Automatic Transfer Switch/ No power to RV

[hsbill]

    I have an RV with a PowerMax PTMS-50 Automatic Transfer switch.  The RV electrical system works fine when connected to shore power.  However, when running the generator the RV has no power.  I checked the power running to the transfer switch from the generator with a volt meter and it was 120, but I couldn't get a reading for power coming out of the switch to the motorhome.  The transfer switch would just make a "buzzing noise".
    I replaced the transfer switch with the same make/model and I have the same problem.  Generator runs, appears to supply power to the transfer switch,  the transfer switch buzzes, but no power in the motorhome. 
Thoughts????

 

[Robert K]

The new one is probably bad. This just happened to me ,installed new switch no power from gen.Sent it back got replacement all works now.I would bet circuit board bad

 

[fairway2002]

Did you change just the relay or the board also? I know my last two switches the board puts power to relay. Not a 120volt relay.

 

[hsbill]

Thanks for the replies. I wonder what the odds are of having a bad circuit board on two of them?  I replaced the whole box, which has the circuit board in it. 

 

[fairway2002]

Turn braker off on Gen. Relay still humm? Your Gen have any outlets to see if there is amperage not just volts? FYI  I would do all this with main power off on your panel. No need to screw other 110 volt things up. 

 

[hsbill]

Thanks for all the help.  After exhausting all the possible solutions I had, I called PowerMax.  They asked for the serial number from the switch and then informed me they had a bad set of circuit boards come through a while back.  They mailed me a new circuit board for the automatic transfer switch and.............it worked!  Thanks again for the replies.