What happens if a PV system has a ground fault?

In some cases, a ground fault will be easy to spot. High resistance generates heat, which may cause a fire and potentially extensive damage. Replace all impacted equipment and conductors. Ground faults can be a persistent issue for any PV system. They take a toll on system health and productivity.

Why do residential PV arrays have ground faults?

In some cases, PV ground faults are caused by modules with water intrusion, or by other more rare and exotic faults. The cost associated with residential ground fault mitigation is often higher than the system owner appreciates. This is one of the reasons why some residential PV arrays are not properly maintained and serviced.

What causes a ground fault in a PV inverter?

PV ground faults can periodic and intermittent. Typically moisture in the morning will induce an intermittent faults. The energy production from a given string will be switched off until the equipment dries up, and the inverter goes back online. The emazys Z200 has a build in ground fault detector.

What happens if a PV string circuit does not have a ground fault?

A PV string circuit without a ground fault will have open circuit voltage (Voc) between positive and negative conductors. It will have zero volts from positive to ground and from negative to ground. When a ground fault is present, measurement will show Voc between positive and negative conductors.

Do I need a grounding electrode for a PV array?

While a separate grounding electrode system is still permitted to be installed for a PV array, per 690.47 (B), it is no longer required to be bonded to the premises grounding electrode system. In PV systems with string inverters, the equipment grounding conductor from the array terminates to the inverter’s grounding bus bar.

Do solar inverters need a ground fault detection & interruption device?

Solar inverters must have a ground fault detection and interruption (GFDI) device to detect and stop ground faults. It can identify the ground fault, generate an error code, and shut down the inverter. The amount of current flowing through the ground fault required to trip the inverter's GFDI varies based on the inverter type.