Hi guys,hoping the experienced gurus here might take a moment to give a newb a little time and expertise.just got used 2000 phoenix pop-up a few weeks ago (my 1st rv and 1st experience with DC) i do HVAC repairs for living so OK with AC.there is no info with the camper that tells me what size fuses it should have. not sure if the right sizes are in there now.problem i'm having is with the dometic Model RM2354 3 way, single door fridge. works great with 120 VAC and propane but if turned to 12v it blows a 5 amp fuse in the little breaker/fuse panel inside the camper (not outside). the furnace quits working also when that 5 amp fuse blows. lights are oki downloaded the manual and it lists a 3 amp control system fuse and 5 amp AC heater fuse in the power module. the 12 VDC heater is listed as 30 amp (in line blade fuse).VDC is all new to me, but it seems like a 5 amp is a little low.do i need to take to the local RV dealer and have them figure out what size fuses are supposed to be in the 5 fuse slots or is there an easy way to check amp draw (like i would with my amprobe on VAC.thanks for your consideration.Bob

"12 Volts DC ConnectionThis refrigerator model requires a continuous 12 volt DC supply to maintain the automatic energy system. The connection is made to the positive and negative terminals of the terminal block on back of the refrigerator."That doesn't sound like it's a 3-way..but, you did indicate it was. Most fridges are around 300w.

This presumably would be for the controls of the fridge, and there's a separate fuse or circuit breaker for the 12V heater power?10A might be reasonable for the fridge and furnace controls if they're the only things on the circuit. 5A is rather small and probably would blow if both were used simultaneously. Often the RV maker will put a little key to the fuses and their proper sizes in with the fuse panel or in other literature, at least if they're nice about things. Sometimes these lists/charts are a bit hard to decipher, though...particularly in regard to what circuit has what stuff on it.

I would try removing each fuse and use my meter probes, on the amp setting, to touch each side of the fuse holder. This should complete the circuit, allowing the appliance to run, and also tell you how much current each appliance is drawing.Of course, my Fluke only goes up to 10 amps, so if I had reason to believe it was more than that, I guess I would just keep putting progressively higher fuses - 10 amp, 15 amp, 20 amp, etc. until I found the first one that didn't blow.

12 volt fuse size in the refrigertor's fuses is 25 amps so the "House" fuese feeding it would need to be bigger (if you run that thing on 12 volts. SUGGESTION do not use 12 volt mode. Use only gas and electric in a PUP you do not have enough battery to run the fridge on 12 volts.(Fuse is from a Dometic owner's manual the heater is between300 and 400 watts and that means a 25 amp flash bulb. er fuse.

Your RM2354 fridge IS a 3-way ....120V AC element, Propane & 12V DC elementThe DC Power Supply to the terminal block in outside fridge compartment should be fed from the battery with a 30A in-line fuse close to battery . NOT from a Fuse in the DC Dist panel.The DC from terminal block also feds DC to circuit board and the 3A fuse on circuit board is protection for the DC controls, propane etcThe DC element is powered directly from the terminal block in outside compartment with a 30A in-line fuse before the DC power goes to the DC Element Relay---hence the reason the DC Power should come directly from battery,DC Dist Panel fuses are not set up for 30A fed.Normal amp draw for your DC element---150W/12.5AA 2-way fridge WOULD be powered from the DC Dist Panel via a 5a, 7.5A even 15A fuse....but not 3-ways.

what size fuses? | Good Sam Community

wa8yxm
Explorer III
Oct 07, 2018
12 volt fuse size in the refrigertor's fuses is 25 amps so the "House" fuese feeding it would need to be bigger (if you run that thing on 12 volts. SUGGESTION do not use 12 volt mode. Use only gas and electric in a PUP you do not have enough battery to run the fridge on 12 volts.

(Fuse is from a Dometic owner's manual the heater is between300 and 400 watts and that means a 25 amp flash bulb. er fuse.
Optimistic_Para
Explorer
Oct 07, 2018
I would try removing each fuse and use my meter probes, on the amp setting, to touch each side of the fuse holder. This should complete the circuit, allowing the appliance to run, and also tell you how much current each appliance is drawing.

Of course, my Fluke only goes up to 10 amps, so if I had reason to believe it was more than that, I guess I would just keep putting progressively higher fuses - 10 amp, 15 amp, 20 amp, etc. until I found the first one that didn't blow.
DrewE
Explorer II
Oct 07, 2018
This presumably would be for the controls of the fridge, and there's a separate fuse or circuit breaker for the 12V heater power?

10A might be reasonable for the fridge and furnace controls if they're the only things on the circuit. 5A is rather small and probably would blow if both were used simultaneously. Often the RV maker will put a little key to the fuses and their proper sizes in with the fuse panel or in other literature, at least if they're nice about things. Sometimes these lists/charts are a bit hard to decipher, though...particularly in regard to what circuit has what stuff on it.
2oldman
Explorer II
Oct 07, 2018
"12 Volts DC Connection
This refrigerator model requires a continuous 12 volt DC supply to maintain the automatic energy system. The connection is made to the positive and negative terminals of the terminal block on back of the refrigerator."

That doesn't sound like it's a 3-way..but, you did indicate it was. Most fridges are around 300w.

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