Low voltage warning

[Lou39]

2008 Rockwood 26' 5th wheel with 30amp service. Hi,brand new to forum but have lurked for years.
Here's my problem;  Low voltage issues; warning light and beeper on, no 12 volt systems work, slides, jack, etc. House Battery good 13.2v, and load tested good. Everything works when plugged into truck tho. Full disclosure, rig was used as a extra bed room at a cottage and they left the air on for 5 days I'm told. It was plugged into a 110v 15A circuit and the adapter was melted.
Everything worked OK when I retrieved it tho, and the problem arose a few days later when wife wanted to cool down an ailing dog. The rig was plugged into a 110 15A  at home like we have done for years and rarely used the air at home. The control panel is WF8955 AN, all fuses checked good with 12.6v to both sides, all grounds retightened, wires visually checked, panels pulled in basement and all looks good.
Any help would be appreciated.
Regards,
Lou

 

[grashley]

Welcome to the Forum!

Please provide a bit more information.
What low voltage alarm?  Where is it located?
I assume this is plugged in at your house.  Is it connected to a 30A 120V receptacle or a 15 / 20A with an adapter?
How long an extension cord  are you using?  What gauge?

A 16 gauge cord will not carry the needed current.
A 14 gauge may be good for 25 ft.
Anything over 25 ft really needs a 12 gauge cord.

It is a bit like trying to pump 10 gal/min through a ? inch garden hose.  Not gonna happen!  Try a 1 inch hose, and now it works.

 

[Gary RV_Wizard]

Your house battery numbers seem OK, and the voltage at the fuses is adequate if not great. So, what is this alarm you speak of?  And warning light?

You say that nothing 12v works, yet there is voltage at the fuses in the distribution panel.  You seem to know your way around electricity, so can you trace the power further down the lines until it disappears. And verify the chassis ground side as well.  Are you measuring voltage to chassis ground, or direct to battery?

What "panels pulled in basement"?  Basement of what, and what panels?

You mentioned 120v/15A usage a couple times, but the problems cited are all 12v system. Is tghere a 120v problem as well, or is that working OK. Or at east partially.

 

[Lou39]

Thanks for your interest.
Here's what I found; altho I checked the voltage at the panel and across the batt posts I didn't check ground from the positive post to the chassis. Bingo!< 6volts. I'm guessing but when idle it shows 12v at the converter but under a load the ground fades.
Wizards reference to the chassis got my wheels turning, thanks so much.
I'm getting a 30A outlet installed so I can use the AC stuff in its parking space.
Thanks again.

 

[grashley]

PLEASE NOTE  While the electrician should know this, a 30A RV outlet is 120V, NOT 240V like a similar dryer outlet.  Make SURE they wire it correctly!

 

[Rene T]

PLEASE NOTE  While the electrician should know this, a 30A RV outlet is 120V, NOT 240V like a similar dryer outlet.  Make SURE they wire it correctly!

It would be much safer to just install a 50 Amp receptacle and use an adapter 30 to 50 Amp for now. Then if you change RV's later on down the road with 50 Amp, you'll be all set up.

http://www.rvparksupplies.com/mm5/merchant.mvc?

 

[Lou39]

Good advice, thanks.

 

[cerd]

It would be much safer to just install a 50 Amp receptacle and use an adapter 30 to 50 Amp for now. Then if you change RV's later on down the road with 50 Amp, you'll be all set up.

http://www.rvparksupplies.com/mm5/merchant.mvc?

Specifically, the wire needs to be rated for 50A for that purpose. You can safely have a 50A receptacle on 30A wire, as long as the circuit breaker doesn't exceed 30A.