Replacing ancient power converter

[1tenor]

I am doing a reno on an old motorhome (not my Keystone TT). It has an old Phillips 301 power converter in it which is no longer working properly. It has two 12v outputs, one for the 12v loads and one that connects to the battery to charge it, etc.

I purchased a new power converter but it has only a single 12v output. Can I use this or do I need an additional something or other or do I need to return it and get something else? Any advice is appreciated.

PS. The old converter still provides power for the loads, but it's no longer delivering power to the battery. Could I just use this new converter to charge the battery and leave the old one in place to power the loads? Seems a bit wasteful, but....

[mikec557]

Originally Posted by 1tenor

I am doing a reno on an old motorhome (not my Keystone TT). It has an old Phillips 301 power converter in it which is no longer working properly. It has two 12v outputs, one for the 12v loads and one that connects to the battery to charge it, etc.

I purchased a new power converter but it has only a single 12v output. Can I use this or do I need an additional something or other or do I need to return it and get something else? Any advice is appreciated.

PS. The old converter still provides power for the loads, but it's no longer delivering power to the battery. Could I just use this new converter to charge the battery and leave the old one in place to power the loads? Seems a bit wasteful, but....

Old being a relative term, I don't know how they wired old motorhomes. But in my previous 2018 5er, and now my 2020 TT, the converter charger had/has just one 12v output. It connects to the fuse panel side of the WFCO breaker/fuse panel. The battery cables also connect to the fuse panel side and that's how the batteries pick up the charge from the charger/converter. Look around your fuse panel and see if you can wire it the same way. Look for a hole in the buss bar you can clamp down a 6ga wire. At least that's the wire size Keystone and Grand Design used on our last two rigs.

[1tenor]

Ancient in this case is 1974. I have learned that the old converter had a relay inside it that switched the power so that when there was no AC power to the converter, it connected the power from the battery to the load tap. When AC power is present, it separated the battery from the loads and ran the loads straight off the converter and charged the battery through that separate tap. I'm going to look for an external relay I can wire the same way, if I can find it.

[gearhead]

Maybe call bestconverters.com

[1tenor]

All done. I swapped out the converter and just wired the battery and the loads together at the converter. Battery is charging properly, 12v system is operating properly too. All is well.

[mikec557]

Originally Posted by 1tenor

All done. I swapped out the converter and just wired the battery and the loads together at the converter. Battery is charging properly, 12v system is operating properly too. All is well.

Glad to hear it. Sounds like how the modern RV is wired today.

[skids]

I just went through a lot of studying as I am refurbishing a 70’s vintage camper (Leyton?) The converter was trash. The fuse panel has only 3 fuses. Money was saved by the manufacturer by connecting positives (like 4 into 1) and (again 4 into 1) with the single wire going to the fuse panel. The negatives where connected the same way. Any protection with fuses to appliances needs to have wires isolated for the positive wires. The converter had a transfer switch to charge the battery. (weird) So, I got a Powermax 35 amp 12v output. It appears to have a good battery charger. I also got a good-looking fuse panel. I am still working through the rats nest of wiring.

[hankpage]

Many old RV systems only had one (fairly) clean circuit for tv and radio. Other circuits would give a terrible hum if not filtered with a trap or through the battery.