Dometic fan motor replacement issue

[Joel Sheriff]

I had a Blower motor & capacitor changed out a short while ago. I ordered the motor from a tech friend in AZ off the info inside the dometic low profile 13,500 unit.  Since the motor change, my GFI outlet pops every time I turn on heat or ac.  Could it be the motor was the wrong one or is my GFI not handling the load? Any help would be appreciated. 

[Gary 05 AMB DST]

Does your A/C power go through a GFI?

Gary 05 AMB DST

[Chuck B 2004 Windsor]

If your tech friend is a good friend, he should be able to answer that.   Chuck B 2004 Windsor

[TomV48]

56 minutes ago, Gary 05 AMB DST said:

Does your A/C power go through a GFI?

Gary 05 AMB DST

As a 05 Ambassador guy too, I ask the same question.    All I can think is maybe some seemingly benign a/c hook up is reversed.   I'm thinking the only way your GFCI is in the AC loop might be the thermostat ?   But I thought that was DC.  You might, just for the heck of it go back and look at the point at which the motor is connected to the alternating current in the air conditioner and see if it could possibly have been reversed. With a DC would make things run backwards with an AC it shouldn't run backwards but it might just be creating a ground fault somewhere. 

Edited March 7, 2023 by TomV48

[jacwjames]

What was the part number of the motor you ordered and received?

Here is the parts breakdown for the AC unit based on the number on the tag you posted.

https://www.edometic.com/ALLUSR/sp.nsf/o/9a8ccc6bcaeef05a85257ca800057554?OpenDocument&Start=1&Count=9999&Expand=8&RestrictToCategory=CPPT78A-NNMU

Here is the motor, did it look like this?  https://www.amazon.com/Dometic-3314471-011-Fan-Motor-Service/dp/B07XPDY5TJ

Who did the swap out?  I had to replace a motor on my unit in 2015, not to bad of a job, AC was still working fine but I decided to replace both AC units in 2021 when the rear one started to make noise, I was going to replace that motor but could not find one available.  So I replaced both with 15K BTU high capacity units and upgraded the thermostat to a Easy Touch MicroAir.  At the time the new units were ~$1150 each but they've doubled in price since then. 

[Tom Cherry]

4 hours ago, Gary 05 AMB DST said:

Does your A/C power go through a GFI?

Gary 05 AMB DST

The AC Power to the individual units go through a standard breaker.  There is one breaker for each.  If that CB is a GFCI then some well meaning individual has replaced it.  The only GFCI Circuits in the MH should be the kitchen and bath/vanity receptacles that are within 5 ft of a source if water.  Often times Monaco goofed and ran the refrigerator inverter (the icemaker circuit .not the heating element) through the GFCI and that caused issues and false trips.

[Joel Sheriff]

I was dumb that day and trusted my bud in Az to give his part guy the info I sent him and the motor would be the right one, the same as the label I posted. I had a tech in Socal where I was put it in. The ac and heat worked, fan blows but then it engaged the compressor out heat pump it kick off the GFI.  Yes it was similar with a new capacitor.  Again I used the tag inside of unit, attached, to order the right motor. Could it be a bad or weak gfi? 

The GFI works fine with fine with evening else on it. Doesn't fault with anything but the dometic 

[Tom Cherry]

10 minutes ago, Joel Sheriff said:

I was dumb that day and trusted my bud in Az to give his part guy the info I sent him and the motor would be the right one, the same as the label I posted. I had a tech in Socal where I was put it in. The ac and heat worked, fan blows but then it engaged the compressor out heat pump it kick off the GFI.  Yes it was similar with a new capacitor.  Again I used the tag inside of unit, attached, to order the right motor. Could it be a bad or weak gfi? 

The GFI works fine with fine with evening else on it. Doesn't fault with anything but the dometic 

Joel, i remember many electrical issues going back 10 plus years including the Progressive surge protector being incorrectly installed.  i also remember I think. GFCI issues several months or so back.  i believe you had a Eaton Wiring or Hubbell or Levitan installed.  it should be a 20 amp GFCI.... There are 96 electrical drawings, not bundled in this file. 

read my previous post.  the GFCIis for the outlets.  the 30 A Inverter CB provids power to the Inverter.  that is slit inti TWO 20A circuits that come OUT of the Inverter.  one goes to J Box 7.....and goes on the Microwave. The other goes to the same J box  and then one to the J Box 3. then splits and the refrigerator icemaker circuit and then the GFCI is installed.  now you reported some issues with a installed bed lift.  God only know what a repair person might have done or modified if a 120 VAC device was added.

i have spent a lot of time in them.  please take the time to download the entire 96.  these are excellent and easy to read from a repair or a technician standpoint.

i also included the main AC layout.  i recommend you get a qualified electrician to trouble shoot.  all you are doing is damaging the GFCI by continuing to run the AC unit. there is no way that can trouble shoot the issue remotely.  too many variables. 

you dont state which AC is causing the issue. The Inverter CB is  on the same side as the Rear AC.  Then, it gets worse.  Each AC goes through the EMS for load shedding.  any miss wired device where the back and whit and ground were wired or paired up incorectly could cause the GFCI TO GET A FALSE SIGNAL.  

We dont know if the new motor is wired correctly or if it is a different HP or amp rating than the original.  since you did not have the issue before, without doing a complete wiring inspection and taking voltage and amp readings, i cany help, nor advise.  add in the EMS. if the EMS is sensing an overload and that CB is tripping or shedding and there is some transient surege or fault in it and trhat is sending a false signal ti the GFCI....there is no way I can tell you to measure here or there or change this.

if you want to work with someone and you have the skillset and meters and understanding, that would be great.  

However, this exercise must be taken offline as it will be, maybe, quite complex.  when there are too many cooks trying to get the stew to have a certain flasvor....it never works.  if some one or two decide to assist, please post that and then we will wait until it is resolved and then get summary.  otherwise it will be futile, based on what yoiu posted to trouble shoot online.

my suggestion.  quit using that unit.  you don't know whether the EMS IS the source and you don't want to keep tripping it.  the age of that systrm will be expensive to fix.  same goes for the GCFI.

i don't knpwif it a fire hazard, so shutting down and troubleshooting and fixing is the best solution

thanks for understanding 

 

38040005 (DIAGRAM, 120V AC).pdf

[Joel Sheriff]

Tom, understood. I stopped using the unit except for the furnace. I only turned it on to show the tech. He's the one who suggested changing out the GFI.  I will take this off line to further explore. I have the wiring diagram from before. I use the bed actuator and no issue with GFI.  It is the rear dometic 13.5 unit, front works fine 15k. I have to possibly take exception to it being  wired correctly since when the tech put in the new motor it initially didn't run and he had to go back up to find a loose ground from replacement. A little scary. Tom, as usual, you are a plethora of info on this stuff and your opinion is law in my book. Thanks again, I may be looking for a new tech to troubleshoot this problem. 

[Tom Cherry]

2 hours ago, Joel Sheriff said:

Tom, understood. I stopped using the unit except for the furnace. I only turned it on to show the tech. He's the one who suggested changing out the GFI.  I will take this off line to further explore. I have the wiring diagram from before. I use the bed actuator and no issue with GFI.  It is the rear dometic 13.5 unit, front works fine 15k. I have to possibly take exception to it being  wired correctly since when the tech put in the new motor it initially didn't run and he had to go back up to find a loose ground from replacement. A little scary. Tom, as usual, you are a plethora of info on this stuff and your opinion is law in my book. Thanks again, I may be looking for a new tech to troubleshoot this problem. 

Good deal.  Keep after it.  We want this fixed but even doing it off line on the phone would be risky.  Just to take a little mystery out of it…and some folks offline Curiosity….  When you say the GFCI, you DO mean the GFCI receptacle.  If you have have any GFCI CB in the main panel, then they are NOT original.  On page 162, it plainly states STANDARD.  No building code or NEC or NFPA regulations specify GFCI.  THEY MUST BE STANDARD NON GFCI.

SO….tell us which one….so we all know….and then get it fixed.  If you don’t have a GFCI circuit breaker and it is the GFCI RECEPTACLE….it might be prudent to point out to the electrician that there is a distinct possibility that there is either a short in the new motor or it is the wrong motor and pulling the wrong current or miss wired then a transient false signal and it works it’s way up the line back to GFCI..  They are on the same line or side.

Good luck….

[Joel Sheriff]

Yes, the GFI, GFCI, I'm talking about is the receptacle there is no other GFI in the coach. This one come right off the inverter side and covered the bathroom and galley.  I'm am concerned with the original install of the motor not that it's the wrong motor. Thank you again for this current problem assistance. 

[Gary 05 AMB DST]

8 hours ago, Joel Sheriff said:

Yes, the GFI, GFCI, I'm talking about is the receptacle there is no other GFI in the coach. This one come right off the inverter side and covered the bathroom and galley.  I'm am concerned with the original install of the motor not that it's the wrong motor. Thank you again for this current problem assistance. 

Joel, I think there is a GFI outlet in the outdoor radio box and the engine preheat  plug.

Gary 05 AMB DST

[Tom Cherry]

ALL.  OK, now we know.  The breakers are NOT GFCI.  The rear AC breaker is one the same “line” as the inverter breaker.  Therefore the current spike when the compressor motor (HP or AC) is PROBABLY causing a spike or a voltage drop that is significant enough to backfeed to the main panel and then travel through the inverter breaker and the inverter and finally “trip” the GFCI in the house outlet circuit.  You have to read exactly how the GFCI works….in that it is measuring the current or voltage on the neutral and comparing it to the line side.  A leaky icemaker coil will trip a GFCI as it thinks there is a dead short to ground which would result in a dangerous situation if you were holding a device….and used immersed your hand in water.  That’s why there is not a GCFI, BY CODE, on a refrigerator or microwave.

GARY,

Look at the print.  There is not a second GCFI….NOR is it mentioned or discussed in the owner’s manual.

it is time to let Joel get it resolved by a tech as that is the safest and best way.  Let’s refrain from further discussion until Joel gets help….otherwise the topic will have to be locked.

Thanks.