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Topic: Electrical System has me confused (Read 811 times) previous topic - next topic

Electrical System has me confused

Today I had to move the coach about 100ft to load it for a trip to Myrtle Beach this weekend.  The coach was plugged in to shore power and the a/c's were running.  I started the engine and turned off the a/c's before going out to unplug the shore power.  Every thing seemed totally normal.  Moved the coach to the driveway and started to use the leveling system.  NOTHING.  No 12v in the coach at all.  Left the engine running and got out to connect to shore power.  Monitor panel in the coach indicated 120v on both legs.  Circuit Breaker panel at foot of bed had 120v tested with multimeter on all circuits.  But nothing in the coach worked 120v or 12v all dead.  Shut the engine off.  Waited a few minutes and restarted the engine.  Turned on the Boost switch and everything in the coach worked total normally.  Started the generator and shut down the engine.  Everything normal.  Turned off the generator and went back on shore power.  Everything normal.  Is this possibly a transfer switch GOING bad.

Would hate to be without power this weekend.  Got time to replace a switch if I get one tomorrow.

Thanks for the help

Nick Caglw

Re: Electrical System has me confused

Reply #1 –
A lot of info there. You might be trying to mess with too many systems at once.  The transfer switch is for AC only. Shouldn't effect 12V. My normal routine is not only to shut off everything. I also trip the individual (not the main) AC breakers (three on my coach) So zero spikes can happen. So even on gen, or shore power. All the AC lines are dead.

It was unclear if after moving your coach and trying to level if the engine was running or not. On ours the engine running or the key in the run position will cause the HWH to default to travel mode.

Re: Electrical System has me confused

Reply #2 –
Quote from: Nick Cagle –

Would hate to be without power this weekend.  Got time to replace a switch if I get one tomorrow.

Thanks for the help

Nick Caglw

If you have the skill set to replace the automatic transfer switch, something that only controls the flow of 120VAC, then you have the skill set to prepare for and use if necessary a set of jumper wires.

IF you had no 12VDC, and the "Salesman's switch is on, you need to check your house battery.  Best to let it rest for 3 hours before measuring the voltage.  That will give you an accurate indication of state of charge.  Turning on a known current load for an hour or two, the re-checking the battery voltage will give you an idea of remaining capacity.

Re: Electrical System has me confused

Reply #3 –
check the ATS and see if it has power to it.. might be the reel. Pull the reel a half turn and check again

See if you have power on each side of the relays.. Power in should be on the face and other side of the one and on the face of the other... it will engage and will do the opposite(power on the face and power the the other side of the opposite relay).

Basement ATS first then the power is sent to the one under the bed. Same scenario..  If all have power then recheck the breakers but my guess is you will find the problem is at the basement ATS.

12v is the salesman switch probably.. if not its the batteries and maybe a fuse...

after that check all main fuses under the basement driver side and see if main breaker needs reset (not sure but it has a button on mine).

Re: Electrical System has me confused

Reply #4 –
If you have no power from the generator or shore power cable, check the voltage sensing relay in the transfer switch box.  On my rig, it's an orange Intermatic relay with a HI and LOW voltage setting.  It will only allow power to the transfer switches if the voltage is between the set points (about 112V and 130V).  I've found this thing is flakey.  If my ATS hasn't turned on when plugged in, just touching the LOW voltage adjuster and it will come on.  They are about $160 online, I just haven't got to the point of replacing it yet since I know how to work around it.

This would not affect your 12V systems though.  Not sure what to say there.

Re: Electrical System has me confused

Reply #5 –
You mentioned hitting the boost switch and then everything went back to normal...what happened when you removed the boost, or did you leave it closed?
 

Re: Electrical System has me confused

Reply #6 –
Quote from: SuperFore –
You mentioned hitting the boost switch and then everything went back to normal...what happened when you removed the boost, or did you leave it closed?
It stayed at everything OK when I turned it off.  The only thing I can think of is the transfer switch is mounted close enough to the 8.3 That the vibration from the engine shook the switch enough to make it. work.  This is of course all speculation on my part because as we speak everything is working as it should.
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