Skip to main content ↑ ↓
Topic: 110 AC power problem (Read 972 times) previous topic - next topic

110 AC power problem

Have not really got into this yet.  I noticed last night that the AC voltage was low and that the red reverse polarity light was on in the polarity voltage indicator meter.  I do not appear to have any AC voltage in the coach.  My converter is working okay.  I am on a 20 amp circuit at home which I use for charging and maintaining the batteries.  This was fine yesterday morning with nothing out of order and the green polarity light on and then last night the red polarity light was on and the voltage is down around 100vac.  Had done nothing in the coach to cause this???  I have checked my shore power cord and my T-bone cord and both are good, plus my voltage on that circuit going to coach is okay at 123vac.  I did unplug the coach.  This is on the older U225, so I do not have all that fancy stuff to check.  None of my fuses are blown.

Edit:  Have a "Powerwatch" meter.  I thought the voltage was low because it read 100, but it reads 100 when the coach is not hooked up to shore power.  But the "Powerwatch" Red reverse polarity light is on when the coach is hooked up and it shows no voltage.  I have another ac meter plugged in a outlet and it shows no voltage either.

How does one go from positive polarity to reverse polarity without messing with anything? 
1994 U225
build #4514

Re: 110 AC power problem

Reply #1 –
Start by checking all the shore power cord and adapters carefully.  You could have a burned end that is making contact between elements that "don't play well together".

If no problem, check connection in the main breaker box, ATS, etc.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: 110 AC power problem

Reply #2 –
Appears to be a bad dogbone.
1994 U225
build #4514

Re: 110 AC power problem

Reply #3 –
Great-- sounds like a cheap easy fix!

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: 110 AC power problem

Reply #4 –
Never a bad idea to occasionally check cord temps by hand at all the adapter connections after the rig has been drawing amps for a while (air conditioner).
Pierce & Gaylie
'93 U300/36
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: 110 AC power problem

Reply #5 –
It was a bad dogbone!  But the darn thing tested good with VOM.  The 30 lugs were not aligning properly and not connecting good.  The new one just arrived today.  No RV stores locally when you can just go in and find one on the shelf.  Now everything is up and running and the most importantly, the batteries charging and maintaining!  Thanks everyone!

Oh, found out that I have a newer transfer switch???  Have a Iota ITS-50R Transfer Switch.  They were not manufactured until sometime in the 2000s.  Never saw anything about that when looking in the coach's history.
1994 U225
build #4514

Re: 110 AC power problem

Reply #6 –
Pardon my ignorance, but what and where is this doggone dogbone thing a ma jig. Just in case. jc
JC
1999 U320

Re: 110 AC power problem

Reply #7 –
Quote from: hotonthetrail –
Pardon my ignorance, but what and where is this doggone dogbone thing a ma jig. Just in case. jc

A dog bone is another name for an adapter.  so 15 male to 30 female or 30 male to 50 female.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: 110 AC power problem

Reply #8 –
In my experience "Dog-bone" adapters are the cause of many electrical problems/failures. The last (of several) that failed very nearly cost me a new transfer switch. Advisable to treat them gently.
Chad & Judy
'98 U320 - Build #5315
Motorcade 16317
Wickenburg, AZ

Re: 110 AC power problem

Reply #9 –
This is rather obvious, but...One of the maintenance items I perform each year is to take some steel wool and clean all the prongs and spray some electrical contact cleaner in the female ends of the dogbones I use.  This will improve the quality of the contact area and make a better connection.  Indeed, never pull out the connection (or any electrical connection) other than by the plug itself.
Peter & Beth Martin
No Forrest? What have you done?
MC# 15890 until Dec 2016; FMCA #F329677
Cincinnati, OH

Re: 110 AC power problem

Reply #10 –
I think not all dog bones are created equal. I bought an adapter at Camping World. The purpose was to allow plugging to a 30A outlet. It works, but energizes only one power leg in the coach. It energizes the wrong power leg to be useful. This may be a "user error."

The coach came with a "home brew" adapter that would allow two 30A outlets to power a 50A outlet into which I could plug the coach. With one 30A outlet, I could choose which leg to energize. I built an adapter that uses one 30A outlet to activate both power legs in the coach. Current is still limited to 30A total, but all 120VAC circuits are alive. This works on our coach because it has no 240VAC appliances and everything works fine if the two power legs are in phase.

I look forward to correction if you find flaws in my presentation.

J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: 110 AC power problem

Reply #11 –
J.D.

ALL 30 amp male to 50 amp female adapters should have the single hot leg on the 30 amp side wired to BOTH hot legs on the 50 amp side.  Period.  Return any not wired that way and get your money back.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020