i recently bought a 30 foot bumper pull...the ac power works fine but i have no DC power from the 30 AMP WFCO power supply - converter - charger... i tested using a DC test light...20 volt ac power is going to the converter i do not plan to use batteries but i want to use the 12 volt lights, bath exhaust fan and vent-a-hood...can i use an inexpensive ac to dc converter and power it from the circuit that powers the current, non-working converter...if so, the current set up is 5 fused DC outputs, but only 4 are used and i haven't been able to find anything similar to use beside the current box....all only have single outputsdo i use inline fuses and run all 4 DC circuits from the single output on a converterhelp suggestions or ideas are welcome

My suggestion would be to put a battery in it. Then see if the converter charges it. Why no battery?

Inexpensive 120vac to 12vdc units generally do not have a battery charging control. You will risk cooking your battery if you decide to use one later. Get a good RV converter.

no batteries because it's going to be a somewhat permanent place for my dad to stay in...always connected to 120 powerthe 12 volt system should work while connected to AC power without a battery...right or wrong ?

i do not need a battery charger...if i had plans to use it as a travel trailer, i'd buy & replace the entire power box...i just would like to use the existing DC lights & fans rather than wiring for new AC lighting and vent fans

esty wrote:the 12 volt system should work while connected to AC power without a battery...right or wrong ?Sometimes right, so it's wise to have a battery.Your converter manual will tell you about that.

DC power not working | Good Sam Community

11 Replies

westend
Explorer
Jun 10, 2016
On the left side of the distribution panel are three screw lugs that have four wires attached to them--two red, two white. Two of those wires, a red and a white, are connected to the converter. Two of those wires are connected to the battery, one red, one white. If you're removing the converter from powering anything and substituting the power supply, remove the converter wires. Use the two power supply wires, one (+) phase, one (-) phase from the power supply and put those in the respective screw lugs you vacated.
esty
Explorer
Jun 10, 2016
westend wrote:
If I was using a power supply in a typical travel trailer, I would connect the output of the supply to the two studs on the trailer's 12 V distribution panel. The typical 12V distribution panel has a number of fuses for the different 12V devices that are powered.

I guess you have no plans to move this trailer on the road? There are laws about break away emergency braking systems but if you live in the bush, they may not matter.

thanks that's a very good solution to keep the different DC circuits fuse protected

you're correct, i live in the boonies and have no plans to ever have the trailer on the road

here's what i have...where would i connect a stand alone power supply to keep the fuse protection, using the built in fuse panel
westend
Explorer
Jun 10, 2016
If I was using a power supply in a typical travel trailer, I would connect the output of the supply to the two studs on the trailer's 12 V distribution panel. The typical 12V distribution panel has a number of fuses for the different 12V devices that are powered.

I guess you have no plans to move this trailer on the road? There are laws about break away emergency braking systems but if you live in the bush, they may not matter.
esty
Explorer
Jun 10, 2016
no battery will be used...if using a 12V (nominal) adjustable power supply how do i handle the different 12V circuits currently in the camper....attach an inline fuse to each line?
westend
Explorer
Jun 10, 2016
esty wrote:
2oldman wrote:
esty wrote:
the 12 volt system should work while connected to AC power without a battery...right or wrong ?
Sometimes right, so it's wise to have a battery.

Your converter manual will tell you about that.

providing the AC to DC converter is working as long as i'm plugged into 120 volt AC power shouldn't the 12 volt system always work without a battery

i understand i could lose 12V power if the converter charger fails

how do home converters work that power lights, such as under counter LEDs etc when no battery is present?
Not all converters will work well without a battery connected. All converters benefit from having a battery connected because it smooths the output.
Residential LED and halogen lighting operates from transformers or a switched power supply, often regulated.

The simplest, easiest thing for you to do is buy another battery and connect it. If your converter/power supply no longer provides 12 + V, you will have to make a decision on how to accomplish that. There are many 12V (nominal) adjustable power supplies available, should you choose not to charge the battery automatically.
esty
Explorer
Jun 10, 2016
2oldman wrote:
esty wrote:
the 12 volt system should work while connected to AC power without a battery...right or wrong ?
Sometimes right, so it's wise to have a battery.

Your converter manual will tell you about that.

providing the AC to DC converter is working as long as i'm plugged into 120 volt AC power shouldn't the 12 volt system always work without a battery

i understand i could lose 12V power if the converter charger fails

how do home converters work that power lights, such as under counter LEDs etc when no battery is present?
2oldman
Explorer II
Jun 10, 2016
esty wrote:
the 12 volt system should work while connected to AC power without a battery...right or wrong ?
Sometimes right, so it's wise to have a battery.

Your converter manual will tell you about that.
esty
Explorer
Jun 10, 2016
i do not need a battery charger...if i had plans to use it as a travel trailer, i'd buy & replace the entire power box...i just would like to use the existing DC lights & fans rather than wiring for new AC lighting and vent fans
esty
Explorer
Jun 10, 2016
no batteries because it's going to be a somewhat permanent place for my dad to stay in...always connected to 120 power

the 12 volt system should work while connected to AC power without a battery...right or wrong ?
garyemunson
Explorer II
Jun 10, 2016
Inexpensive 120vac to 12vdc units generally do not have a battery charging control. You will risk cooking your battery if you decide to use one later. Get a good RV converter.