Inverter issue - Montana Owners Club

Starman · 10-12-2019, 03:25 PM

The hits just keep comin with lemonade. Can’t figure out why I keep popping fuses with my inverter. It only powers the fridge. I might go a week or 7 hours before one pops. Happens when hooked up to shore power. Any ideas.

PNW Fireguy · 10-12-2019, 04:27 PM

I am assuming since you specifically noted fuses that your issue is on the DC side. Check your wiring tightness, size and connectors for high resistance or poor connections.

Starman · 10-13-2019, 05:28 AM

Checked all wiring again.

Starman · 10-13-2019, 06:17 AM

Checking the DC connections would be for battery use correct? It was on shore power for a day when a fuse popped.
The inverter plugs into an outlet which I assume is from shore power.

PNW Fireguy · 10-13-2019, 08:04 AM

Ok let me back up a bit. Are we talking about blown fuses or tripped ac breakers?

Adding do you have a EMS like Progressive Industries? What I am getting at is do you have a means of checking incoming SP voltage? Voltage sag or low supply voltage can also be the issue.

jcurtis934 · 10-13-2019, 11:11 AM

You need to be clear about what is going on. When on shore power, you don't need to have the inverter on. The inverter inputs are 12vdc sourced through a breaker or high amp fuse of approx 150 amps. The output of the inverter should be going to a transfer switch unless the inverter as a built in transfer switch. The inverter output should be going to the fridge and maybe a couple of other circuits. What fuse is blowing?

Starman · 10-13-2019, 02:57 PM

The details...the residential fridge has no power if the inverter is not turned on. Battery or shore power. So I turn on inverter to power the fridge. The inverter has a 15 Amp fuse installed into the front next to the power on button. It screws out. That fuse keeps popping.
I’m stumped, help.
Am thinking I might have to buy a new inverter, possibly a 2000w. If I’m going to spend a few hundred on a new one, mine as well upgrade.

PNW Fireguy · 10-13-2019, 03:37 PM

By chance is there anything else plugged into the inverter? It should only be powering the dedicated fridge outlet. I believe it’s cord and plug connected.

Starman · 10-13-2019, 04:06 PM

Only the fridge. And yes it is plug n cord connected which run behind a wall I am about to take out. Follow the wire to the fridge. Maybe a ground in wire?

Starman · 10-13-2019, 04:07 PM

Fuses are $5 a piece.

PNW Fireguy · 10-13-2019, 06:37 PM

I don't think a ground wire is your issue. More probable a loose connection within one of the junction boxes for one of those cord connections. If however your shore power connection is routinely low this could result in higher current to meet the wattage need. (P=EI...if E does down then I must go up to keep the equation true)

The fact that you state the issue is sporadic leads me to doubt that the inverter is the issue as well. If you have the means to check voltage with a multimeter and current with a clamp-on ammeter you could at least rule these items out.

jcurtis934 · 10-13-2019, 07:16 PM

Wow. Shore power should be passed through the transfer switch, whether separate or built in to the inverter, when shore power is present since it should be the priority connection. This should be the case even with the inverter powered down. Your issue sounds like the inverter is your sole source of power to the fridge and you are running off of batteries. If you find a separate transfer switch behind the panel, it is not switching over to shore power. By chance, have you flipped the circuit breaker that feeds the inverter circuitry to hard off condition, ie force all the way down then back on? If the breaker wasn't supplying 120vac to the transfer switch, you would get this type of symptions. If your ac breaker is okay and there is no separate transfer switch, then the inverter transfer switch is bad.

Starman · 10-13-2019, 07:20 PM

Thanks for the ideas guys really. Heading home tomorrow. Will troubleshoot more. Thanks again for the help

Arkware · 10-14-2019, 06:33 AM

I think jcurtis has nailed it!
Check the AC breaker that 'should' feed the fridge. possibly a loose wire?

Starman · 10-14-2019, 07:38 AM

Checked and tight. Gonna figure this out, just need amazon to hurry up and send those fuses.

ChuckS · 10-14-2019, 08:38 AM

If your Montana has the WFCO inverter the 120VAC is auto sensed internally when shore power is connected thus bypassing the inverter...

However.. if you have the Magmun CWS1012 inverter then you should also have the separate transfer switch...

I’d be checking wiring on the transfer switch as well..

Manuals for Magnum in case you need...

Starman · 10-15-2019, 04:20 PM

I have the WFCO 1000w inverter. How do I get power to the fridge when hooked up to shore power?. I have nothing. How is the power bypassed to fridge? If I install a new fuse and turn on inverter, I will have power to fridge. I’m stumped folks.

**AZ Traveler** · 10-15-2019, 04:29 PM

Maybe its time to call a mobile tech or take your rig into the shop?

Starman · 10-15-2019, 04:40 PM

AZ traveler...NEVER!! I’m going to figure this out. It’s a challenge. I have fixed everything else not under warranty on this and I will figure this out too! This forum has helped me immensely...and thanks to all that have helped/posted their issues.

**Carl n Susan** · 10-15-2019, 05:30 PM

Quote:

Originally Posted by Starman

...I have the WFCO 1000w inverter...

What Model WFCO 1000W inverter do you have? Is it the WF-51110R or the WF-5100 by chance?

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