Debugging shore power issues (12V fine)

winetab

We have our T@B plugged in between trips, however, after our last trip I found out the shore power no longer seems to be working.  It definitely was before, and I need some help debugging what appears to be an issue in the power converter.  (wfco 8735).

I found out the shore power wasn't working as our battery completely discharged the following week while I thought the t@b was getting a nice charge.  Checked all the fuses as I assumed that was it, then noticed no 120V power.

Steps I've taken to debug so far: verified 120V at trailer entry.  Verified 120V incoming to the converter.  Verified 0V out from the converter (I had replaced the GFIC as well, just in case).

When I first apply power, the fan on the converter will start up for about 3-4 seconds then turn off.  No power to outlets A/C etc.  Help!  I have put the battery on a tender to keep it alive while I try to figure this out.

Help much appreciated!  Brett.

Verna

What year of T@B, please? That will help us to know what components are in the T@B. 

winetab

It is a 2015 T@B S M@x.  Thanks!

RollingBnB

So no 120v OR 12v from convertor, sounds like main breaker is tripped.

ChanW

Is the GFCI breaker tripped, on the outlet near the breaker box?

winetab

Correct, no 120V or 12V from the converter.  I would think it is totally dead except for the fact the fan starts up for a few seconds when power is first supplied to it.

Verified the main breaker is on (have flipped it on and off).  For the GFCI outlet it isn't set, but can only be reset if there is power once tripped.  I thought it might be the issue so I actually replaced it early on and still no dice.

Sharon_is_SAM

Verna, wasn't there a bad batch of converters out there?  Was it 2015?

ScottG

@winetab, the 120V distribution system is pretty simple. It works just like that in a typical house--most problems can be traced to a broken connection somewhere.

From your description and preliminary tests, it sounds like the problem lies in the 120V breaker panel. The converter itself (the part of the box that changes 120V to 12V) may be perfectly fine, but with no 120V in you get no 12V out. (Most of the T@B's devices run on 12V.)

There's not much to a breaker panel. A loose connection on the main breaker would be the prime suspect. Ruling that out, a faulty main breaker would be the next most likely culprit.

A tripped GFCI receptacle would cut power to the regular cabin outlets, but the A/C, fridge, and Alde outlets have dedicated circuits that would not be affected by this. If you don't have power to any of those devices, that further points to the main breaker.

Just like in your house, you (or someone comfortable with such work) should be able to take the front off the breaker panel to inspect the connections or, if necessary, swap out the main breaker. (Obviously, you should do this with the shore power DISCONNECTED!)

Verna

@SAM, the bad converters were of the Elixir name brand and were the smaller models used in the early 2011/12 or so of the Little Guy teardrops. That brand has been out of business for at least 5 years. nüCamp uses the WFCO brand now. 

Michigan_Mike

It is a 2015 T@B S M@x.  Thanks!

I agree with Scott as you need to eliminate the incoming power source as overheating wire via poor connectivity can create issues.

If it were me I would also start at the side of the trailer, pull the receptacle out, inspect/tighten all the lugs and do the same inside the bench area where the wiring enters the converter.  Wiring can heat up and shrink via heating over time and a loose lug can create issues too.  

Tighten down all the lugs on the grounding block in the bench area, pull the face cover off the converter, tighten down all the lugs and connections in the converter and inspect the home power source receptacle too.  

You may in fact have a bad converter but eliminating the connections is a start and ensuring the power cord prongs are solid and (things like that) you are getting good/consistent voltage into the trailer 

winetab

Thanks!  Had time this weekend to work my way in from the outside.  Power connections are tight and conducting through to the circuit breakers (replaced the main one, just in case).  Traced the power that is supposed to get to the outlet to the board connection where it is still 120V.  Looks like something is either dead with the power converter board, or there is something loose in there.  I'll try taking off the back of the power converter and checking all the connections on that side when I get a chance next.  May be that the converter has given up the ghost :(  Fingers crossed the rear outgoing connections show something more.