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alin avatar image
alin asked

Short circuit on Smart Phoenix Inverter 12V 2000VA 230V

I have a Smart Phoenix Inverter 12V 2000VA 230V installed in my camper with a 12V 280AH battery and a JK-BMS attached. The BMS was off until recently, because the camper was not in use during the winter, so there was no power for the inverter.

When I turned on the BMS, it detected a short circuit on the output and after a full day of checking all the wires and circuits, I found that the inverter has a short on its DC input terminals even though the external fuse was intact. As per the manual, there's no internal fuse for this inverter.

How is this even possible? Any advice what to do with it or just send it back to the seller for repairs?

Phoenix Inverter
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klim8skeptic avatar image klim8skeptic ♦ commented ·

@alin did you pre charge the capacitors in the inverter?

Some BMS will chuck a fit at the inrush current when the inverter is first connected, and trip out on over current.

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pwfarnell avatar image pwfarnell commented ·

@alin Do not forget that putting a meter onto the DC input terminals will indicate a very low resistance because the meter is charging the large capacitors with a small current from the multimeter so it can look like a short.

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timdalrymple avatar image timdalrymple commented ·
I have a very similar problem with my new Victron phoenix 12/375. I was testing the unit to drive Starlink and I connected the inverter directly to the battery (no fuse). I later determined that the input terminals were shorted but this was after I melted the insulation off my wiring harness is less than 5 seconds and just avoided setting the camper on fire!

I then rewired the inverter and included a fuse. The fuse blew instantly when connecting the inverter. I measured a short on the input terminals. Snitched the unit on and off (unpowered) and the short was eliminated.

This is baffling to me. Does anyone have any suggestions for troubleshooting?

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2 Answers
Mike Dorsett avatar image
Mike Dorsett answered ·

Nest to test the inverter direct to a battery with a small external fuse - 20A or so. This should absorb the inrush current. Otherwise you could use a 12V tungsten light bulb as a precharge resistor, if the bulb stays lit, then the inverter is faulty.

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alin avatar image
alin answered ·

Hi all, thank you for the feedback.

I didn't precharge the inverter's capacitors before this happened, and I never had any problems. At least 2-3 times since I installed my battery, the inverter was disconnected from the battery (at least one time for several days) and it always just worked when the battery was reconnected.

Anyway, I followed your advice now and got a resistor to test with, but I had to wait a couple of days for it to arrive. Now I managed to test and it seems it keeps drawing current forever if I use the resistor, so I'm guessing it's a fault in the inverter as you said, Mike. I'll start dismantling it and will send it back for repairs.

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