Ground Fault Detection in Ungrounded Solar Arrays
Isolated (Ungrounded) Solar Arrays
A typical system would be considered to have good insulation with a resistance value of multiple
kilo ohms or mega ohms, and would be considered to have low insulation at the low kilo ohm to
less than one kilo ohm range. However, the value of a system's overall resistance may vary
depending on the number of loads, type of insulation used, age of the installation,
environmental conditions, etc.
Figure 1: Isolated DC array and inverter with BENDER iso-PV ground detector
Non-Isolated (Grounded) Solar Arrays
For DC systems, as well as AC systems that have varying voltages or power conversion equipment
including variable frequency drives, a special measurement signal is applied. BENDER's AMP Plus measurement principle,
found in devices such as the IRDH275, have the ability to be used universally in AC, DC, and AC/DC systems,
as well as overcoming adverse system conditions, such as high leakage capacitance.
Figure 2: Ground fault monitoring of a grounded array / inverter system