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  • Dwayne
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generator/electrical update
I think I've narrowed down why my generator (actually ATS) is puking out when trying to run both A/C units.  My Ch. Engineer gave me a meter to guage the amperage of a circuit while in use.  When I crank up either A/C, after a second or two and...

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Re: generator/electrical update
Reply #1
Dewayne,

Has either unit ever tripped a breaker when trying to start if not and from looking at the amp readings you took I think the units are OK if they were pulling excess amperage they would trip the breakers feeding the a/c units. You said...

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  • Dwayne
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Re: generator/electrical update
Reply #2
Onan twice now has blessed the generator and our company's Chief Engineer did too.  The units are each on a 20 amp breaker, neither has ever tripped one.  Once they manage to get past the startup without tripping the trasfer switch they continue...

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Re: generator/electrical update
Reply #3
Have you tried starting just the fan on both units after they are up and running then switch one of the units to cool let it settle down then turn on the second one   this way the fan motors are up and running should help some on the starting...

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Re: generator/electrical update
Reply #4
Bobby,

That is an excellent idea!

Since all else has failed, let's try putting some logic to this issue.  First, the breakers to the A/C units do not trip.  Second the shorepower connection does not seem to have an issue with the units either. ...

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Re: generator/electrical update
Reply #5
Knowing this is an old subject, Thought would try to simplify this .
First without a peak reading amp meter and a min/max reading AC Volt meter it is a guess at best, I would expect the actual peak amp load on starting the comressor would run...

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Re: generator/electrical update
Reply #6
Dave,

I agree with you hard to trouble shoot something over the internet to many variables but I did check my units just to compare his amp readings mine are close to what he was getting. Duo Therm made 2 models that are rated 13500 BTU at least...

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  • Dave Head
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Re: generator/electrical update
Reply #7
I find it interesting that he seems to say that the Coleman compressors
kick in immediately.
On the Dometic it delays about 3 minutes after the fan starts. Never
fails to throw me...
Quote
wg4t wrote:
Knowing this is an old subject,
Thought would try...


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  • Dwayne
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Re: generator/electrical update
Reply #8
There may be a very brief delay...ore or two seconds maybe.  I tried changing out the start capacitor but I shouldn't have as the one I bought said that it (and the start relay) was for a unit without those components.  The start capacitor burned...

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Re: generator/electrical update
Reply #9
Dwayne,
I found this you may want to read it someone had the same problem you are having with the transfer switch taking the generator out.

http://www.smokstak.com/forum/showthread.php?t=62921

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  • Dwayne
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Re: generator/electrical update
Reply #10
I'm so confused.  I changed the transfer switch because when turning down the thermostat causing one compressor to go off...the transfer switch would open.  Onan told me generator fine, bad transfer switch.  Seemed logical.  New transfer switch...

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Re: generator/electrical update
Reply #11
If you even suspect a wiring issue between generator and ATS, it is not that difficult to run a new wire between the two.

In the compartment (driver's side) immediately behind the generator is the junction box from generator to house wiring.  Drop...

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  • Dwayne
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Re: generator/electrical update
Reply #12
Thanks.  I may resort to that.  I'd still suspect that a wiring issue would show up in other ways.  Once both units are successfully started and running and even if you add in fridge, blow dryer, microwave...the generator is purring and the volt...

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Re: generator/electrical update
Reply #13
Dwayne,

Ya, your symptoms in your post immediately above do not point to a wiring issue. 

The momentary voltage drop upon addition of a heavy load is perfectly normal. 

I am not aware that any ATS was voltage sensitive enough that it will kick out...

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  • Dwayne
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Re: generator/electrical update
Reply #14
Think I'm going to see if one of our electrical service contractors will rebuild my old switch and see what happens.  Also going ahead with trying to get the right hard start capacitors for the A/C units.  I read through all the posts from the...

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  • Dwayne
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Re: generator/electrical update
Reply #15
The "right" hard start capacitor actually increased the amps on compressor start.  Dead end.  I have a call into the tech guy at ESCO to ask about the parameters of the 50 amp switch I bought from them.  Our chief engineer is telling me that I...

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  • Dwayne
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Re: generator/electrical update
Reply #16
ESCO says that I could replace my switch with a relay style one that would be more tolerant of low voltage but the simple contactor switch I bought is their most tolerant of contactor based switches and would need 97 volts for a millisecond to...

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Re: generator/electrical update
Reply #17
Generators rarely / never trip breakers as normaly the voltage will drop long before the amps go high enough and long enough to trip a thermo-magnetic breaker.

When using a 6.5 Onan, that is a very cheap example trying to act like a high class...

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  • Dwayne
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Re: generator/electrical update
Reply #18
I am just disgusted.  I changed out the A/C and only slight improvement.  It may run at under 11 amps but it starts at 15-16 so I am still having the issue though less frequently.  And I know for a fact that these new units don't work as good as...

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