power center replacement (couple questions)

[gonzo628]

So, I replaced my TM's power center Saturday night/Sunday morning. After spending all day/night and part of the next morning (until about 04:30) I was able to get it working but have a couple follow-on questions:

1) anyone with a 2006 3124 KB? As part of the replacement, I've attempted to replace the cables from the Power Center to my dual tongue-mounted 6v batteries (increasing the gauge to 8awg). Tracing out the wires shows they go from tongue/battery, along the outside of the frame (under the camper) and up (through the floor) to the lower fridge compartment where each is wirenutted with 2 other cables. From the powercenter, the 2 leads look to go down through the floor in the bathtub area, but I cannot find where they are run between the fridge compartment and the tub enclosure. Any insight?

2) My original powercenter looks to have two 30amp "main" fuses. the new one did not have fuse positions marked "main". Further, not wanting to mess things up, I've left the wire that was tied to "main" disconnected. my wife and kids are camping right now and do not appear to be lacking any service and so I am unsure what that wire was for. ideas?

3) New power center did not come with a 12v bus bar. I am not an electrician (nor do I play one on TV) and did not want to chance systems faliure that might arise from "sharing" the negative bus. to address, I took one of the terminal blocks out of the old power center and hooked up my 12v negative to that. Was this the right move?

[rickst29]

I'm not even sure what you mean by a new 'Power Center'. The normal ways of replacing WFCO parts is to leave the box and bus bars in place, replacing only the +12V distribution board (with all the fuses) or replacing only the Converter section at the bottom. Can you give me a part number, or take pictures?

If you replaced the whole box, there should be different 'bus bars' inside it:

1. A bus Bar for all white (current carrying neutral) 120v wires, connected to the WHITE wire of the 30A - 120V power cord.30A - 120V S
2. A separate bus bar, connecting green/yellow (safety ground) wires from 120V outlets, connecting to the Green wire of the 30A - 120V power cord.120
3. Another separate bus bar, connecting 12V "Ground" wires to the frame, battieres, and bargeman cord "ground wire". and batteries.

The 12V distribution board should have one big wire (black/red), going through a big fuse, coming in from the power converter. It should have another big wire (black/red), coming from the battery string. Those are your +12V power input legs, although the battery wire is bi-directional: when the battery is being charged by the Converter, 12V current flows "out" to the battery.

TM originally used only #10 wire from the batteries, with one fuse up front at the batteries (30A), plus this fuse on the power distribution board. For a lot of people with bigger wires and better batteries, these fuses are replaced. And for a lot of people, the nasty one-time fuse up at the batteries has been replaced by a 12V circuit breaker.

[rickst29]

(1) These wires are dual 12V grounding wires, even though the color is not white. They go through the floor and get clamped to the frame within in a small, black plastic "cover box" behind the sewer drain assembly. Up at the batteries, the WHITE battery ground wires end at a clamp into the frame. The frame is the 12V "Grounding Wire" among those 3 clamps. You might want to verify that all of those clamps are clean and very tight - your TM has a lot of years, and probably a lot of miles, to loosen the clamps and corrode the connections. You might also want to increase the wire size.

(2) With one wire disconnected, you are currently running off the battery OR the converter. You need both wires connected. The WFCO board designated "Main" connectors for the purpose of supporting large wire sizes in the clamps. If your new board can connect #8 "downstream" from any fuse, choose one of them for your new #8 wire, and put in a 40A fuse. (If your Converter is bigger than 40A, then you need a bigger fuse - even though the wire size is typically quite small.)

(3) For 12V DC connections, Bus Bar == Terminal Block, you did fine. Just make sure that the Terminal Block is connected to both of the "Grounding Wires" going to the frame (the wires in question 1).

[gonzo628]

Originally Posted by rickst29

(1) These wires are dual 12V grounding wires, even though the color is not white. They go through the floor and get clamped to the frame within in a small, black plastic "cover box" behind the sewer drain assembly. Up at the batteries, the WHITE battery ground wires end at a clamp into the frame. The frame is the 12V "Grounding Wire" among those 3 clamps. You might want to verify that all of those clamps are clean and very tight - your TM has a lot of years, and probably a lot of miles, to loosen the clamps and corrode the connections. You might also want to increase the wire size.

(2) With one wire disconnected, you are currently running off the battery OR the converter. You need both wires connected. The WFCO board designated "Main" connectors for the purpose of supporting large wire sizes in the clamps. If your new board can connect #8 "downstream" from any fuse, choose one of them for your new #8 wire, and put in a 40A fuse. (If your Converter is bigger than 40A, then you need a bigger fuse - even though the wire size is typically quite small.)

(3) For 12V DC connections, Bus Bar == Terminal Block, you did fine. Just make sure that the Terminal Block is connected to both of the "Grounding Wires" going to the frame (the wires in question 1).

I may need some clarification here. i think the one wire I did not hook up was on the Positive side of the dc plant previously). I have it marked main and it was in either position 1 or 2 of the old panel which were both labeled main). I thought, though it was quite late (err early) and I was exceedingly tired, that I had verified both with the inverter powered up (shore power connected) and battery disconnected, and the inverse (battery connected, shore power disconnected) that 12v was working... perhaps this is not correct, though.

Regarding #3, i don't think i have the bus bar (terminal block) tied to either frame or chassis ground... will need to double-check this.

[rickst29]

Originally Posted by gonzo628

I may need some clarification here. i think the one wire I did not hook up was on the Positive side of the dc plant previously). I have it marked main and it was in either position 1 or 2 of the old panel which were both labeled main). I thought, though it was quite late (err early) and I was exceedingly tired, that I had verified both with the inverter powered up (shore power connected) and battery disconnected, and the inverse (battery connected, shore power disconnected) that 12v was working... perhaps this is not correct, though.

Regarding #3, i don't think i have the bus bar (terminal block) tied to either frame or chassis ground... will need to double-check this.

If your 12V "frame ground" terminal block(s) include both of the #8 wires which TM put in there to connect the grounding lugs in the plastic protector (behind the exterior dump valve and pipes), you've got it. If you use more than one block, attach each block to one of those wires - and also attach the terminal blocks to each other.

[Bill]

Originally Posted by rickst29

... TM originally used only #10 wire from the batteries, with one fuse up front at the batteries (30A), plus this fuse on the power distribution board. ...

Just a quick thought for new owners. The 30-amp fuse is located at the battery location, which may be at the front of the trailer for models with tongue-mounted batteries, but is in the rear for trailers with a rear-mounted battery.


Bill

[gonzo628]

Originally Posted by rickst29

I'm not even sure what you mean by a new 'Power Center'. The normal ways of replacing WFCO parts is to leave the box and bus bars in place, replacing only the +12V distribution board (with all the fuses) or replacing only the Converter section at the bottom. Can you give me a part number, or take pictures?

If you replaced the whole box, there should be different 'bus bars' inside it:

1. A bus Bar for all white (current carrying neutral) 120v wires, connected to the WHITE wire of the 30A - 120V power cord.30A - 120V S
2. A separate bus bar, connecting green/yellow (safety ground) wires from 120V outlets, connecting to the Green wire of the 30A - 120V power cord.120
3. Another separate bus bar, connecting 12V "Ground" wires to the frame, battieres, and bargeman cord "ground wire". and batteries.

The 12V distribution board should have one big wire (black/red), going through a big fuse, coming in from the power converter. It should have another big wire (black/red), coming from the battery string. Those are your +12V power input legs, although the battery wire is bi-directional: when the battery is being charged by the Converter, 12V current flows "out" to the battery.

TM originally used only #10 wire from the batteries, with one fuse up front at the batteries (30A), plus this fuse on the power distribution board. For a lot of people with bigger wires and better batteries, these fuses are replaced. And for a lot of people, the nasty one-time fuse up at the batteries has been replaced by a 12V circuit breaker.

So, the power center (as you surmised) is the entire cabinet. Although I did not source it here, this is the unit I am talking about: https://www.adventurerv.net/powermax...r-p-82652.html.

I did this because the original converter (PowerMax PM3-MBA LK) I was sent would not fit in my American Industries cs6000xl. (it was too deep). There were bus bars (2) in it (Neutral and Ground) but they were on the AC side of the box and were tied to the AC inputs from the converter/charger. I will be the first to admit that I am not an electrician. So when I could not find information online regarding whether or not AC and DC could share the same negative bus, I opted to scavage one of the bus bars (terminal blocks) from the old power center.

The new Panel's DC distribution board had a red and a white 8awg wire that were IDed as battery. After that, it had 11 DC positive connections 3 of which were 10awg and 8 were 12 awg. There were ambiguously labled "positive DC input 1 - 11.

when I could not fish the power wires out of the Tub area (or determine the path they took to get to the lower fridge compartment, I opted to leave the 10Awg black and white wires there and, instead of buttsplicing/shrink-wrapping them together, I opted to buy a couple terminal blocks (similar to the butt-splice but without the crimp component) and mate the 8awg to the 10Awg wire. I insulated this connection by wrapping it (two layers) in electrical tape. I intend to fish that 10Awg out and replace with the stranded 8Awg, just not confident I can free this wire at the moment.

Regarding the circuit breaker, I'd not considered that... May have to replace my "maxi" fuse (that thing is comically large) but was necessary for the 8 awg wire. When I replace the Terminal connections (same time I replace the segment of 10Awg wire) I may have to install a fuse, though maintenance access will not be easy (that connection is behind the power center).

[rickst29]

Originally Posted by gonzo628

.... There were bus bars (2) in it (Neutral and Ground) but they were on the AC side of the box and were tied to the AC inputs from the converter/charger. I will be the first to admit that I am not an electrician. So when I could not find information online regarding whether or not AC and DC could share the same negative bus, I opted to scavenge one of the bus bars (terminal blocks) from the old power center.

And now you know - the 120V "current carrying neutral" must never, ever, have an electrical connection with DC frame ground.

Originally Posted by gonzo628

The new Panel's DC distribution board had a red and a white 8awg wire that were IDed as battery. After that, it had 11 DC positive connections 3 of which were 10awg and 8 were 12 awg. There were ambiguously labeled "positive DC input 1 - 11.

The White #8 needs to be connected (electrically) to both of the #8 TM frame grounding leads. (The ones which go through the floor near the tub faucet, into the protector box on the outside of the frame. In my 2619, they were black wires - the factory was too lazy to use the correct insulation color). That +12V Red lead joins with the TM #10 Black wire from Battery +. It is unique in deserving to have fuses (or circuit breakers) at both ends, because it is bi-directional and also slightly exposed along the underside of the TM.

Some people have replaced that wire, because they have good batteries and want to allow higher current. (My own Battery Connection consists of #4, and "exposed" segments underneath the TM floor are run within LiquidTite conduit. But I've got a Lithium Battery, it's capable of absorbing very high charge current.) If you connect to the current TM #10, you should use fuses or breakers of 30A maximum current. If you upgrade to #8, you can allow 40A.

Originally Posted by gonzo628

when I could not fish the power wires out of the Tub area (or determine the path they took to get to the lower fridge compartment, I opted to leave the 10Awg black and white wires there and, instead of buttsplicing/shrink-wrapping them together, I opted to buy a couple terminal blocks (similar to the butt-splice but without the crimp component) and mate the 8awg to the 10Awg wire. I insulated this connection by wrapping it (two layers) in electrical tape. I intend to fish that 10Awg out and replace with the stranded 8Awg, just not confident I can free this wire at the moment.

Hmmm. It might be held very tight within a zip-tied "bundle". If you can't get at the zip ties, it might be better to cut off and cap the old one and pull a new one.

Originally Posted by gonzo628

Regarding the circuit breaker, I'd not considered that... May have to replace my "maxi" fuse (that thing is comically large) but was necessary for the 8 awg wire. When I replace the Terminal connections (same time I replace the segment of 10Awg wire) I may have to install a fuse, though maintenance access will not be easy (that connection is behind the power center).

Maybe you can the screws and pull the load center away from the wall a bit, to get behind the +12VDC circuit board cable holes?