In addition, you should be aware of ground faults. Ground faults can result from inappropriate control wiring such as THHN or TEW which are not designed for outdoor use. The insulation will crack slightly and indicate a fault on damp or rainy days. Therefore, it is recommended that you DO NOT use THHN, TEW wiring, or any other indoor wiring. Faults can also occur by a power lug touching the frame. Ground faults can create problems for your components (e.g. on-board chargers, etc.) and can shock you. Therefore, it is important to periodically check for faults and eliminate them.
1. Inspect for ground faults by checking the voltage between the negative terminal
of the charging connection and the vehicle frame. Remember this is high voltage.
2. Repeat Step 1 using the positive terminal of the charging connection and the vehicle frame.
3. If you get voltage readings, it is indicative of a fault to ground in the power or control wiring.
The location of the fault is proportional to the readings obtained. For example, if the negative lead to
frame reading is 21 Volts and the positive to frame reading is 101 volts, the fault is located between the
third and fourth battery.
4. Locate and disconnect the suspected wire.
5. Repeat Steps 1-2 to confirm that this was the ground fault.
6. Correct problem.
7. Repeat Steps 1-2 to confirm problem has been corrected.