Diagrams and pictures on how the transfer switch contactors work - Luxury Coach Lifestyles
Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
Reply
 
Thread Tools Display Modes
 
Old 08-27-2008, 01:22 AM   #1
encantotom
Senior Member
 
encantotom's Avatar
 
Join Date: Mar 2007
Location: mesa, az
Posts: 1,375
Smile Diagrams and pictures on how the transfer switch contactors work

hi,

i did this for another thread but thought it might be easier to find if it was it's own topic. i had a buzzing contactor when plugged into shore power, so i bought new replacement ones from grainger and installed them along with new neon indicator lights. the new ones were different in looks and how the add on switches were attached but function identically as they are the newer versions of the old ones. they are quite pricey as i paid under a hundred bucks apiece for them. i tried my best to sketch how they are hooked up so it is easy to read. it is accurate i believe.

here is how my box is set up. it is the box in the electrical bay at the back of the coach. the first picture is the old contactors and the second picture is the new ones with new indicator lights. you can see i am only plugged into 30amp now when i just took this picture as only the green lights are on. (you can see them glow).



here is the picture of the new contactors and new neon lights.



so, i replaced the indicator lights with linrose 120v ac pilot lights on the box in the electrical bay where the contactors are. i traced the wiring out on them and at least on my coach they only work when ground power is plugged in and on. i put green for the 120v and amber for the 240 and red for the polarity. the green is Linrose part number B2112A5. about 3 bucks apiece.

when plugged into my house power (15amp 120v), the two green 120v lights come on. of course the adapter plug shoots 120v to both legs so that makes sense. the 240 lights will only come on when you are plugged into a 50amp source.



again, it you look at how they are wired, they only come on when connected to shore power. no matter what position the gen/shore switch is in because they are powered off the incoming power.

the indicator lights in the coach are powered off of both shore and gen power.

the fuse with the red wires on it take power from the shore incoming power anytime there is power applied and sends it to the switch up by the driver. when the switch is in the shore position it routes that 120v back to the box in the bay (red with black stripe) and goes to the normally closed aux switch on the contactor for the generator (which if closed, would route the 120v through it over to the solenoid power to energize the shore power contactor. so the only way the shore power contactor can be engergized is if the generator contactor is not energized.

the fuse with the black wire on it does the same for the generator switch in the cockpit. anytime the generator is running there is 120v to the fuse headed up to the cockpit switch. when you put the switch in the generator position, the 120v is routed back on the black with white stripe wire to the contactor box where it heads to the aux switch on the shore power contactor. if the shore power contactor is not energized, it will allow the 120v through the switch to power the solenoid on the generator contactor.

pretty cool how they made sure you could not power from both. just like a generator transfer switch for a house only a bit more elegant.

i plan on updating this with the wiring for the meters and indicators lights that are up by the driver at some point.

the contactors are just solenoids, so if you leave your coach plugged in for long periods of time like mine, they just wear out and start buzzing. the new contactors are different looking than the old ones and require the add on switch i refer to in the diagram. the old ones have it, but it is obscurely hidden inside the contactor and is much different looking.

my coach has an Electrical Management System that is wired between the shorepower cord and the contactor box to stop bad power from causing any problems. an EMS HW-50b....the newest is the 50c. this i did not show in the wiring diagram. it has a control panel that tells the status of L1 and L2 by giving volts, amps and hertz along with an error code if there is any problem.

keep in mind this is for my 1990 and yours may be different., Michael Days is the same, so it is good for a couple of years at least.

also, as usual, no guarantees on accuracy, this is 120volts, so be very careful when working with it. disconnect everything including the invertor to be sure there is no AC anywhere that can find its way to your fingers.

tom
__________________

__________________
2002 45'8" Coach
2008 Honda CRV toad

https://www.newellclassic.com/forum/album.php?albumid=8
encantotom is offline   Reply With Quote
Old 08-27-2008, 01:47 AM   #2
fulltiming
Senior Member
 
fulltiming's Avatar
 
Join Date: Feb 2006
Location: Texas
Posts: 1,558
Default

Thanks Tom. This is a great information source as tracking down the wiring is always the biggest chore of any electrical project.

I have replaced my auxiliary contactors but not the primaries. I would suggest that anyone finding themselves in a situation where either shore power or generator power doesn't come on take a look at their auxiliary contactors to see if they have dirt in them. The power bay in my coach picks up a lot of dirt when traveling or parked on dirt or sand. If a small amount of debris gets into the opening in the auxiliary contactor, the points will not close the circuit and that will not allow the main relay to actuate.
__________________

__________________
Michael and Georgia Day
1992 Newell 43.5' #281
8V92 DDEC-2, HT740
PT Cruiser GT with Remco Transmission Pump
https://newellowner.com/newell-photos/
fulltiming is offline   Reply With Quote
Old 08-27-2008, 01:25 PM   #3
Richard and Rhonda
Senior Member
 
Richard and Rhonda's Avatar
 
Join Date: Oct 2007
Location: Huntington WV
Posts: 1,041
Default

Fantastic Post, Thank you. Very helpful for future searchers of info.
__________________
Richard Rhonda Ty and Alex Entrekin
1995 Newell # 390 DD Series 60, Allison World Trans
Subaru Outback toad
CoMotion Tandem
Often wrong, but seldom in doubt
Rhonda's chronicle https://wersquared.wordpress.com/
Richard and Rhonda 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

Forum Jump

» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Newell Coach Corporation or any of its affiliates. This is an independent, unofficial site.


All times are GMT. The time now is 09:45 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
×