Electrical issues

[Libbitt]

I've been doing some basic remodeling on my Safari. Before I shoved back in the couch, I thought I'd upgrade the converter. I got a Boondocker 60 amp and set it up. Reattached all wires- pos, neg, ground, neg. battery wires. Plugged it in in both places, converter to wall, trailer to shore power. The Boondocker didn't seem to work, although it did warm up and briefly the fan came on. No lights, no control center lights. The person I bought the new Boondocker from kindly tried to help. He noticed from a photo I sent that I had the pos and neg wires on the converter switched. I fixed that. Now the negative black wires on he battery spark whenever you try to connect them. So... I put the original converter back in. Same sparking.
What is going on?
I haven't even able to go camping yet and have the Blackout Rally coming up.
Help!

[uncle_bob]

Hi

First off, getting across electricity can kill you. Be very careful doing this stuff. You will need a multimeter to figure out what's going on. If you don't have one head over to Home Depot and get a $20 one.

1) Measure the battery with nothing attached? Is it around 12.6V? If not it needs a charge. The converter will try to do that when it's hooked up.

2) Measure the 120V headed towards the converter without the converter in place. It should be 120. If not figure out where the juice stops and fix that.

3) With the 120V shut off wire the converter to the AC. Don't hook up the load side yet. Make sure that ground goes to ground, hot goes to hot, and neutral goes to neutral.

4) Power up the converter. Measure the output of the converter with nothing on the output. It should be in the 13.5 to 14V range. If its under 12 or over 15, it's broke. Send it back. Check for lights with nothing attached. No lights probably means it's broke.

5) Shut down the AC and wire the converter to the battery. Positive goes first. Negative goes second. Charging up the output capacitor will give you a small spark. There should be no major blasts.

6) Power up the converter. Measure the battery voltage. It should be up above 13V unless the batteries are very dead. You should get lights on the charger. If this all isn't true, the converter is broke.

Powering stuff like this up with the wires reversed is not recommended. You may have blown the converter. If you ran things backwards for a while the batteries may not be very happy at all. How much went wrong depends a *lot* on exactly how the internals of your specific model are designed.

Bob

[Libbitt]

Yep, husband says we did all that.

[uncle_bob]

Originally Posted by Libbitt

Yep, husband says we did all that.

Hi

Ok, what is the voltage on the battery with no converter and with the converter running?

Bob

[TG Twinkie]

If you connected the converter incorrectly. You probably have blown the reverse polarity fuses on the converter itself.
Look for to large fuses on the back. 40 amps plus in size. If they are blown the converter will not function.
You should not be connecting the battery cables with the converter powered.
With the converter powered DOWN connect the battery cables. If you draw an ark you may have some DC device turned on which causes the arc.
YOU MUST BE ABSOLUTELY SURE THE BATTERY, THE HOUSE CONNECTIONS AND THE CONVERTER ARE CONNECTED WITH THE CORRECT POLARITY.

[Libbitt]

The rv repairman said one should never turn off the converter. Is this true?

[TG Twinkie]

So he is saying "never remove AC power from your RV"?
What is his reasoning?
Basic electrical safety rules are NOT TO CONNECT ANY DEVICE WITH POWER APPLIED.
There for the converter should be powered down when connecting batteries. As well as any device(s) known to be on.
Some devices like smoke detectors, CO and propane detectors are hard wired. Which makes it difficult to power down these devices other than pulling fuses.

[Al and Missy]

The converters have large capacitors in them. When powered off, they will discharge. When you connect them to a battery, they will most likely generate a spark. You may have nothing wrong.

If you measured something around 13 volts coming out of the converter and something around 12-13 volts on the batteries and you connect the wire that was positive from the battery to the post that was positive on the converter, everything should be fine.

To be really safe, you could get a large inline fuse 30 amps or so and put it in line between the converter and the battery temporarily when you connect everything up. If everything is OK and the fuse doesn't blow, take it out.

As noted above, the Boondocker family has reverse polarity fuses. Check them and replace as required.

A final note. Connect the batteries with the converter unplugged.

Al