Troubles running off battery alone.

[byAndrewDavis]

I'm having troubles with my scamp operating off battery alone. When hooked up to 110 and going through the converter everything seems to work fine. I noticed that in the 12v distribution block the + lead that comes from the battery had a blown fuse. as soon as i put another on in, it blows.
can someone confirm that this lead is hooked up correctly? I would assume that it would attach at the same point of the block as the positive coming from the converter but would like for someone who knows to help confirm
(the red circled part is where the battery comes in)

[Biggie]

I could be wrong, but it appears as though you may be trying to feed your system through a single fuse from the battery. It that's the case, then the fuse would have to be big enough to carry current for the whole electrical system. I assume the empty slot in the circle is where the blown fuse is was located? If the red wire coming from the bottom is the inverter positive feed, then I agree that the positive battery feed wire that you circled should connect to the same point so it is in a parallel circuit. The battery can charged from the inverter and supply circuit positive when the inverter is inactive.

[byAndrewDavis]

Originally Posted by Biggie

I could be wrong, but it appears as though you may be trying to feed your system through a single fuse from the battery. It that's the case, then the fuse would have to be big enough to carry current for the whole electrical system. I assume the empty slot in the circle is where the blown fuse is was located? If the red wire coming from the bottom is the inverter positive feed, then I agree that the positive battery feed wire that you circled should connect to the same point so it is in a parallel circuit. The battery can charged from the inverter and supply circuit positive when the inverter is inactive.

Thanks for the response. I just picked this camper up last week and the previous owner wasn't too knowledgeable about how everything worked so I'm flying blind here. I'm thinking it was wired wrong too, except in the manual under 12v problems it mentions "the fuse under the front bunk or at the batter box is bad" could it possibly be wired correctly with just too small of a fuse?

[Biggie]

It's possible it could have been wired correctly but the way it looks the fuse that is blowing would have to be big enough to cover all the other circuits. It looks like the total of your other fuses is 60 amps. That a BIG fuse and I don't know if that style comes in that size. A 45 may cover it. An analogy would be to look at your home breaker cabinet. You may have a 150 amp main, but the total of the individual breakers is way more than that. You might try pulling all the other fuses, replacing the one that is blowing, then replacing the other fuses one at a time to check that respective function.
It is more likely it was wired incorrectly. The inverter should have internal overload protection in the event there is a problem with the battery or other circuits.
Good luck. We'll watch the thread to see how it goes.

[Joe MacDonald]

I think normally there would be a fuse inline in the battery lead probably about 60 amps or so, and then the battery lead would go to the same point as the charger lead.
Make sure the polarities are correct, or you will have a problem.
If nothing else is turned on, the fuse should not blow when you insert it.
There should be no draw when the lights etc. are turned off

Joe

[byAndrewDavis]

I replaced the fuse in the circled area with a 30 amp and the lights seem to work (havent tested the rest), although I dont like this setup.
I think i'll replace the inline fuse near the batter with a larger, and connect this lead directly into where the converter comes in.
thanks for the tips.

[Andy B]

Originally Posted by byAndrewDavis

I replaced the fuse in the circled area with a 30 amp and the lights seem to work (havent tested the rest), although I dont like this setup.
I think i'll replace the inline fuse near the batter with a larger, and connect this lead directly into where the converter comes in.
thanks for the tips.

Fuses are sized to protect the wires from to much current. If a fuse that is to large for the wires is used, the wires could over heat, melt the insulation, or even cause a fire. You should check the wire size to determine what fuse is the largest that you can use safely.

[cpaharley2008]

I think 30 amp is the max in our trailers and that is on the main line from the battery to the converter with 5,10,15,20 amp fuses leaving the converter. Like Andy said, do not put an incorrect size fuse.

[Carol H]

Under the Documents section of this form under Electrical you will find the wiring diagram for the Scamp.

[Donna D.]

Here's a direct link to the Scamp wiring diagram in the Document Center as referenced by Carol: Fiberglass RV - Document Center - WiringDiagram_Scamp

[kevin61]

Your battery feed (circled in red) looks to be 12 or 14 gauge wire. I'd first change this to at least 10 gauge or heavier wire.

This heavier battery positive line could then be attached to one end of a 30 amp circuit breaker ($5).

Bussman DC Circuit Breakers

Your heavier converter wire (large red wire coming in from bottom of photo) should be attached, in parallel with the battery wire at this same point on the "power in" side of the breaker.

From the other end of the circuit breaker run a 10 or 8 gauge wire to the point where the red converter wire is presently connected.

You now have converter power and battery power coming into your fuse block, protected by the 30 amp breaker.

You may also want to change the size of some of your fuses to better protect the circuit they are connected to. My guess is the previous owner inserted whatever he had available just to complete the circuit. Most of the 12 volt appliances in your trailer will not require the larger 15 and 25 amp fuses that I see in the photo. The exception being the fridge which probably requires a 20 amp. For example, if you follow that blue 15 amp fuse back and discover that it is simply supplying power to two 1157 car bulbs which draw about 1.5 amps each (3 amps total) then you would be better served to replace the 15 amp fuse with a 5 amp fuse. However, if that same circuit is supplying power to eight 1157 car bulbs (12 amps total) then the fuse size is correct. You should follow each line back to see what it is supplying power to and then size your fuse accordingly.

YouTube - Fuseblock Connections_0001.wmv

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[byAndrewDavis]

thanks for the advise, when i get back from our weekend trip I will see about putting a larger wire on, at the moment I do know that there are 4 possibly 5 bulbs being ran off that one 15 amp fuse.
I haven't got the fridge to work yet, been working on a new floor.
thanks again for everyone's advise!

[Carol H]

Originally Posted by byAndrewDavis

I haven't got the fridge to work yet, been working on a new floor.
thanks again for everyone's advise!

If you post whats up with the fridge I suspect a number of people can help you with that as well. You will find that they do not cool down fast so its hard to tell in the first couple of hours if it is in fact working. I usually start up mine the night before leaving and put a frozen jug of water in it to help it along. I put some water in the ice cube tray which I check in the morning to see if they have frozen so I know its actually working.

[byAndrewDavis]

Originally Posted by Carol H

If you post whats up with the fridge I suspect a number of people can help you with that as well. You will find that they do not cool down fast so its hard to tell in the first couple of hours if it is in fact working. I usually start up mine the night before leaving and put a frozen jug of water in it to help it along. I put some water in the ice cube tray which I check in the morning to see if they have frozen so I know its actually working.

You helped more than you know. I was too impatient, just had to let it sit for a while before i felt the freezer cooling down. It looks like I'm all ready to go!

[Carol H]

Glad to help Andrew - owners impatients is the most common problem with our little fridges! ;-)