EVSE testing is the function of confirming the safety and performance of electric vehicle supply equipment. The national infrastructure of EVSE is increasing all the time, and with it comes a common testing requirement under the standard BS7671. This ensures that all the different types of EVSE are tested using the same parameters and under the same conditions.
It is important to note that EVSE doesn’t just include the charging unit for the electric vehicle, but also includes cables and connectors which make up the safe operation of the charging unit. All of these need to be visually inspected during the testing process, in addition to the electrical testing of the charging unit itself.
How EVSE is tested
Of course it is not always practical to have an actual EV on-site for EVSE testing purposes, so the adaptor connected to your testing equipment acts as the EV and provides the conditions you would normally face when using EVSE. Therefore, the test required by BS7671 is effectively simulating the various charging states an EV would present. You can carry out these tests using one of several different EVSE testing products supplied by Test Instrument Solutions, such as the TIS EV-TEST100, the MFT-ECO or the award-winning MFT-PRO, which is a multi-function tester with EVSE testing capabilities.
What is required in EVSE testing?
The tests required as per BS7671 include the following:
- Proximity Pilot State Test – a simulation of the full current load of the charger, which is usually at 32A or 7.0kW.
- Control Pilot State Test – this simulates the operation of the charger in various charging states:
- Open – where the EV is not connected
- Where the EV is connected but charging is not required
- Where the EV is connected and charging
- The test equipment should be maintained at 32A and the dial changed to select each test, allowing time for the charger to settle in each case. For test 3 when the charger is charging, you are then required to carry out three more tests:
- Earth loop impedance
- 6mA RDC-DD test – this ensures the charger trips when any DC component is at or above 6mA
- Type A, Type F or Type B RCD test – this ensures that the A, F and B RCDs on the charging unit or the final charger circuit comply with BS EN 61008 or BS EN 61009 as appropriate.
- The most recent version of the standard, BS 7671:2018+A2:2022, also requires that Initial Verification inspection and testing is conducted on the charger final circuit if you are testing a new installation. In this case an Electrical Installation Certificate should also be issued.
There are also some advanced tests which can be carried out on the EVSE using the TIS equipment, to further check and analyse the safety and performance, which include:
- Insulation resistance test
- Power quality
- Loop impedance
When should EVSE testing be carried out?
Most EVSE will be used frequently and repeatedly, so it is important that safety and performance is verified regularly, because cables and connectors get damaged over time, which increases the risk of electric shock for the user. It is also important to check the RCDs in the system are working so that the system trips when it is supposed to and there is no presence of dangerous voltages.
So EVSE should be tested as above:
- Upon installation
- For periodic service and maintenance
- When troubleshooting problems with the EVSE.
Video Demonstration
Below is a video using the TIS EV-TEST100 in manual mode:
Please note that this section is for information purposes only. Anyone using equipment referred to in this section must be suitably qualified and/or experienced within the respective field. If in doubt before use, please consult a qualified electrician or engineer & thoroughly read all instruction booklets.