BAC Forum

General Boards => Technical Support => Topic started by: Trige Gleim on November 17, 2019, 04:21:02 PM

Title: Rear A/C only operates when generator is running
Post by: Trige Gleim on November 17, 2019, 04:21:02 PM

Our 2007 Beaver Contessa has 3 roof A/C's (heat pumps). Just recently the rear (bedroom) unit has stopped working. The front and middle units are working.  We're currently hooked up to a 50 amp pedestal.  I'm no electrician but I know enough to check the breaker box and the RR A/C breaker is not tripped.  I started the generator to check the RR A/C unit and it ran perfectly.  Once I turned off the generator, the RR A/C unit shut off.  Please provide any suggestions on what I should check next.  Thank you!

Title: Re: Rear A/C only operates when generator is running
Post by: Fred Brooks on November 17, 2019, 04:39:43 PM

     Trige, Sounds like only 1/2 of your transfer relay is working. On generator, both legs are transferring power into the coach. Further proof on shore power check to see what else may not be working. Fred

Title: Re: Rear A/C only operates when generator is running
Post by: Larry Dedrick on November 17, 2019, 06:07:19 PM

Trige
            Just some information to add. Keep in mind that the #3 A/C will not operate when the clothes washer is operating. This prevents overloading the number 2 leg which they are both on, at least on our coach (2008 Beaver marquis). That is why there is a priority given to the washer.
            This may be of some help in analyzing your electrical situation.

Title: Re: Rear A/C only operates when generator is running
Post by: Trige Gleim on November 17, 2019, 11:32:46 PM

Thank you Fred and Larry.  I will use your advice towards figuring out the problem.  Fred, I sent you a PM.

Title: Re: Rear A/C only operates when generator is running
Post by: Bryan Beamon on November 18, 2019, 01:04:06 AM

Trige, our 07 Contessa is wired with the center  and front  ac on different legs. If both are working while on 50 amp service you transfer switch would seem to be working. Another weird ac problem hit us this summer with our external surge protector female connector made inconsistent connection with our power cord . Once I removed the surge protector everything came back on line

Title: Re: Rear A/C only operates when generator is running
Post by: Trige Gleim on November 18, 2019, 05:58:05 PM

The culprit ended up being the Automatic Transfer Switch.  Thanks to all for the input and especially to Fred for the phone call walking me through the process.