Even after installation, residual current devices need regular testing to confirm they still function correctly. Residual current device (RCD) testing is a quick but essential safety check for any home.
Why It Matters
An RCD that fails to trip during a fault offers no protection, even though it may appear to be working normally. Residual current device (RCD) testing confirms that these devices respond correctly and within the required time when a fault is detected.
What to Expect During the Process
- Visual Inspection – The electrician checks the RCD for any visible damage or signs of wear.
- Test Button Check – The built-in test button is pressed to confirm the device trips as expected.
- Trip Time Measurement – Specialized testing equipment measures how quickly the RCD responds to a simulated fault.
- Sensitivity Testing – The device's sensitivity to different levels of current leakage is checked against safety standards.
- Recording Results – All test results are documented, including trip times and sensitivity readings.
- Recommendations – If the device fails any test, the electrician will recommend repair or replacement.
This testing is recommended at least once a year, or every few months for high-use commercial properties.
Common Mistakes to Avoid
Do not ignore an RCD that fails to trip during testing, as this is a serious safety issue. Relying only on the built-in test button without proper trip-time testing can also miss underlying problems.
Estimated Cost of Residual Current Device (RCD) Testing
| Service | Estimated Cost (KES) |
|---|---|
| Single RCD test | 1,500 – 4,000 |
| Multiple RCD testing (per unit) | 1,200 – 3,000 |
| Full distribution board RCD testing | 8,000 – 18,000 |
| Replacement of faulty RCD (if needed) | 5,000 – 12,000 |
Prices depend on the number of devices tested and the testing equipment used.
Residual current device (RCD) testing should be part of your regular home maintenance routine. A quick annual test can confirm that this important safety device will work when you need it most.