28 September 2021
Explanation of XW+ welded relay faults
If you receive one of the Welded Relay errors on an XW+ Inverter/Charger (F17 through F22), it is possible that one of the AC transfer relays has failed, but in order to rule out wiring errors or improper operation of the AC bypass breakers, you should take the following steps:
First, verify that the AC Bypass Breakers are in the OFF position. If the AC Bypass breakers are switched ON while the Inverter Output breakers are also ON, the XW will sense that an AC voltage source is present on its AC Output terminals and will register one of these faults.
Any outside source of AC presented to the input and output of the XW simulataneously can potentially weld the relay. THIS IS CONSIDERED A MIS-WIRE AND MAY VOID THE WARRANTY. The Power Distribution Panel (865-1015-01) comes prewired for a single XW and has an interlock to prevent both the inverter output breakers and the AC bypass breakers from being in the ON position simultaneously. When installing dual XW units, ensure that the AC breakers and interlock plate (comes with 2nd inverter extension kit Pt # 865-1020) are installed per the installation manual to prevent this issue. Any system with 3 XW units or more must incorporate and external bypass switch.
If the AC Bypass Breakers are off, power the inverter OFF at the AC and DC breakers and disconnect the AC wires from the Inverter's AC Out terminals at the inverter itself. Power the inverter back on and see if the fault clears. Have a qualified person measure across the disconnected output wires while either grid or generator power is being supplied to XW input (AC1 or AC2 LEDs blinking or solid). Make sure no AC voltage is measured across the disconnected output wires.
If the fault does not clear, it is likely one of the AC Transfer Relays is actually welded closed. In this case, a replacement of the AC Board will be necessary. If this was caused by a mis-wire, it will not be covered under warranty. Contact Technical Support at 866-519-1470 for more information regarding parts and availability..