Electrical Troubleshooting...God I hate these questions!

[Team118]

Hello;
I typically cruise this forum and try to add my 2 cents or pictures whenever needed, but usually there are others more qualified than myself who answer.
I have a 1977 C-30 which I rewired 6-7 years ago. With a LOT of help from this forum and posters such as Stu. I have had no problems at all, periodically checking connections and cleaning as needed.

My system consists of 2 banks. One 12v battery in the engine bay that is only for emergency, I never use it. It is hooked to a 2 bank Xantrex 30amp charger.

The second bank is 4 T-105 6v batteries in parallel/series. This is the bank that I use for running the boat and starting it.

I always disconnect everything each winter and each summer I top off the batteries with disitilled water and I rotate the 4 T-105's around in their box.

For whatever reason, my bilge still collects water during the winter, so I normally connect the reserve battery, because it's easier to run the bilge pumps.

This is where I think I screwed the pooch. I wasn't paying attention, I believe I created a short when I hooked up the reserve battery. There are 3 cables to this bank, the positive to the Switch on the Panel, the positive to the Xantrex charger and the neutral to a neutral bus bar that ultimately grounds to the engine. However I connected these cables, the bilge worked but I believe I may have connected the charger cable to the negative side...

When I went to connect all of the cables in the other bank I did what I normally do which is connect them in a parallel series.

When I went to connect the cable from the alternator (which is only connected to the house bank for charging) it arced something fierce. The radio which was playing quit immediately.

I turned the switch to off and tripped the 100amp circuit on the panel. I tried reconnecting everything again. No sparks.

When I turned the switch back to the house and hit the 100amp breaker, nothing would work. If I switched to the reserve, the bilge pumps would work, but not the radio ( I may have blown the inline fuse, which I'll check later). I then started troubleshooting wires, checking continuity, connections. All of a sudden I started to smell eggs and I could hear the water bubbling in the batteries. I shut everything down and disconnected all the wires in the bank. It was then that I also discovered that I had NOT hooked up the reserve bank correctly. I disconnect that too.

I then reconnected the house bank but nothing is working. My meter says that all of the wires are fine, when the breaker is set there is continuity throughout the circuit. The batteries read about 12volts on the multimeter. None of the breakers tripped. All of the neutrals are connected correctly and have continuity.

I am lost as to what I am missing. Please note that the cable going from the Battery Switch to the Reserve Battery Bank is Black. I ran out of red cable and had plenty of black. It is flagged on the Reserve side. The Xantrex cable is also black to the reserve. Yes, this is EXACTLY why I am in trouble. I will switch these out this year. At the time, I didn't have any more money in the budget and I had the extra black laying around.

Any suggestions, or any more information you need, please let me know.

Thanks in advance.
Chris

 

[jeepbluetj]

In the 12v DC wiring, I assume you mean neutral to be negative (or ground). It seems to me that you connected something backwards and thus shorted 12v+ directly to 12v-. Big sparks, blown fuses, etc...

Disconnect everything and trace the wiring with an ohmmmeter.

You may have damaged more than just a fuse/breaker. No way to really know unless you trace all the circuits out and see what really happened.

 

[jssailem]

Chris I need to reread your post as I was having trouble following all the steps.

But when I had a black cable used by the PO to power the D.C. Panel. I put a 6 inch piece of red heat shrink on the cable to remind me it is a positive cable, till I can do a complete rewire.

 

[LeslieTroyer]

I can't say why you popped - those batteries look like they are connected correctly - but I do see 2 problems
1) I assume the yellow fob is the battery temp - It is in the wrong place - it needs to be at zero volts - you have it at a +6V from ground - it should go on one of the bottom battery connection as shown in the picture.
2) the AC portion of your panel needs a cover - the blue sea cover is very pricey - I've heard some folks raid the wife's tupperware for a cover. also you should route the DC panel source so it is not interlaced with the AC (which would happen naturally if you had the cover)

Now to the rest of your problem - you probably fried the 100A breaker and I would take the alternator to a shop to have it checked out. you can check the breaker by checking the voltage on both sides of the CB with it off - you should have 12 on the input and nothing on the other side, turn it on - and you should have power on both sides.

Hopefully this will emphasize what I hear Maine Sail preaching - put fuses on your batteries!!!! I just did a bunch of work when I installed my new charger, and MRBF's were high on my list - 250A - which goes to a distribution area that feeds my starter switches (not A,B,both) (no additional fuses) then ANL fuses for main DC Panel (120A), 2 ea ANL for ACR's (normal start battery & windlass battery), 60A ANL for my Charger, 30A MRBF for my 24x7 fuses (bilge pumps, VSM...) and a 120A CB for my Alternator

 

[kloudie1]

The red wire in the middle picture underneath the words "To Xantrrex" is tapping off at 6 volts .. if ya want 12 on that wire, it needs to go on the far right positive terminal .. radio may be on 6V and that is why its not working? and the charger may be pushing 12 into a 6V.. ??
Love the "Washer/Dryer" label on the AC panel..

 

[LeslieTroyer]

good catch Claude -
one other thing I saw when glancing back thru - and it is a personal thing I have - I've had problems with spade connections comping loose (especially if over current) -- It looks like you have 14 coming off your AB switch up to the bilge pump and spare. 1) there is no fuse on this line and it is at the top of its rating (15+15) for 10% and over on 3%. I hate to harp - but no fuse when dropping wire size it should be done behind a fuse or CB. you could hang a MRBF off of there put a 30A fuse on it with a 10 or 12 gauge wire - and be safe... I probably wouldn't have said anything if it terminated in a ring - cause they tend to stay put, while spade's can fall off and start shorting.

Les

 

[Stu Jackson]

Chris, Sorry to hear about your issues.

Do you have a wiring diagram? You may have heard me mention many times in the past that photos of wiring without a wiring diagram are useless to help anyone. In spite of that kloudie caught a good one!

Although after the horse left the barn, a wiring diagram would help you avoid this kinda issue.

I find doing wiring continuity checks are among the very last things I ever do or have to do. Rarely do the wires fry, so I check the connections and voltages first.

Good luck.

 

[Jongleur]

Red electrical tape wrapped the length of
the black wire would help and is pretty
inexpensive.

 

[Team118]

Stu

Here is the schematic I did when I originally installed the new wiring. The only difference is that the house bank is now 4 6v batteries instead of 2 12v's.

I feel now after some sleep that I definitely connected the positive lead to the reserve battery to the positive post and the positive lead from the Xantrex charger to the negative post. I think that since it was the only source of power to the system it still worked? Perhaps reversed things but didn't affect the operation of the bilge pump or the radio.

It looks as if putting the Xantrex positive lead to the negative bus was ok because it still found it's way to the main negative bus and completed the circuit but adding the 2nd bank AND then connecting the alternator caused the shortage.

Les Troyer mentioned putting fuses at the batteries and I can do that, none of the connections behind the panel are spade, they are all ring unless they are part of the original Blue Sea setup. All the wiring I did was with rings. He also mentioned that I may have blown the 100amp main circuit breaker. I will say that I tested it for continuity (not volts). If the circuit was tripped, there was no continuity, but I turned the breaker on, there was flow. To test for volts, I assume I would put one sensor on one end of the breaker and the other to the negative bar?

Finally, I never thought about the Xantrex charger being connected to 'a wrong' position. I did that because there were 4 connections on the one positive post: the connection to the battery switch, the alternator, the Xantrex positive and the cable to tie the battery into the series. The post about the Xantrex temp sensor being wrong, it is on the negative post of the battery that contains all the 'outgoing' positive cables mentioned above, I thought the manual said it has to be on a negative post.


Thanks!
Chris

 

[kloudie1]

Chris, the inter-battery posts are at 6 volts and not 12 .. so the temp sensor is at 6V .. it should be on either of the foreground (center picture) negative terminals, but not the middle .. same with the red wire under "To Xantrex".. as I mentioned it is at 6 volts and not 12.. it should be on the positive marked "To Battery Switch"

 

[LeslieTroyer]

Battery temp is at 6 volts. Yes it is a negative post but at elevated potential. You need it at ground or zero volts. You need to treat these + to - connects as don't connect anything to them.

I misspoke using word spade I ment the quick connect push on terminals. You have them on the bilge pump and spare. The one with 2 wires looks as if it was never heat shrunk. I don't know what ABYC thinks of two wires in one connector. These may be from Blue Sea that way. Again I said it is a personal bias that I don't care for this type of connection unless it is carrying very low amps. 15A in my not so humble opinion is too much, which can cause them to get hot and loose grip in its mate which will cause it to get hotter.....

On all screw/bolt down connection the biggest wire goes down first, smallest on top. On your main house breaker it is reversed ( this is minor and should be way down on you priority list)

 

[Team118]

Thanks Claude, I understand that now. That makes sense as I was checking voltage yesterday and it would read 6v between individual batteries but 12+ v as you say from the negative on one end to the positive on the very opposite end.

Thanks!

 

[Team118]

I will correct the bilge setup and adjust the sequence of hook ups.

Thanks
Chris

 

[kloudie1]

Good luck with it, Chris.. Hoping that all is good and the fuses/circuit breakers stopped any real damage..

 

[Team118]

UPDATE
I like closing threads, so here is the final outcome.

Pilot error...many times over.

ERROR ONE
I hooked the positive line that charges the reserve battery bank to the negative post. That is because the cable is black and I didn't look at it. I hooked it up quickly, I did it without looking at the cables because I was in a hurry. I can only assume doing so still completed the circuit and allowed the bilge pump and radio to work.

ERROR TWO
Every year I rotate the four 6v batteries. Like that little game where you have to move the numbers around in the plastic tray to get them in order. I pull the bottom right battery out, pull the back one forward, the back left over..etc. This year I took them all out to check their water levels and top them off.

When I put them back in....the back two were reversed. The negative posts were in the back and the positive posts were in the front. The front two were a mirror image of the back two:

(-) (-)
(+) (+)

(+) (+)
(-) (-)

So, I connected the back 2 negative posts, the front 2 negative posts together and then I connected the middle positive posts together. Looked good in a picture.

When I connected the alternator to the negative post in the back...boom!

I realized I hooked the reserve wrong and reconnected it.

I didn't figure out what was wrong with the house back until I kept testing voltage. I was getting nothing across the two sets of batteries. I would only get voltage off the front 2.

I load tested the batteries and there was absolutely no damage, I blew 2 fuses in the radio which I replaced. Everything is now working perfectly.

I want to thank everyone for their thoughts!
I will put little red paint dots on the battery to easily see that, I will wrap all positive cables with red electrical tape, I will readjust the connections in the back, I have a Tupperware dish to cover the AC panel and I will put fuses on both battery banks.

THANK YOU AGAIN!
Chris