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

Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 06-04-2023, 10:20 AM   #1
Junior Member
 
Join Date: Jul 2016
Posts: 3
Allegro bus Onan Transfer switch problem

I have a 1997 40' allegro Bus
When i crank 7500 quiet generator
runs normal and then idles down and does not power RV.
shore power works fine.
no breakers are flipped, have tripped breaker om Gen and reset.
same results when disconnected from shore power or Hooked up.
Any suggestions?
MVaughn1 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 06-04-2023, 10:26 AM   #2
Senior Member
 
Join Date: Oct 2014
Posts: 7,867
Mvaughn1,


Welcome to iRV2.


Start by turning OFF and back ON the on-generator breakers.


After that, if you are safe working around 120 VAC, remove the lid to the ATS and check for power IN and OUT with the generator on.
__________________
Brett Wolfe
Ex: 2003 Alpine 38FDDS. Ex: 1997 Safari Sahara. Ex: 1993 Foretravel U240
wolfe10 is offline   Reply With Quote
Old 06-04-2023, 11:05 AM   #3
Junior Member
 
Join Date: Jul 2016
Posts: 3
Thank you Wolfe10
I am comfortable with 120 volts.
have reset breakers several times but i need to understand how this works.
Does the Generator cable go the Transfer switch or is that just where the relays stop the passing on of shore power?
MVaughn1 is offline   Reply With Quote
Old 06-04-2023, 11:09 AM   #4
Senior Member
 
Join Date: Oct 2014
Posts: 7,867
The ATS has input from both shore power and generator. It allows only one source of 120 VAC at a time into the coach.


Remove the lid and you will see the two IN's and the one OUT that goes to the coach main 120 VAC breaker box.


If no 120 VAC with the generator running on the IN side of the ATS, there is a junction box where generator wiring connects to the cable that goes to the ATS.
__________________
Brett Wolfe
Ex: 2003 Alpine 38FDDS. Ex: 1997 Safari Sahara. Ex: 1993 Foretravel U240
wolfe10 is offline   Reply With Quote
Old 06-04-2023, 11:27 AM   #5
Senior Member
 
Skip426's Avatar


 
Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 31,269
Here's a picture of my transfer switch with the lid off .

Grey cable at the bottom is genset power .
Red arrows indicate the contactors for gen set and shore power .
Green led indicates proper operation .
With all power removed you can press on the black portion indicated by the arrows , hold it in and check continuity through the switch .

EDIT: If your transfer switch is considerably different than this photo , please post a picture and make/model info .
Attached Thumbnails
Click image for larger version

Name:	IMG_0135 (480x640).jpg
Views:	28
Size:	141.4 KB
ID:	394464  
__________________
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 06-05-2023, 07:01 AM   #6
Junior Member
 
Join Date: Jul 2016
Posts: 3
My ATS is still original. PS-245S Power Switch
Todd Engineering.
With Gen running i can flip breaker off on shore power and one coil activates. Green light comes on with Gen. second coil never activates. I can manually make it contact and it makes everything work.
my switch says it has 110 volt DC coils. looks like we have 150 volts dc across coils
pretty sure coil is out, but any idea on the 150 v dc
MVaughn1 is offline   Reply With Quote
Old 06-05-2023, 07:29 AM   #7
Senior Member
 
MN_Traveler's Avatar
 
Join Date: Apr 2012
Location: Louisville, KY
Posts: 1,395
If you have 120v from the generator, and you can manually activate the generator supply switch (with power going to the coach), then i would just suspect an old, broken ATS. you will likely need to replace it
__________________
- 2017 Newmar London Aire -
MN_Traveler is offline   Reply With Quote
Old 06-05-2023, 07:31 AM   #8
Senior Member
 
Join Date: Nov 2018
Location: Beaver Dam, Wisconsin
Posts: 5,038
Quote:
Originally Posted by MVaughn1 View Post
I have a 1997 40' allegro Bus
When i crank 7500 quiet generator
runs normal and then idles down and does not power RV.
shore power works fine.
no breakers are flipped, have tripped breaker om Gen and reset.
same results when disconnected from shore power or Hooked up.
Any suggestions?
Possibly an Onan 7500 quiet generator 7.5 HDKAT-41934. See serial number label for correct model number.

It should probably maintain a constant RPM. It probably should not "idles down".

Get Operator's Manual from Cummins. You need an account.
https://www.cummins.com/cm-generator-manuals

Find troubleshooting section and diagnose the issue.
__________________
Paul Bristol
Kodiak Cub 176RD
Nissan Pathfinder 2015
Persistent is offline   Reply With Quote
Old 06-05-2023, 10:15 AM   #9
Senior Member
 
Skip426's Avatar


 
Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 31,269
Quote:
Originally Posted by MVaughn1 View Post
My ATS is still original. PS-245S Power Switch
Todd Engineering.
With Gen running i can flip breaker off on shore power and one coil activates. Green light comes on with Gen. second coil never activates. I can manually make it contact and it makes everything work.
my switch says it has 110 volt DC coils. looks like we have 150 volts dc across coils
pretty sure coil is out, but any idea on the 150 v dc
Todd Engineering went under in 2008 , so parts maybe a problem .

Here's a document on testing the contractors , using an ohm meter .
Attached Files
File Type: pdf Todd wiring and Repai).pdf (225.3 KB, 8 views)
__________________
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 06-05-2023, 11:24 AM   #10
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Join Date: Jan 2000
Location: West Palm Beach, FL. USA
Posts: 27,519
Quote:
Originally Posted by Persistent View Post
Possibly an Onan 7500 quiet generator 7.5 HDKAT-41934. See serial number label for correct model number.

It should probably maintain a constant RPM. It probably should not "idles down".

Get Operator's Manual from Cummins. You need an account.
https://www.cummins.com/cm-generator-manuals

Find troubleshooting section and diagnose the issue.

The Onan7500 is an inverter-generator and thus variable speed rather than fixed RPM. It revs up or down to match the amp load.
__________________
Gary Brinck
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL
Gary RVRoamer is offline   Reply With Quote
Old 06-05-2023, 02:19 PM   #11
Senior Member
 
Join Date: Jul 2014
Posts: 35,317
Your transfer switch has 2 relays, one for switching the neutrals and the other for switching the hot lines.
Both contactors need to pull in.

Time to modernize , replace it.
Click image for larger version

Name:	Screenshot_20230605-161544_Chrome.jpg
Views:	22
Size:	43.9 KB
ID:	394549
twinboat is offline   Reply With Quote
Reply

Tags
allegro, allegro bus, onan, problem, switch, transfer switch



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
2021 Tiffin Allegro Bus 45OPP - Transfer Switch location GUS2000 Tiffin Owner's Forum 6 10-30-2020 04:41 AM
2015 Allegro Bus 45 Transfer Switch Ddcouple Tiffin Owner's Forum 3 03-26-2019 07:36 AM
Transfer switch didn't transfer/switch jimmy braden Class A Motorhome Discussions 29 06-03-2018 11:04 AM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 05:55 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.