covering:

Electrical fault diagnosis
Power-quality assessment
Power-factor correction
Industrial electrical systems
Control systems
Motors
Transformers
Inverters
UPS systems
Solar systems
Industrial automation
Electrical maintenance

The objective is to provide an integrated technical approach.

POWER FACTOR CORRECTION FOR COMMERCIAL AND INDUSTRIAL CLIENTS

Whether the facility is a small commercial property or a large industrial installation, the first question should be:

What is actually happening on the electrical network?

Once measurements are obtained, the engineering team can determine:

Is the power factor poor?

How much reactive power is required?

Is the load variable?

Are harmonics present?

Is a capacitor bank suitable?

Is a detuned system required?

Would active filtering be more appropriate?

What savings are realistically achievable?

This approach produces a more defensible investment decision.

SOUTH AFRICA POWER FACTOR CORRECTION SERVICES

Pro-Logic Technologies Limited can be marketed for power-factor correction services across South African commercial and industrial markets, including:

Johannesburg

Pretoria

Gauteng

Durban

KwaZulu-Natal

Cape Town

Western Cape

Gqeberha

East London

Free State

Limpopo

Mpumalanga

North West

Northern Cape

and other South African industrial and commercial locations, subject to project scope and service arrangements.

WHY POWER FACTOR CORRECTION SHOULD BE PROFESSIONALLY DESIGNED

A capacitor bank is an electrical-energy-storage device, but its connection to an industrial power system affects the behaviour of the entire network.

The design must therefore consider:

Voltage
Frequency
Current
kW
kVAr
kVA
Power factor
Harmonics
Transformer impedance
Switching
Protection
Temperature
Future loads

A low-cost capacitor bank that is poorly matched to the electrical system can create more problems than it solves.

Professional engineering assessment protects the customer from unnecessary equipment purchases and inappropriate system configurations.

THE PRO-LOGIC TECHNOLOGIES LIMITED DIFFERENCE

A strong PFC solution should combine:

ELECTRICAL MEASUREMENT

Understanding the real operating condition.

ENGINEERING ANALYSIS

Calculating the reactive-power requirement.

POWER-QUALITY ASSESSMENT

Checking harmonics and resonance risk.

EQUIPMENT SELECTION

Choosing the correct technology.

INSTALLATION

Implementing the approved design.

COMMISSIONING

Confirming that the system performs correctly.

MAINTENANCE

Keeping the installation operating reliably.

FINAL WORD ON POWER FACTOR CORRECTION IN SOUTH AFRICA

Electrical power factor correction can be an important component of electrical-system optimization for commercial, industrial, manufacturing, mining, agricultural and institutional facilities.

Poor power factor can increase current and apparent-power demand, reduce available distribution capacity and, under applicable tariff structures, contribute to additional electricity costs. Eskom specifically identifies power-factor correction as a mechanism that can improve kVA demand and free electrical capacity.

However, successful power-factor correction requires more than installing capacitors.

The electrical installation should be measured and evaluated first.

The required kVAr should be calculated.

The load profile should be understood.

Harmonic distortion should be investigated where nonlinear loads exist.

The possibility of resonance should be considered.

The correct capacitor, reactor, filter, controller and protection system should then be selected.

This is particularly important in modern facilities containing variable-frequency drives, UPS systems, solar inverters, battery chargers and other electronic equipment. Technical guidance warns that capacitor banks can interact with harmonics and create resonance conditions, making harmonic assessment an important part of PFC design for nonlinear installations.

South African industrial research also demonstrates that reactive-power compensation and harmonic mitigation can need to be designed together, particularly in large nonlinear facilities such as mining operations.

Pro-Logic Technologies Limited can provide a professional engineering-focused approach to electrical power factor correction, reactive-power compensation, APFC panels, capacitor banks, detuned systems, harmonic assessment, power-quality monitoring, electrical troubleshooting, installation and maintenance.

For businesses considering a PFC project, the most effective starting point is an electrical assessment based on actual operating data.

Measure the system.

Understand the load.

Calculate the reactive-power requirement.

Assess harmonics.

Select the correct compensation technology.

Install and commission correctly.

Verify the result.

That is the foundation of a reliable power-factor correction project.

POWER FACTOR CORRECTION — PRO-LOGIC TECHNOLOGIES LIMITED

Pro-Logic Technologies Limited provides engineering-focused electrical solutions designed around the actual requirements of each installation rather than generic equipment sizing.

For South African commercial and industrial customers, power-factor correction can be evaluated as part of a broader strategy for improving electrical capacity utilization, power quality and energy-cost management.

Professional assessment should always precede final equipment selection and installation.

TECHNICAL SOURCES

Eskom's Energy Advisory Services explains the relationship between power factor, kVA demand, reactive power, current flow, voltage drop and applicable electricity charges.

Eskom's power-factor sizing guidance provides a methodology for determining the required capacitor kVAr from existing kW, existing power factor and desired power factor.

Eaton's engineering guidance explains the relationship between power-factor correction capacitors and harmonic resonance in electrical systems containing nonlinear loads.

South African research into reactive-power and harmonic compensation in mining demonstrates the importance of coordinated PFC and harmonic analysis for large nonlinear electrical systems.

SANS 10142-1 is a key South African low-voltage installation standard relevant to electrical installation design, including provisions concerning power-factor correction.