Onan gold marquis 5500 popping 20a breaker
Tim fm CT
Our Onan gold marquis 5500 is popping the white 20a
breaker after running for 10-15 minutres with A/C on. The black 30a
breaker appeares to be fine.
The onan person said that it could be wired wrong IE
20a circuit going to 30a etc. The gen set has about 70 hours on it.
That's what it had when get bought the RV. That seems like an unusual
diagnosis.
Though I'd ask the group about it.
Tim fm CT
Hustlin' Hank
I would think that the Generator is fine. It sounds like the A/C unit
is wired incorrectly, or there is something else on the circuit.
Together they are drawing more than 20 amps. Do you have anything else
on that same circuit? To find out, shut the circuit breaker off and
see what works and what don't. If something doesn't work, then that
appliance running in conjunction with the A/C is overloading the
circuit. Try turning that appliance off and see if the circuit blows.
If it still blows the circuit, it either is drawing more than 20 amps,
you have a bad circuit breaker, wrong size wire, wrong breaker, or
something else.
Hope this helps.
Hank
Bob Hatch
I would first guess that it's a bad breaker. They're expensive, but not
prohibitive. Try that first.
--
"There are no jobs that Americans
will not do. There are jobs Americans
will not be hired for because an
illegal alien has taken it."
"Illegal Alien = Job Thief"
Steve Wolf
determine the amount of current draw to see if it is correct for that
air conditioner. If it is, then replace the breaker.
Steve
www.wolfswords.com under the motorhome link
nothermark
wrote:
I have seen breakers fail. I'd try to get hold of a clamp on ammeter
and check the current through the breaker assuming you can get to the
wiring to it.
Alan Robinson
"Tim fm CT" <r.d...@snet.net> wrote in message
news:bb29361b3c6gggha9...@4ax.com...
It's customary for the 30a breaker to feed one roof air and most normal
loads, while the 20a breaker feeds the other roof air (and, on a 50a system,
a few other loads). If the connections are reversed, it's usually not noted
until things are hot enough to need the a/c while somewhere park power isn't
available. Depending on how and when an rv is used, this may be years after
the misconnection took place.
Run the gen with only the 30a breaker switched on, and go thru the rv noting
what does and doesn't have power. Now repeat with only the 20a breaker
switched on. This should give you an idea whether the connections are
correct or reversed. If they are reversed, fixing this should take care of
your problem. If they are correct, it's time to find someone with a clamp-on
ammeter and measure the current draw on the 20a leg. If it's more than 20a,
you need to find and fix the problem. If it's less than 20a, then the
breaker needs to be replaced.
NOTE: this MAY be a problem with the a/c - the compressor in the a/c
compresses the freon in the system (which heats it up), runs it thru a
condensor (where the freon gives up heat to the outside air), then the
compressed and cooled freon goes thru an orifice into the evaporator - the
expansion as it goes from the hi-pressure side into the low-pressure side
cools it to 30 degrees or so, and the inside fan blows air thru the
evaporator to produce the cool air you feel. The problem with this is that
when the thermostat thinks the evaporator airflow is cool enough, it shuts
the compressor off, BUT IT TAKES 2-3 minutes for the hi pressure to bleed
thru the orifice and the system pressure to equalize. The compressor starts
easily when system pressure is equalized, but requires SIGNIFICANTLY more
power to start if high-side pressure is still high, i.e. if the thermostat
turns the compressor back on too soon. Actually, in a lot of cases the
comprssor may not be able to start at all - in this case, it'll be trying to
draw 40-50 amps, which will pop a 20a breaker pretty quickly. Again, this is
something that's easiest to find with a clamp-on ammeter, as you'll see 10a
or so draw as the a/c is running normally, then 3-4a draw when the
compressor switches off (but the fan is still running), then after a minute
or so a spike to 40+a just before the breaker trips. The main way a/c
manufacturers keep this from happening is a 'dead band' of 3-5 degrees
between the temp the thermostat turns the compressor off and the temp it
turns it back on. If the thermostat is reading the air temp out of the
evaporator, this works well. If the capillary tube from the thermostat is
touching metal, the temp may change faster than the time it takes for system
pressure to equalize, and the thermostat tries to restart the compressor
before system pressures have equalized. Search for a thread with Tom (Altar)
from a couple years back where this was the case.
Alan
Tim fm CT
On Wed, 7 Jul 2010 21:40:21 -0700, "Alan Robinson" <a...@bmi.net>
wrote:
Thanks, Hank,Bob,Steve,nothismarkeither,Alan.
I'll combine my reply/update. BTW:The coach has a 50 amp service
but only one A/C.
After calling Tiffin and Onan I decided to at least determine that the
GenSet is up to specs. I did get advice pointing to the coach and the
genset. You guys were pretty much on the mark. Cripe! Having Onan,
Check the 20a breakerwith a load (it passed their specs) and changing
the oil and filter was $249.00.
I put the refer on gas, and checked the hot water heater. It was on
electric. I shut it off. Don't think anything else was on.
I then ran the A/C again and it ran fine.
Like one of you mentioned maybe the one A/C that is installed is on
the 20amp breaker and not the 30amp.
Having only one A/C wouldn't it be better to have it on the 30amp
breaker? Just to avoid this situation?
Is it a "do it yourself" job, to do that?
thanks in advsance,
Alan Robinson
>
>
> Thanks, Hank,Bob,Steve,nothismarkeither,Alan.
> I'll combine my reply/update. BTW:The coach has a 50 amp service
> but only one A/C.
> After calling Tiffin and Onan I decided to at least determine that the
> GenSet is up to specs. I did get advice pointing to the coach and the
> genset. You guys were pretty much on the mark. Cripe! Having Onan,
> Check the 20a breakerwith a load (it passed their specs) and changing
> the oil and filter was $249.00.
>
> I put the refer on gas, and checked the hot water heater. It was on
> electric. I shut it off. Don't think anything else was on.
> I then ran the A/C again and it ran fine.
>
> Like one of you mentioned maybe the one A/C that is installed is on
> the 20amp breaker and not the 30amp.
> Having only one A/C wouldn't it be better to have it on the 30amp
> breaker? Just to avoid this situation?
>
> Is it a "do it yourself" job, to do that?
>
> thanks in advsance,
>
>
From your description, it sounds like you have the two circuits reversed,
i.e. the a/c and most major loads are on the 20a breaker rather than the 30a
breaker. And yes, it would be better to have the a/c on the 30a circuit. In
most cases it'll be a do-it-yourself job to correct this. Find the flex
conduit going from the genset to the coach - it SHOULD go to a connection
box with a removable lid, mounted in or very near the gen compartment. Take
the lid off, you should see 5 wires coming in from the genset: one black,
one black with yellow stripe, two white, and a green. Leaving the box and
going into the coach should be two romex cables, with each one having a
black, a white, and a bare copper wire. One genset black and one genset
white will be connected to the black and white of each romex cable with
wirenuts, the genset green will be connected to both bare coppers with a
wirenut.
Carefully tag the romex and genset blacks, then switch the two connections,
i.e. if genset black was connected to romex black A and genset black/yellow
to romex black B, move genset black/yellow to romex black A and genset black
to romex black B. You don't have to switch the white (neutral) connections,
as they connect at the same point in the genset and are electrically
identical. Make sure your new connections are secure, put the cover back on
the box, and enjoy.
Alan
Tim fm CT
wrote:
>
Thanks Alan,
I'll print your reply and take it outside as I
check those boxes.
Tim fm Ct
Tim fm CT
wrote:
>
Just to be sure:
I found a "Transfer Relay Delay Dual Input Genset" box.
It has three buses: each bus has four terminals labeled
gnd--line 1- -neut - -line 2.
left hand bus is labeled, "genset",
middle bus is labeled, "shore power",
right hand bus is, "coach panel".
In terms of trouble shooting I know the a/c runs just fine on shore
power, (30a cord) but I'm not sure if the electric hot water heater
was on or not. I haven't plugged into 50a yet. Seems like it's not
needed and why pay extra electric charges for 50a?
Since the genset has a 20a and a 30a breaker, can I expect that there
are two main breakers for the shore power that are also 20a and 30a?
Tim fm CT
Bob Hatch
Not likely. You will most likely find a pair of tied 50 amp, or what is
more commonly called a double pole breaker. On 50 amp shore power you
have 2 50 amp lines for a total of 12,000 watts. On 30 amp shore power
you have 3,600 watts of available power.
--
"There are no jobs that Americans
will not do. There are jobs Americans
will not be hired for because an
illegal alien has taken it."
"Illegal Alien = Job Thief"
http://www.bobhatch.com
http://www.tdsrvresort.com
http://www.keepazsafe.com/
Alan Robinson
In most cases, this is a little further along the path from the genset to
the coach than the box I was talking about, but you can do the swap here,
too. And, since they've labeled things for you, it will make doing it pretty
easy. All you have to do is, on the genset bus, move the wire on the line 1
terminal to the line 2 terminal, and the wire from the line 2 terminal to
the line 1 terminal. Make sure the connections are tight, close the box,
done.
Since the coach has a 50a setup, the main breakers in the coach power panel
are most likely a pair of 50a breakers with the handles ganged together -
for rv purposes, a 50a hookup is 50a/240v but is treated in the coach as two
50a/120v. The genset breakers are the equivalent of the breakers on the
pedestal you plug into (limiting current draw to what the source can
supply), not a replacement for the coach main breakers.
Alan
Tim fm CT
wrote:
good grief! That is one heck of a difference. I had no idea.
Tim
Tim fm CT
wrote:
Thanks Alan. The sure sounds less complicated.
thanks again,
Tim
timc...@gmail.com
Hank
> I have a coachman chaparral 5th wheel 32 foot it has a 5500 gold marquis Onan, the AC keeps tripping the 30 amp on the gen
There is a meter (when used correctly) that can test each running appliance to see how many amps each appliance draws. This should tell you what your problem could possibly be.
Hank