It appears that is just a 400WATT Power Inverter... Didn't read the specs on it but you would want it to be a PURE SINE WAVE MODEL so that no matter what gets plugged into it won't go up in the infamous BLUE SMOKE thing... Electronics and MSW type Inverters don't do well being used together.
Should be pretty simple Install with two heavy wires going to the 12VDC Battery and a 120VAC outlet on it with GFCI breaker on it...
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Just trace back on the two Battery cables and remove them from where ever they tie into your battery setup... Then just simply unplug the 120VAC cable... Have no idea how this would be installed in your setup on the 120VAC side. If your 120VAC Plug Male connector is hot (Reads 120VAC with a multimeter) after you unplug it from the Power Inverter and have shore power ON then you will have a safety violation and you must remove the wiring connections. It would be very unsafe to have a hot male connector laying around still energized with 120VAC power. i.e. someone may have hooked up a 'widow maker' double male plug short cable to back feed your 120VAC receptacles when shore power or generator is not being used. A very bad and unsafe idea... Two guesses who the 'widow maker' will be...
A proper install would include a change-over 120VAC contactor when shore power or generator is not being used.
Easy to test out just use a multimeter to make sure 12VDC is feeding the unit and when turned on with nothing plugged into it you should read 120VAC at its receptacle... A 400 WATT 120VAC power Inverter would draw around 32 DC AMPS from your 12VDC battery connections when fully loaded down...
Most probably cause for failure is a dead 12VDC battery or bad 12VDC cables feeding it...
This can be replaced with a much smaller unit in size like maybe the 600WATT PURE SINE WAVE AIMS Power Inverter model PWRI60012S available from AMAZON for less than $150
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I use the 600WATT AIMS PSW Power Inverter with two drop cords from it feeding a multi-TAP Power Cord with one located in the Home entertainment area and the other cord going back to a table top near our bed area. Its not wired into the trailer system just a couple of
Multi-tap extension cords you can plug into when you need to power up something from 120VAC when off-grid somewhere... I have the multi-tap head mounted on the back of the table top with all wiring out of sight.. I usually only draw around 250-300WATTS from my 600WATT PSW Power Inverter with a few low wattage things... 300WATTS of 120VAC power will draw around 25AMPS from my 12V battery setup...
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Roy Ken
My Posts are IMHO based on my experiences - Words in CAPS does not mean I am shouting
Roy - Carolyn
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