A DIY MultiPlus (USA) 3000/120/120/50 installation on a boat by one of my very competent customers is tripping his shore power RCD.
The RCD is a 5mA trip on his 50A/250VAC split phase shore power supply. I am going to have him install a 30mA/100mSec RCD to remove that variable. Here is the procedure he has to go through when he returns to his home dock and brings shore power back aboard:
The RCD is a 5mA trip on his 50A/250VAC split phase shore power supply. I am going to have him install a 30mA/100mSec RCD to remove that variable. Here is the procedure he has to go through when he returns to his home dock and brings shore power back aboard:
- Also, as I’ve mentioned before, my home power setup has a 5mA trip GFCI breaker in the subpanel feeding the dock so much more sensitive than the 30mA seen in newer marinas. So let’s say I pull up to the dock with the inverter having been on during a trip. I plug in mains power while the inverter is “inverting” and when I turn on the breaker it immediately trips. I have to turn off the inverter, then go through the following power-up sequence for things to stabilize.
- Turn of all the boat’s breakers
- Turn inverter off
- Turn on Mains power to the boat
- Turn on non-inverted line1 and 2 breakers (can also now turn on individual breakers under those line breakers such as AC units)
- Turn on main breaker for inverted circuits but have no “sub breakers” under that main breaker on.
- Turn on the inverter – its LED show it in INVERT mode but after a few seconds it shifts to “MAINS” and subsequently starts charging batteries.
- I can then turn on the individual inverted breakers (refrigerator, ice maker, outlets, etc)
- All is good.
The feedback (input) relay will not close until after the N>G relay opens so what is causing the RCD to trips during the first changeover from inverter to pass through but once he goes through the procedure above, the Multi comes on line and is rock steady?
