donhrtf avatar image
donhrtf asked

Phoenix Inverter 12/3000/230V, Failed on both 12v input and 230v output

2 problems possibly related

I have a 12/3000/230v inverter installed with 600 AH Life po4 battery. 640 watts solar to charge with Victron MPPT 150/70. Almost never plug in.

Usage thus far is low, 400v-800w, it is mainly installed for higher loads later in the trip, small elect heater and small AC, sm induction hot plate etc.

I also have a 12/600W/120volt US inverter installed. In a separate circuit out of the battery pack. separate 12v and 120V outlets. It works fine. We run our laptops off this.


About 2 months after install I noticed a slightly lower voltage each night for about 4 days. 13.2 was average, then 13v then 12.8 then 12.5 Average sun etc. then the low volt alarm came on (in the middle of the night of course). Below 8 volts!! I pulled the fuse to the unit (400amp) and the problem stopped. The batteries pack was not only drained on a 'volt' level but the capacity (AH) was reduced to almost zero. It took a couple weeks to charge back up with solar because we were in the UK and the sun does not shine much there.


I decided to go to a campground and plug in to 'top off the batteries" ( I have a Votronic PB 1260 charger) When I did this the campground breaker tripped. I later went to a second campground and the same thing happened. I disconnected the 230v from the Phoenix inverter and the problem stopped. (230v in the truck is good etc. Campground breaker is happy etc.)

While plugged in at campground I checked the 230v wires coming into (out) of the inverter and the load and neutral were wired to the inverter correctly. Line, neutral etc.

The wires coming from the campground 'in' and the inverter 'in'(from inverter to house) are both wired into the same box. This is prior to the "house breaker and house GFCI"

Is it ok for the 230v to "backfeed' into the inverter? It should know this and disconnect? when plugged in.

Am I missing something here? I have run this by the electricians in the family and they think something must be wrong inside the inverter. How can I test this further? My supplier is more of a solar panel guy and not as much help as I would like.

Other trouble shooting advice would be good.

Thank you in advance.


Phoenix Inverter
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1 Answer
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

Could you give us a simple wiring diagram, please?

If I understand you correctly the inverter output and "campground" input are wired together!? like so:

This could be the problem. You should use a relay or a switch to separate them from each other, like so:

As long as the "campground" input is not plugged in the energy can come from the inverter. If the "campground" input is plugged in the relay K1 will engage and energy can come from there without going into the inverter.

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1 comment
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donhrtf avatar image donhrtf commented ·

Thanks for this, I am not sure my previous comment posted.

Yes the upper drawing is correct. I thought the inverter 'knows' when it is plugged in and shut down the power from the incoming camp side. I was thinking of a switch there but a relay would be automatic.

Any thought on Problem #1)? The 12v drain that occurred prior to this problem? I have not done any further testing other than to install a Blue Sea relay/switch there to shut of 12v side upon low volt condition. I have not used the inverter since.

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