Wiring philosophy

[mtbguy]

After having issues with my old Univolt and fuse block I ordered new ones and problems are mostly sorted out now. I have looked at lots of the threads on this forum but can't seem to find my answer, even with using "search" function.

What is the most efficient way to wire the converter/fuse block/ battery interface. I have a new Iota 55 amp intelligent multi stage converter, five position fuse block, new battery in existing box. (1976 Argosy 26). I will have everything properly grounded and protected with fuses.

It seems the easiest way is the let the lines out of converter charge the battery, and have the battery run a positive lead to the fuse panel. I have looked at other install photos where people have run both positive leads from battery and converter to fuse block. Its seems the system would work either way. In my mind the first method seems simpler and means the battery would always be getting topped off by the charger when plugged in to shore power, but I am not an electrical engineer!

Thanks!

Rick

[Minno]

From an electrical connectivity point of view, it doesn't matter. If we call the positive terminals on the battery "B", the converter "C", and the fuse panel "F", connecting them C to B and B to F is the same as connecting them C to F and B to F, or C to F and C to B. The positive wire or wires will connect all 3 positive terminals together. What you do need to worry about is that the wire size (gauge) is big enough to handle the maximum load that be be placed on them. In your case, the max load would be 55 amps, which is the max output of the converter.

The same applies to the negative side as well, although the negative side will not connect to the fuse box.

Chris

[Wazbro]

I believe it would be better to connect the battery to a switch then the fuse box and the converter to the fuse box. This way you can easily disconnect the battery for storage and you can still use 12V with the converter while the battery is disconnected.

[Minno]

Before using the converter without a battery connected, make sure doing so will not harm the converter. Most, if not all, want the load of a battery to help regulate the 12 volt output.

chris

[DKB_SATX]

If you run the converter to the fuse block, and the battery lines to the same posts on the fuse block as the converter, then you can remove the battery while the converter continues to power the trailer systems (obviously taking care to prevent the positive cable from shorting to the body of the trailer in the process.) A modern Iota should run fine with or without a battery in the loop.

If you run converter-battery-fuse block, then you'd have to make temporary connections to allow the trailer systems to run off the converter if you have the battery out of the loop.

[Jammer]

Hi Rick

Many different ways and most of them work OK.

I ask little of the 12v wiring on my Cayo and so when I re-did it I more or less went point to point and didn't think too hard about busswork, or about fusing it so that outages would be isolated, or anything. The Cayo has an older-style converter that doesn't charge the battery, but instead switches the load from the battery to the converter, so the specifics differ.

The best way to wire stuff like this is to use copper busbar to connect the fuses or breakers, but it's a fiddly way to do things and perhaps not worth the trouble or expense. I'm a fan of fuses, especially for the battery leads, since there have been reports of automotive circuit breakers failing closed leading to fires.

You might want to consider adding a battery disconnect switch at some point.

[Wazbro]

Originally Posted by Minno

Before using the converter without a battery connected, make sure doing so will not harm the converter. Most, if not all, want the load of a battery to help regulate the 12 volt output.

chris

Your right I should have said with many modern converters, some older converters it's not a good idea to not have a battery in the system.

[mtbguy]

Thanks everyone for the responses. I used your advice and ran positive leads from both battery and converter to a common bus that had the fuses on it. Switched everything out to modern automotive fuses and the main lines are 6 gauge wire so should handle it ok.

The best thing is everything worked! This was a good opportunity to re-route everything when I have the bath apart and PEX install going on at same time.

Take care.


Rick