A/C breaker trips

[John Churchill]

Well, I just got my generator started for the first time ever. Onan
7kW with a 20 amp and 30 amp breaker. When I turn on the forward A/C,
it runs for a while (a couple of minutes), then trips the 20 amp
breaker, even with everything else switched off. When the AC is off,
the breaker does not trip. I have only used shorepower on a 15 amp
circuit (with a long skinny cord to boot) and it trips that too,
although I am not sure that is a good test. The owner's manual says
that unit ought to draw 14 amps. I understand there is a much bigger
transient load as it cycles, but shouldn't it be able to handle that?
The rear A/C unit does not seem to run, so nothing to report there.
Any ideas of what to do or check? Thanks.

[Pete Masterson]

When the compressor cycles on, the AC can (very briefly) draw well over 20 amps. Most circuit breakers are able to ignore the transient draw -- so I'd suspect a bad breaker that's too sensitive.

As for shore power with 15 amp circuit, I would expect the breaker to trip almost immediately. The standard rooftop ACs draw 14+ amps normally and _any_ other load (lights, battery charger, water heater electric element) will put you way over the top. It's hard enough to keep the AC (and other typical loads) happy on a 30 amp circuit.

Go buy a 12 gauge extension cord. A "skinny" cord is probably dumping a lot of energy as heat instead of delivering it to your coach -- and it's a dangerous fire risk. Look at "contractors" extensions in a home center for a 12 gauge model. Get a cord that's as close to the actual length you need as extra cord will reduce the electrical efficiency.

Pete Masterson

'95 Blue Bird Wanderlodge WBDA 42

El Sobrante CA

"aeonix1@mac.com"

On Jun 29, 2008, at 12:15 PM, John Churchill wrote:

Well, I just got my generator started for the first time ever.  Onan

7kW with a 20 amp and 30 amp breaker.  When I turn on the forward A/C,

it runs for a while (a couple of minutes), then trips the 20 amp

breaker, even with everything else switched off.  When the AC is off,

the breaker does not trip.  I have only used shorepower on a 15 amp

circuit (with a long skinny cord to boot) and it trips that too,

although I am not sure that is a good test.  The owner's manual says

that unit ought to draw 14 amps.  I understand there is a much bigger

transient load as it cycles, but shouldn't it be able to handle that?

 The rear A/C unit does not seem to run, so nothing to report there. 

Any ideas of what to do or check?  Thanks.

[erniecarpet@...]

Sorry, if I missed what year coach this is, please post your name, coach and location as stated on the Home page. Thank you,

Ernie Ekberg
83PT40
Weatherford, Tx--Livingston, Mt
Wanderlodgeforum.org, owner

---

Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.

[Robin]

--- In WanderlodgeForum@yahoogroups.com, Pete Masterson
wrote:
>
> When the compressor cycles on, the AC can (very briefly) draw well
> over 20 amps. Most circuit breakers are able to ignore the transient
> draw -- so I'd suspect a bad breaker that's too sensitive.
>
> As for shore power with 15 amp circuit, I would expect the breaker to
> trip almost immediately. The standard rooftop ACs draw 14+ amps
> normally and _any_ other load (lights, battery charger, water heater
> electric element) will put you way over the top. It's hard enough to
> keep the AC (and other typical loads) happy on a 30 amp circuit.
>
> Go buy a 12 gauge extension cord. A "skinny" cord is probably dumping
> a lot of energy as heat instead of delivering it to your coach -- and
> it's a dangerous fire risk. Look at "contractors" extensions in a
> home center for a 12 gauge model. Get a cord that's as close to the
> actual length you need as extra cord will reduce the electrical
> efficiency.
>
> Pete Masterson
> '95 Blue Bird Wanderlodge WBDA 42
> El Sobrante CA
> aeonix1@...
>
>
>
> On Jun 29, 2008, at 12:15 PM, John Churchill wrote:
>
> > Well, I just got my generator started for the first time ever. Onan
> > 7kW with a 20 amp and 30 amp breaker. When I turn on the forward A/C,
> > it runs for a while (a couple of minutes), then trips the 20 amp
> > breaker, even with everything else switched off. When the AC is off,
> > the breaker does not trip. I have only used shorepower on a 15 amp
> > circuit (with a long skinny cord to boot) and it trips that too,
> > although I am not sure that is a good test. The owner's manual says
> > that unit ought to draw 14 amps. I understand there is a much bigger
> > transient load as it cycles, but shouldn't it be able to handle that?
> > The rear A/C unit does not seem to run, so nothing to report there.
> > Any ideas of what to do or check? Thanks.
> >
>
Pete-
Thanks for the assist.

My primary shorepower problem is lack of a good household circuit. I
need to get an electrician to create a new 220 V, 50 amp RV shorepower
outlet.

The genset (and breaker) are a few years old,
but just today run for the first time. The breaker does not trip when
the unit is first turned on, only after it has run a bit. It may be a
bad breaker, but I am thinking probably something else. Any other ideas?

[Pete Masterson]

If the breaker trips just after (or as) the compressor cycles on, then it's likely that the breaker has gotten weak (or is the wrong type). I can watch the amp gauges as the AC compressors cycle and I can see the needle jump into the red zone for a fraction of a second -- if the breakers on the circuit didn't have the built-in trip delay, they'd pop every time. 

It is also possible that there's something wrong with the AC compressor motor, but that's usually accompanied by odors, (oily smell, ozone, or burning insulation) that tip you off. 

Initially, when the compressor first starts after the AC has been off for awhile, there's little resistance to the start. Once the compressor has run, there's some built up pressure that bleeds off over time... still there's more resistance to the compressor motor when it cycles on once the system has been pressurized (running) for a time.

Pete Masterson

'95 Blue Bird Wanderlodge WBDA 42

El Sobrante CA

"aeonix1@mac.com"

<snip>Pete-

Thanks for the assist.

My primary shorepower problem is lack of a good household circuit.  I

need to get an electrician to create a new 220 V, 50 amp RV shorepower

outlet. 

The genset (and breaker) are a few years old,

but just today run for the first time.  The breaker does not trip when

the unit is first turned on, only after it has run a bit.  It may be a

bad breaker, but I am thinking probably something else.  Any other ideas?

[Don Bradner]

A/C compressors normally have a startup delay, typically around 5 minutes. The
A/C fan will be on, but not the compressor, which is the heavy power draw. Do
you have generator gauges that tell you what the A/C amps are on each leg?

On 6/30/2008 at 1:17 AM Robin wrote:

>The breaker does not trip when
>the unit is first turned on, only after it has run a bit. It may be a
>bad breaker, but I am thinking probably something else. Any other ideas?

[Robin]

--- In WanderlodgeForum@yahoogroups.com, erniecarpet@... wrote:
>
> Sorry, if I missed what year coach this is, please post your name,
coach and
> location as stated on the Home page. Thank you,
>
> Ernie Ekberg
> 83PT40
> Weatherford, Tx--Livingston, Mt
> Wanderlodgeforum.org, owner
>
>
>Sorry.

John Churchill
1980 FC33
Sanibel, FL

[Chuck Wheeler]

John,

Maybe I missed something, but which BB do you have? If it has the older Duo-therm units they pull more current, but at least one should be able to run on a 7kw generator. I have run our whole coach on a 7.5kw generator when I was working on the Perkins/Kohlar generator. I would start with the start and run capacitors. If you have a clamp on ammeter check the running load. If it is more than what is stated on the name plate there is a problem. Also check the output of the generator under load. If the voltage drops excessively the current will go up. Our front unit kept tripping breakers and I finally replaced it.

When we got our FC31 one of the AC switches by the driver was bad and would not let the front unit run.

Where are you located?

- Chuck Wheeler-

FC 31SB Fort Worth TX

---

From: WanderlodgeForum@yahoogroups.com [mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of John Churchill
Sent: Sunday, June 29, 2008 2:16 PM
To: WanderlodgeForum@yahoogroups.com
Subject: [WanderlodgeForum] A/C breaker trips

Well, I just got my generator started for the first time ever. Onan
7kW with a 20 amp and 30 amp breaker. When I turn on the forward A/C,
it runs for a while (a couple of minutes), then trips the 20 amp
breaker, even with everything else switched off. When the AC is off,
the breaker does not trip. I have only used shorepower on a 15 amp
circuit (with a long skinny cord to boot) and it trips that too,
although I am not sure that is a good test. The owner's manual says
that unit ought to draw 14 amps. I understand there is a much bigger
transient load as it cycles, but shouldn't it be able to handle that?
The rear A/C unit does not seem to run, so nothing to report there.
Any ideas of what to do or check? Thanks.

[Gregory OConnor]

After a long winter the start capacitors need to be up to snuff. At
issue, I just replace them to insure I am giving a motor a good kick
start. they store energy so dont go at it blind folded.

http://www.wikihow.com/Check-a-Start-Capacitor

GregoryO'Connor
94ptRomolandCa




--- In WanderlodgeForum@yahoogroups.com, "Chuck Wheeler"
wrote:
>
> John,
>
> Maybe I missed something, but which BB do you have? If it has
the older
> Duo-therm units they pull more current, but at least one should be
able to
> run on a 7kw generator. I have run our whole coach on a 7.5kw
generator
> when I was working on the Perkins/Kohlar generator. I would
start with the
> start and run capacitors. If you have a clamp on ammeter check
the running
> load. If it is more than what is stated on the name plate there
is a
> problem. Also check the output of the generator under load. If
the voltage
> drops excessively the current will go up. Our front unit kept
tripping
> breakers and I finally replaced it.
>
> When we got our FC31 one of the AC switches by the driver was bad
and would
> not let the front unit run.
>
> Where are you located?
>
> - Chuck Wheeler-
> FC 31SB Fort Worth TX
>
>
> _____
>
> From: WanderlodgeForum@yahoogroups.com
> [mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of John
Churchill
> Sent: Sunday, June 29, 2008 2:16 PM
> To: WanderlodgeForum@yahoogroups.com
> Subject: [WanderlodgeForum] A/C breaker trips
>
>
>
> Well, I just got my generator started for the first time ever. Onan
> 7kW with a 20 amp and 30 amp breaker. When I turn on the forward
A/C,
> it runs for a while (a couple of minutes), then trips the 20 amp
> breaker, even with everything else switched off. When the AC is
off,
> the breaker does not trip. I have only used shorepower on a 15 amp
> circuit (with a long skinny cord to boot) and it trips that too,
> although I am not sure that is a good test. The owner's manual says
> that unit ought to draw 14 amps. I understand there is a much
bigger
> transient load as it cycles, but shouldn't it be able to handle
that?
> The rear A/C unit does not seem to run, so nothing to report
there.
> Any ideas of what to do or check? Thanks.
>

[Wilhelmus Schreurs]

Robin:
If you have a 30 amp breaker, try it on there. let it run somewhat longer, but not continous.
If you can get an ammeter, you should try to see what that A/C draws.

Bill 84 FC 35 SB "$quanderlodge"
Terrace, B.C. Canada

__