DC electrical system

[TM99]

I'm installing a new charger at the front near my batteries versus the old single stage factory charger at the back. Even though I have connected all the wires the same way as before at the batteries, the only way I get 12vdc power throughout is when I power up the old charger (which is intended to be removed). So, I am looking for some advice or at least a few simple old 12vdc wiring diagrams showing what wires go from back to front (that I can't see) to the rear circuits.

2001 class A Georgetown Windsong

[CHICKDOE]

check battery disconnect switch. you may have your batteries disconnected from the rest of the wiring. your new converter is close to the batteries and doesn't go through the disconnect switch

[TM99]

Originally Posted by CHICKDOE

check battery disconnect switch. you may have your batteries disconnected from the rest of the wiring. your new converter is close to the batteries and doesn't go through the disconnect switch

Thanks... But I installed a new disconnect switch while I was at it. Definitely working...

Just trying to figure out the wiring from the batteries to the rear dc circuits. The "hidden" stuff. In other words - Where do the wires go to, on old FR class A's, between the old converters in the back and the batteries and dc circuits?

It appears to me that there is a direct connection between the batteries and the DC fuses with the old converter T'd in. Therefore, disconnecting the old converter at the back and installing a new one at the front should work I would think...

[ScottBrownstein]

Generally the converter is wired directly to the DC fuse panel and from there to the disconnect switch and to the batteries. That is why, even with the batteries turned off with the disconnect switch, the coach will have power if the shore power is connected and the converter is running. I have always hated that design since you cannot charge the batteries without turning on the entire coach DC system. This is also bad for solar using the same wiring.

Your symptom sounds like there is no power to the DC panel through your new disconnect switch (did you take out the old one?) and the only way you get DC is by turning on your old converter. Your new converter will charge the batteries but no DC can get the panel.

I am going to "move my batteries" (electrically, that is) by installing a new 1 GA or 0 GA positive feed circuit, with 200 amp fuse, between the battery bank positive and my existing 70 amp converter in the rear power bay and a 1 foot ground from the converter to the chassis. My converter is fine, PD9270. This way my electrical bay stays as an electrical bay and my solar, converter and rear inverter all have a solid path to the batteries.

[cavie]

[QUOTE=TM99;1808627]Thanks... But I installed a new disconnect switch while I was at it. Definitely working...

Just trying to figure out the wiring from the batteries to the rear dc circuits. The "hidden" stuff. In other words - Where do the wires go to, on old FR class A's, between the old converters in the back and the batteries and dc circuits?

It appears to me that there is a direct connection between the batteries and the DC fuses with the old converter T'd in. Therefore, disconnecting the old converter at the back and installing a new one at the front should work I would think...[/QUOTE]

It will but you have to run all the individual wires for each circuit from the back to the new Converter location. Both AC and DC You need to install a J-box at the old location. It's done all the time in a house when you move the service location. I suggest two pvc conduits. One for AC one for DC. Why are you moving the converter?

[ScottBrownstein]

Let's think of this more simply. Say you attached an external battery charger to your house bank...people do it all the time. Nothing would have changed in the DC system.

You need to revisit what you did installing a "new" disconnect switch, that is where the problem is.

[cavie]

Originally Posted by ScottBrownstein

Let's think of this more simply. Say you attached an external battery charger to your house bank...people do it all the time. Nothing would have changed in the DC system.

You need to revisit what you did installing a "new" disconnect switch, that is where the problem is.

Sounds to me like the OP is calling a "converter" a "charger" and has intentions of removing the old "Converter"

[TM99]

Like Scott says, I think of it as adding a second charger - and then taking out the first one.

I moved it because the new one is an inverter /charger and I wanted it close to the batteries versus running long runs of heavy duty cable to the back. And I needed more space than the back electrical bay has.

[CHICKDOE]

you about a test? disconnect from shore power. measure dc voltage at the battery terminals and then at the 12 terminals on both the new and old converters. from what you say I think you will get voltage at the new converter and none at the old converter. but there should be a direct 12 volt run from the old converter to the batteries. is there an old disconnect switch in this line? how to you have two sets of battery cables (one from old converter, one from new converter) connected to the batteries? can you disconnect what you installed for the new converter, put it back the way it was, and get the old converter working? then reconnect your mods carefully and verify each connection? perhaps time to get a cup of coffee and draw out on paper what you are trying to accomplish.

[ScottBrownstein]

No, generally there is a direct line from the old converter to the DC power panel and then, from there, the DC goes through the disconnect switch and on to the batteries. Simply stated...the line from the panel to the batteries ain't getting there.

[rk06382]

Originally Posted by TM99

Like Scott says, I think of it as adding a second charger - and then taking out the first one.

I moved it because the new one is an inverter /charger and I wanted it close to the batteries versus running long runs of heavy duty cable to the back. And I needed more space than the back electrical bay has.

I just installed a new Samlex EVO-2212 Inverter/Charger in the bay next to the batteries. I am working out the bugs of the new system. The charger can go as high as 100 amps, too much for the 20 amp garage outlet I have at home.

I found out, I may want to leave the original Converter/Charger as a backup system. I can plug it direct into my 20 amp garage outlet. I will tie-wrap the cord to make it too short to plug in to the original outlet. I will also label on it.

My project thread: http://www.forestriverforums.com/for...er-158353.html

[TM99]

Agreed.. That is the simple facts... The power isn't getting from the batteries back to the DC circuits. The disconnect switch has been replaced but that is irrelevant at this stage. I am manually bypassing it for now.

And yes, the old box was a converter/charger while the new one is an inverter/ charger. Hence the reason to move it closer to the batteries.

[TM99]

Originally Posted by rk06382

I just installed a new Samlex EVO-2212 Inverter/Charger in the bay next to the batteries. I am working out the bugs of the new system. The charger can go as high as 100 amps, too much for the 20 amp garage outlet I have at home.

I found out, I may want to leave the original Converter/Charger as a backup system. I can plug it direct into my 20 amp garage outlet. I will tie-wrap the cord to make it too short to plug in to the original outlet. I will also label on it.

My project thread: http://www.forestriverforums.com/for...er-158353.html

I was willing to do that to... But the old converter/charger seems to need to be on to get the DC circuits working. Which nullifys the whole new process...

[ScottBrownstein]

Why did you "replace" the disconnect switch? Has nothing to do with your other changes. You can leave the converter there, just unplug it, but that won't solve your current problem. If bypassing the new disconnect works...we know where the problem is.

[rk06382]

Originally Posted by ScottBrownstein

No, generally there is a direct line from the old converter to the DC power panel and then, from there, the DC goes through the disconnect switch and on to the batteries. Simply stated...the line from the panel to the batteries ain't getting there.

There should also be a fuse or circuit breaker in the battery bay. I have a 50 AMP circuit breaker in my FR3 battery bay:

[TM99]

Originally Posted by ScottBrownstein

Why did you "replace" the disconnect switch? Has nothing to do with your other changes. You can leave the converter there, just unplug it, but that won't solve your current problem. If bypassing the new disconnect works...we know where the problem is.

I replaced the disconnect switch because it was 20 yrs old and rusted. I upgraded to a higher power charger, with inverter, and new batteries so I figured a new, higher current disconnect was warranted too. Bypassing the disconnect doesn't do anything different. It is working well itself.

I'll do some more testing tonight and come back in here with results.

[CHICKDOE]

read post #15! I could see a blown fuse since you upgraded to a higher power converter. the additional power could have blown the fuse that was sized for the original lower power converter. and of course, with a higher power converter, did you upgrade the 12 volt bus to higher capacity cables?


I don't know this but it sure could be the problem

[ScottBrownstein]

Originally Posted by rk06382

There should also be a fuse or circuit breaker in the battery bay. I have a 50 AMP circuit breaker in my FR3 battery bay:
Attachment 171788

Yep...good catch, there has to be a breaker between the batteries and the power panel. That could be the problem.

[TM99]

At this stage it is just 12vdc from the batteries I am trying to send to the DC circuits. I did upgrade cables between batteries and new inverter /charger because of the potential high power being pulled for AC inversion plus a big 400A catastrophic fuse. And I have dialed down the charging amps to 30A due to battery size - 217ah. (I think the previous charger was a 55A)

So... I'm back to wondering what cable am I missing from the DC circuits to the batteries. I reconnected three ~8ga and one ~4ga cables to the battery output (through the disconnect) but apparently I am missing something.

So... I will go back and look deeper and see where the DC circuit outputs go (assuming old charger goes there first like Scott says.

My only other guess at the moment is that the old converter has both a positive and ground connection while only positive wires are connected at the battery. Battery ground wires connect to the frame. I wonder if I am missing a ground somewhere.

[Skyliner]

Not sure what the problem is. Installing a new converter next to batteries is fairly easy except for running Romex if you are going to use the same 30 or 50 amp trailer connection point.

Converter output should be wired directly to battery at first to make sure i tis working and the circuit it is connected doesn't have a blown fuse.

Good luck with your issue and hope you sort it out. Be ware of some of the responses here. The person who told you that every DC line has to be re-routed to the front is trying to help but is ill-informed.

I find it very interesting about how electrical threads receive so much feedback from posters and it is easy to assume they know what they are talking about but when you search the poster's threads, you see that they take their RV's to the dealership for everything to include having the toilet paper changed and tire pressure checked instead of doing it themselves.