Magnum Inverter Internal NTC fault

velo47 · 07-22-2018, 06:22 PM

Hi Everyone,
We just got back from a great trip through Utah, Idaho., Montana, Wyoming. Hard to beat!

Anyway, the first night we stayed at a campground on the Middle Provo in Utah, where I plugged into shore power. A few minutes later, I got in and saw a fault on the Magnum battery monitor. The fault code was "Internal NTC," which means there was an internal temperature spike in the inverter (also a Magnum).

I immediately turned off the breakers, which had not tripped, and unplugged. I did an inverter reset which cleared the fault.

Now the inverter appears as if it is working when turned on, and you can see the battery voltage drop, but we get no power to any of the AC plugs or microwave. We get no AC power when plugged into shore power either.

Any ideas?
Thanks,
Matt

MountainBikeRoamer · 07-22-2018, 06:33 PM

Quote:

Originally Posted by velo47

I immediately turned off the breakers, which had not tripped, and unplugged. I did an inverter reset which cleared the fault.

Now the inverter appears as if it is working when turned on, and you can see the battery voltage drop, but we get no power to any of the AC plugs or microwave. We get no AC power when plugged into shore power either.

Any ideas?
Thanks,
Matt

Hehe, don't take this the wrong way....but now that your inverter has reset and cleared out any faults.....did you remember to turn all of those breakers ***back on again*** ?

velo47 · 07-22-2018, 06:37 PM

Hehe!
I won't take it the wrong way because I thought that too! We have no AC with the breakers on (or off).

Fitz · 07-22-2018, 06:50 PM

There is a press-to-reset AC circuit breaker on the side of the Inverter/Charger, page 5 of the 2016 manual. I had to locate this once, tough to find on mine under the seat but it is there and somewhat accessible. Suggest you check it (if you haven’t already).

Scalf77 · 07-22-2018, 07:19 PM

I agree Fitz, the ac Input breaker may need to be reset.

The NTC failure is specifically overheating FET's on the FET bridge, make sure you have good airflow, and the fan's are working.

Greg

velo47 · 07-22-2018, 07:23 PM

Thanks Tim,
Didn't know about the circuit breaker but just checked and it's not tripped.Darn.

Scalf77 · 07-22-2018, 07:29 PM

I assume your charger is also not working when plugged in. If it is working then I would suspect that you need to reset the GFIC plugs.

-greg

velo47 · 07-23-2018, 01:43 PM

Thanks everyone for helping an electricity challenged beginner,

Greg, I think the vents were clear but we were packed pretty heavy for 4 people for 2 weeks and someone might have crammed something up against the grate. We'll be careful of that in the future.

I hadn't checked the charger until you mentioned it, because we didn't use shore power again after the fault. It is working. I totally forgot about the GFIC, duh! It had popped and I tried to reset but it wouldn't until I turned on both the inverter and the breaker. We now have power again! So glad it wasn't more serious.

Tim, thanks for the info about the circuit breaker on the inverter. I didn't even see that in the manual. Good to know for the future.

Mike, it was something almost as simple as you suggested. I fretted about this for 2 weeks while we were on the road. Always check the easy stuff first!

Scalf77 · 07-23-2018, 02:06 PM

Glad to see that you have it figured out. Yes, the GFIC outlets need to have powered applied in order for the reset to work.

-greg

Fitz · 07-23-2018, 02:35 PM

Ditto Greg’s comment above, now get back out on the road and use it some more!