Fridge issue

[Salty]

The heating element runs off 12VDC. There is a control board that has a an AC/DC converter on it. The control boards I've seen seem to use a transformerless switching converter. Personally, I am not a fan of switch mode power supplies, but they have improved over time (most laptop bricks and desktop power supplies are switch mode supplies.)
So, if the fridge runs off Direct DC but not AC, the control board is the likely culprit. This is not to say that your heating element is not bad since it's resistance measured low.
Interesting video here:
https://www.youtube.com/watch?v=b2zioJ7XwmM

[Rostam]

Sounds good. However, I wonder what was causing your breaker to trip (or was it a gfci?)? I don't know much about these fridges, but what's different about the heating element if on 12v or 110v? I wonder if something else with the 110v might be causing the breaker to trip? Was it the breaker in the house, or the breaker at the 30 amp panel in the trailer?

Its the breaker at the 30 amp panel in trailer. My theory is that the AC heating element's lowered resistance causes the amperage to increase and trip the circuit breaker.

Unfortunately, my DC experiment ran into an issue. I checked the fridge at night and noticed that my wine bottle was not cool. The battery was drained, so it seems the fridge running on DC consumes more power than the converter can produce. I have only one battery though, so maybe adding another battery in parallel solves the problem? Need to find out the amperage of the fridge running on DC.

[Salty]

[/quote]
Its the breaker at the 30 amp panel in trailer. My theory is that the AC heating element's lowered resistance causes the amperage to increase and trip the circuit breaker.

Unfortunately, my DC experiment ran into an issue. I checked the fridge at night and noticed that my wine bottle was not cool. The battery was drained, so it seems the fridge running on DC consumes more power than the converter can produce. I have only one battery though, so maybe adding another battery in parallel solves the problem? Need to find out the amperage of the fridge running on DC.
[/quote]

OK, now you introduced another variable, but I think you can figure this one out pretty quick.First, determine how much current on 12VDC the fridge is supposed to consume normally - owners manual specs. Charge your battery, and turn on the fridge. Measure how much current it is consuming. Personally, I believe it is the heater element, based on the battery draining so quickly. But then you may have two issues (Battery and fridge) and not just one.

[Rostam]

Its the breaker at the 30 amp panel in trailer. My theory is that the AC heating element's lowered resistance causes the amperage to increase and trip the circuit breaker.

Unfortunately, my DC experiment ran into an issue. I checked the fridge at night and noticed that my wine bottle was not cool. The battery was drained, so it seems the fridge running on DC consumes more power than the converter can produce. I have only one battery though, so maybe adding another battery in parallel solves the problem? Need to find out the amperage of the fridge running on DC.
[/quote]

OK, now you introduced another variable, but I think you can figure this one out pretty quick.First, determine how much current on 12VDC the fridge is supposed to consume normally - owners manual specs. Charge your battery, and turn on the fridge. Measure how much current it is consuming. Personally, I believe it is the heater element, based on the battery draining so quickly. But then you may have two issues (Battery and fridge) and not just one.
[/quote]

Thanks Salty! I did look up the fridge's DC amperage: Its 23 amps per fridge manual (Seems high to me). I also read the electrical systems section of trailer's user manual and apparently when connected to shore power a transfer relay switches the electrical systems from battery power to outside power (I was not aware of this). My question is if how did my battery get drained? Maybe the relay does not work?

[Salty]

I think you may be getting off track here. Stick with the fridge. for a test, you don't have to power the fridge long. a couple of 10 gauge jumper wires to a 12V battery will suffice for the current measurement.
Alternative. Plug the fridge into an extension cord connected to your house and check the current (clamp on ammeter required)
A few things of note.
The entire cooling section can be changed, I believe.
The heater element can be changed as well.

[silverloaf]

KY -
A 250A fuse for 8 gauge wire seems way over the top based upon ampacity charts I've read. Am I missing something here?

Also, I've heard it is not good practice (or code required) to plug a fridge into a GFCI-controlled circuit. Apparently, the fridge circuitry can send rogue ground signals to the GFCI and trip it. The solution is to either run a separate circuit for the fridge or install the GFCI in the circuit after the fridge.

[Salty]

I missed something. 250 Amp fuse? 8 gauge wire?
Did I miss a post?

[silverloaf]

I missed something. 250 Amp fuse? 8 gauge wire?
Did I miss a post?

Go back to KY’s post here on 6/27 at 8:43pm

[Salty]

right, got it.
250 amps fuse on the DC side of the inverter and 8 gauge wire on the 120VAC side?

[KYAvion]

I am so sorry for the bad info I posted. It's been awhile since I did this. Thanks for catching that! With the inverter I was using, which was a 1,000 watt modified sine, a 150 amp fuse and 4 AWG for the pos and neg from the battery (8 AWG for ground) is appropriate. This is all on the DC side. Wires runs should be as short as possible, or else the wire size should be increased to account for voltage drop. If using the inverter ONLY for the fridge, then the wiring and fuse could be downsized and/or the length of wire run could be longer.

The fridge plugged directly into a receptacle on the inverter, so I just plugged and unplugged from 110 to the inverter when traveling.

As far as the GFCI issue, I've read that concern as well. However, I never had an issue. In fact, when parked temporarily for a couple weeks at a time at home, I always had my trailer plugged into an outside GFCI.

Also, I'm no electrician. I'm just sharing what worked for me.