Hi,
I have had my panel in storage for a few months, When it is connected to my step down i get a positive ground issue that is unsolvable
I have tried troubleshooting this and i haven’t come to a conclusion why it is happening.
Thanks
I’m not familiar with the FCI 7100 so I can only give general information on ground faults. Here are some basic things to look for.
Does the panel have a good ground reference? Sometimes the lack of a good ground reference can cause the ground fault sensing circuit to drift and give a false indication.
Since this was in storage, handling could cause metal fragments or strands of wire to become lodged on a circuit boards somewhere. Thoroughly check for such fragments on the boards.
Does the panel have batteries connected? Damaged batteries can leak and the acid can eat through the paint on the cabinet causing a ground fault.
What is the extent of the fault? With a voltmeter measure between chassis ground and the negative side of the power supply. Usually any negative terminal can be used (system common, negative battery terminal, etc). Normal voltage will be around half the power supply voltage give or take a volt or two. Near 0 volts or near full power supply voltage indicates a short to ground. Around 7 volts or 21 volts indicates a high resistance ground fault.
Does the ground fault still exist with all external wires removed from the panel? If it does that indicates a fault on a circuit board. It could be a failed component in the ground fault sensing circuit or a leaking component somewhere on a board. Modern FA panels have transient suppression components on the boards. The most often used suppressor is the metal oxide varistor (MOV). These typically are across each circuit (SLC, NACs, AUX Power, etc) and from one or both sides of the circuits to ground. These can develop leakage and cause a ground fault condition. In this case the board would need to be repaired by qualified personnel.
MOVs come in various styles and colors. Stand up versions look line disc capacitors. There are also surface mount technology (SMT) versions. If the component locations are silk screened on the board, the usual designation is RV.
Examples of stand up MOVs.
Examples of SMT MOVs.
Will have to find my step down, but it can’t be a metal shaving as it isn’t in a cabinet and the issue exists when no devices are connected
I think I will take it to be looked at.