Panel seems to kill circuit

MikeinBigBend

I am using a Renogy 100 watt panel in an A-liner camper With a Wanderer control unit. The panel is charging the battery according to the control unit but the DC does not work in the camper (even though the control unit shows a charged battery.) The DC then works when I plug into the 7way trailer hitch. Makes no sense to me. 

BB.

Welcome to the forum Mike,

It sounds like you may have a blown fuse/breaker/broken wire/connection somewhere... Using a 12 volt test lamp can work better than a DMM (digital multi-meter)... The 12 volt lamp puts a load on the circuit and lights when the circuit is "live". This works well when trying to find a corroded/poor electrical connection... The poor connection may show up as "12 volts" with a DMM (DMMs typically take almost no current to read the voltage vs the 12 volt lamp).

The other "nice" piece of test gear to have is an AC+DC Current Clamp DMM. This allows you to measure the current (AC for 120 VAC wiring and DC Current for your DC Battery circuits). They are pretty reasonably priced these days:

https://www.amazon.com/gp/product/B00O1Q2HOQ (cheap/good enough meter for our needs)

https://www.amazon.com/gp/product/B019CY4FB4 (mid priced DMM)

Note that there are AC current only DMMs (good meters, just not useful for DC current measurements)--But the DMM part (voltage) is AC+DC VAC capable. So--If you get an AC+DC current clamp DMM--make sure it is AC+DC current capable.

Just pick a place to start--Disconnect the trailer plug, and start measuring/testing at the battery bank (12 VDC?), and follow the wiring to the fuse/breaker panel, etc.

-Bill

BB.

I should add a couple of other notes:

1) Always double check the +/- wires on the panels... Sometimes there are wired "backwards" (custom panels, mistakes, no connectors). If you put a panel "backwards", the "diodes" of the solar cells will be a short circuit. If connected directly to the battery bank (or a large array) backwards, it will blow fuses/breakers (if present) and probably smoke the panel.

2) When working with solar charge controllers... Always make battery to controller connections first, then connect (or disconnect) the solar array. If you connect the array first (in sunlight), it is possible to confuse the controller (boots incorrectly) and sometimes even fry the controller. If you have been playing with the charge controller, a) first disconnect the array and b) disconnect controller from battery bank--And reconnect (controller to battery bank first) after a few minutes of no-power.

-Bill

MikeinBigBend

Thanks Bill. Unfortunately, I am at Big Bend with my new trailer and solar panel and don’t have my volt meter or any testing device with me. The controller indicates that the panel is charging the battery with panel voltage between 13 and 22 volts and amps up to 3.0. I was pretty careful about + and - leads and did connect the battery first. Still a mystery to me. Thanks for your suggestions. When I can get my hands on a meter and a tester, I will start following the lines from battery to fuse box. Going to get cold tonight. 

BB.

You can get a simple (cheap) meter and test light from a local autoparts store or hardware store...

I don't think you reversed the panel connections. But you may have an open somewhere between the battery bank and the main DC panel (it sounds like).

Good luck,
-Bill

MikeinBigBend

Bill: I traced the power line from the battery to the fuse block/converter and found an inline fuse that was blown. Replaced the fuse and everything is running as it should. Thanks for your help. 

BB.

Very happy I could help Mike.

Have a great trip.

Bill