Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 

Go Back   Thor Forums > Thor Tech Forums > Maintenance and Repair
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 02-01-2022, 08:30 PM   #1
Junior Member
 
Brand: Thor Motor Coach
State: Florida
Posts: 10
THOR #21140
AC runs on shore power but not on generator

Hi All,

Thanks in advance for any feed back!!

I have a 2021 Thor Magnitude. The AC runs fine on shore power but won't run on generator power. Then generator runs fine and powers all the other stuff it's supposed to but not the AC.

This happened once before and I pushed a bunch of buttons on the inverter, the battery disconnect and anywhere else I could find a button to try and reset something and it fixed it.


I can't remember nor did i do it systematically to figure out how I fixed it.

Anywho, I can't figure out how to get it working again.

Thanks again for any suggestions.

__________________
Maggie2021 is offline   Reply With Quote
Old 02-01-2022, 09:31 PM   #2
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
Your motorhome should have two air conditioners. Can you clarify problem: Do neither of them run from generator, or does one air conditioner run from generator and other not?
__________________
Chance is offline   Reply With Quote
Old 02-01-2022, 09:45 PM   #3
Site Team
 
16ACE27's Avatar
 
Brand: Thor Motor Coach
Model: ACE 27.1
State: Florida
Posts: 14,129
THOR #7035
Quote:
Originally Posted by Maggie2021 View Post
Hi All,

Thanks in advance for any feed back!!

I have a 2021 Thor Magnitude. The AC runs fine on shore power but won't run on generator power. Then generator runs fine and powers all the other stuff it's supposed to but not the A/C.

This happened once before and I pushed a bunch of buttons on the inverter, the battery disconnect and anywhere else I could find a button to try and reset something and it fixed it.


I can't remember nor did i do it systematically to figure out how I fixed it.

Anywho, I can't figure out how to get it working again.

Thanks again for any suggestions.
As chance asked: both A/Cs? have you really verified everything else in the coach is powered? Furnace? Microwave? Etc?

There's more to this story....................
__________________
Ted & Melinda
2016 ACE 27.1
2016 Chevy Sonic Toad - Selling
2020 Chevy Colorado Z71 Trail Runner Toad
2024 Chevrolet Trax 2RS - Soon 2B TOAD
16ACE27 is offline   Reply With Quote
Old 02-01-2022, 09:45 PM   #4
Senior Member
 
Brand: Thor Motor Coach
Model: Challenger
State: Maryland
Posts: 108
THOR #25281
Quote:
Originally Posted by Maggie2021 View Post
Hi All,

Thanks in advance for any feed back!!

I have a 2021 Thor Magnitude. The AC runs fine on shore power but won't run on generator power. Then generator runs fine and powers all the other stuff it's supposed to but not the AC.

This happened once before and I pushed a bunch of buttons on the inverter, the battery disconnect and anywhere else I could find a button to try and reset something and it fixed it.


I can't remember nor did i do it systematically to figure out how I fixed it.

Anywho, I can't figure out how to get it working again.

Thanks again for any suggestions.
Hello,
Your generator should have electrical breakers somewhere in the generator compartment. I bet that the one that controls the A/C is tripped. Worth a look at least
__________________
craigd853 is offline   Reply With Quote
Old 02-02-2022, 01:45 AM   #5
Senior Member
 
Brand: Thor Motor Coach
State: South Carolina
Posts: 694
THOR #22342
That is interesting. The Generator takes precedence over the Shore Pwr. So, if you run your SP and start the Generator, in about 15-30 sec, you will here the Transfer switch click over to the GEN. See if that works. If nothing, yes check the CB at the GEN panel outside.

I dont operate this way. this is trouble shooting,

You should trip breaker inside prior to selecting AC source, then when stabilized on GEN or Shore Pwr close the interior master breaker, then turn on your heavy start up load AC units. it also takes a min or so for the AC unit pressure to stabilize if you switch pwr source or just turn on and off AC unit.
__________________
txc2936@yahoo.com is offline   Reply With Quote
Old 02-02-2022, 01:13 PM   #6
Junior Member
 
Brand: Thor Motor Coach
State: Florida
Posts: 10
THOR #21140
Quote:
Originally Posted by Chance View Post
Your motorhome should have two air conditioners. Can you clarify problem: Do neither of them run from generator, or does one air conditioner run from generator and other not?
Thanks. Neither AC works on generator power. They work fine on shore power. The fans on the AC come on on generator power but not the compressors so it doesn't cool.
__________________
Maggie2021 is offline   Reply With Quote
Old 02-02-2022, 01:16 PM   #7
Junior Member
 
Brand: Thor Motor Coach
State: Florida
Posts: 10
THOR #21140
Quote:
Originally Posted by 16ACE27 View Post
As chance asked: both A/Cs? have you really verified everything else in the coach is powered? Furnace? Microwave? Etc?

There's more to this story....................
Thanks. Everything works fine on generator power including AC fans, microwave, etc. but the compressors won't turn on and therefore it doesn't cool.

Just to reiterate the AC's work fine on shore power.
__________________
Maggie2021 is offline   Reply With Quote
Old 02-02-2022, 01:24 PM   #8
Senior Member
 
Brand: Thor Motor Coach
Model: Miramar
State: California
Posts: 891
THOR #22927
Please be sure breakers are on at the generator.
__________________
Grumpy Grampa is offline   Reply With Quote
Old 02-02-2022, 02:17 PM   #9
Junior Member
 
Brand: Thor Motor Coach
State: Florida
Posts: 10
THOR #21140
Quote:
Originally Posted by Grumpy Grampa View Post
Please be sure breakers are on at the generator.

Thank you! The breaker on the generator is on and running other appliances. There is only one breaker on the Onan 6000 that I am aware of. For what it's worth I confirmed this with the Onan representative at the Tampa RV show.
__________________
Maggie2021 is offline   Reply With Quote
Old 02-02-2022, 02:43 PM   #10
Senior Member
 
Brand: Thor Motor Coach
State: Missouri
Posts: 2,324
THOR #6903
What does your amp loading show when running generator on each line? With AC fans on
__________________
lwmcguire is offline   Reply With Quote
Old 02-02-2022, 02:45 PM   #11
Junior Member
 
Brand: Thor Motor Coach
State: Florida
Posts: 10
THOR #21140
Quote:
Originally Posted by lwmcguire View Post
What does your amp loading show when running generator on each line? With AC fans on
Thank you. Where would I read the amp loading?
__________________
Maggie2021 is offline   Reply With Quote
Old 02-02-2022, 03:39 PM   #12
Site Team
 
16ACE27's Avatar
 
Brand: Thor Motor Coach
Model: ACE 27.1
State: Florida
Posts: 14,129
THOR #7035
Quote:
Originally Posted by Maggie2021 View Post
Thanks. Everything works fine on generator power including AC fans, microwave, etc. but the compressors won't turn on and therefore it doesn't cool.

Just to reiterate the AC's work fine on shore power.
Well, this makes no logical sense. The generator supplies 120 VAC power just like PS does, through 2 hot legs, a neutral, and a ground. The Automatic Transfer Switch (ATS) selects which source this power comes from and applies it directly to the power distribution center/breaker panel.

So if the A/C fans are running, the A/Cs are getting 120 VAC from the generator.

The thermostat(s) tell the A/Cs to run the fans and the compressors as needed to provide cooling. This control of the A/Cs by the thermostat's is done with 12 VDC control power. If the thermostat can control the fans then it has the control power to control the compressors, and the control power doesn't care if the 120 VAC side is coming from SP or the generator.

If you had some loose control power wiring that was subject to the generator vibrations you would think it would only affect 1 A/C, but maybe if you have a single thermostat and it was loose at the thermostat end it might affect both. I can't see any load shedding device affecting both A/Cs either.

In any case, it appears you do not have a simple problem and will require some hands-on troubleshooting in the coach to figure this one out. Let us know how it is resolved.
__________________
Ted & Melinda
2016 ACE 27.1
2016 Chevy Sonic Toad - Selling
2020 Chevy Colorado Z71 Trail Runner Toad
2024 Chevrolet Trax 2RS - Soon 2B TOAD
16ACE27 is offline   Reply With Quote
Old 02-02-2022, 04:19 PM   #13
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
Quote:
Originally Posted by Maggie2021 View Post
Thanks. Neither AC works on generator power. They work fine on shore power. The fans on the AC come on on generator power but not the compressors so it doesn't cool.

Quote:
Originally Posted by Maggie2021 View Post
Thank you! The breaker on the generator is on and running other appliances. There is only one breaker on the Onan 6000 that I am aware of. For what it's worth I confirmed this with the Onan representative at the Tampa RV show.

Thanks for clarification. And you are correct, the Onan 6000 Watt Diesel inverter generator is listed as having only one 30-Amp 2-pole breaker, so it should be all or nothing in power — unlike some generators that have two separate breakers and can trip +/- 50% of loads.

As far as I know, common air conditioners get power for fan/blower and for compressor from same 20-Amp breaker, so I agree with Ace that the generator appears to be supplying power to air conditioners circuits. Based on your observations, the only thing that makes sense to me is that “something” is telling the A/Cs not to run. It seems more of a control issue and not a power issue. It makes no sense, and can’t help with controls because motorhomes have become rolling computers, and I don’t know if it is possible for software to keep A/C compressors from running if generator is on.

By the way, you mentioned having an inverter, and I assume it’s wired as originally installed by Thor. If it’s aftermarket or someone rewired to revise operation, that introduces other possibilities. Sorry I can’t help at all. I would focus on control settings to see if there is a selection that prevents A/C from turning on when powered by generator.
__________________
Chance is offline   Reply With Quote
Old 02-02-2022, 04:31 PM   #14
Senior Member
 
Brand: Thor Motor Coach
State: Missouri
Posts: 2,324
THOR #6903
Quote:
Originally Posted by Maggie2021 View Post
Thank you. Where would I read the amp loading?
Not familiar with your coach but thought it probably had some kind of EMS panel, usually where or on the same as the inverter, charger and so on
__________________
lwmcguire is offline   Reply With Quote
Old 02-02-2022, 04:35 PM   #15
Senior Member
 
Brand: Thor Motor Coach
State: Missouri
Posts: 2,324
THOR #6903
On my Coach the EMS will limit the Heat Pumps or AC's depending on if dryer, range, fireplace, and so on so that neither side is overloaded

Here situation truly doesn't make sense but seems to be in the thermostats or load management

Will be interesting to hear what the final resolution is
__________________
lwmcguire is offline   Reply With Quote
Old 02-02-2022, 04:45 PM   #16
Site Team
 
EA37TS's Avatar
 
Brand: Entegra
Model: Accolade 37TS
State: South Dakota
Posts: 8,726
THOR #1469
Turn off the inverter and see if everything else runs runs on the generator.

Try that first.
__________________
EA37TS is offline   Reply With Quote
Old 02-04-2022, 12:59 PM   #17
Junior Member
 
Brand: Thor Motor Coach
State: Florida
Posts: 10
THOR #21140
Hi All!!

Thanks for all the feedback.

I'm happy and a bit embarrassed as it is now working and I have no idea why it wasn't.

I swear it wasn't working and I once again turned a bunch of switches(inverter on/off, disconnected batteries, turned breakers on/off) on and off and it started working again.

Thanks and sorry for the ambiguity.

Hopefully I won't trip whatever it was that triggered this in the past.
__________________
Maggie2021 is offline   Reply With Quote
Old 02-04-2022, 03:05 PM   #18
Site Team
 
16ACE27's Avatar
 
Brand: Thor Motor Coach
Model: ACE 27.1
State: Florida
Posts: 14,129
THOR #7035
Quote:
Originally Posted by Maggie2021 View Post
Hi All!!

Thanks for all the feedback.

I'm happy and a bit embarrassed as it is now working and I have no idea why it wasn't.

I swear it wasn't working and I once again turned a bunch of switches(inverter on/off, disconnected batteries, turned breakers on/off) on and off and it started working again.

Thanks and sorry for the ambiguity.

Hopefully I won't trip whatever it was that triggered this in the past.
Well, at least it's working now. No lessons learned but you gotta take what you can get.
__________________
Ted & Melinda
2016 ACE 27.1
2016 Chevy Sonic Toad - Selling
2020 Chevy Colorado Z71 Trail Runner Toad
2024 Chevrolet Trax 2RS - Soon 2B TOAD
16ACE27 is offline   Reply With Quote
Old 02-04-2022, 03:39 PM   #19
Senior Member
 
OldWEB's Avatar
 
Brand: Thor Motor Coach
Model: 2011 FW Hurricane 33T
State: England
Posts: 1,281
THOR #16471
I would like to point out that IF you had run the ACs on shore power then switched to the generator, you have to wait for the AC compressor to rest while its internal pressure drops, any refrigerant compressor needs this bleed down time as they are a low horsepower motor and cannot restart under pressure. The fan will still run... this protection is also in your S&B reefer.

They mostly use an overload on the compressor or some aftermarket electronics have the time delay built-in (SoftStartRV for one). So run the generator and wait... 5 - 15 minutes(?).
EDIT: NOW I read txc... mentions this in post #5.

SoftStartRV - Protection restart time interval: 3 minutes
__________________
OldWEB is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Thor Industries or any of its affiliates. This is an independent, unofficial site.




All times are GMT. The time now is 10:17 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2