Airstream Chat Room Airstream Links Campground & Product Reviews Airstream Classifieds Airstream Articles Blogs Photo Gallery Forum Listings Portal - Home Page

Go Back   Airstream Forums > Airstream Knowledgebase > Airstream Motorhome Forums > General Motorhome Topics




Check out our new sister site AirstreamCentral.com. To contribute an article click here.


Quick Links
- Forum Listings
- Register - it's FREE!
- View Member's Map
- Airstream Articles
- "Live" Chat Room
- View Classifieds
- Post a Classified
- Airstream @ eBay
- Upcoming Rallies
   - Add A Rally
- Rally Discussions
- Repair Discussions
- Search Forums
- Member List
- AIR # Directory
- Member Search
- Profile Photos
- Airstream Photo
- Airstream Links
- Fun & Games
- WBCCI Websites
- WBCCI Unit Forums
- Courtesy Parking
- Campgrounds
- Support & FAQs
- Community Policies
- Helpers Needed




Reply
 
Thread Tools Display Modes
Old 07-13-2005, 09:36 AM   #1
GlenCoombe
Rivet Master

GlenCoombe's Avatar
Profile:  Sumter , South Carolina
Posts: 1,359
Images: 25

Transfer Switch

I'm getting ready to install the Carrier Air V roof unit and then the Generac 40 Quitepac generator. As the old setup in the Champion was a manual twistlock pigtail that I had to change from generator to shore power I've not seen any transfer switch setups. I don't need automatic but would like to be able to switch over from my interior panel under the sofa. What am I looking for?
Also the coach had a generator switch on the panel that had the lettering covered over and it's never had a generator installed. Wonder if I can use it rather than the ugly Generac remote switch? Any ideas?
The coach is going to the dealer to begin it's repair and installation work the end of the week... your input is valuable to me, thanks
__________________
Glen Coombe AIR #8416
1984 28' Funeral Coach
Golf Professional Sales Rolling Showroom
"I'm not an expert. But I did sleep in an Airstream last night."
GlenCoombe is offline   Reply With Quote
Old 07-13-2005, 09:42 AM   #2
ALANSD
GA Airstreamer Air_005

Profile:  North , Georgia
Posts: 4,807

Not sure about your first question- but the generator switch on the control panel should be able to be wired to remotely start your gen. The panel pulls out and you can look at the wiring ti see if it is already got any wires attached to that switch or if it needs new. Either way if the switch is there it should work. It is sure convenient. Also there is an a/c monitor light on that panel, that should come on when shore power or generator are working.
__________________

Rallys twice a year..Lots of fun, food, and aluminum.

http://groups.yahoo.com/group/gaairstreamcampers/

http://airstreampassion.blogspot.com/

My Music Site:
HTTP://ALANDAVIDSONGS.COM
ALANSD is offline   Reply With Quote
Old 07-13-2005, 09:49 AM   #3
markdoane
Rivet Master
Profile:  , Minnesota
Posts: 4,521
Images: 59

I have a transfer switch that i got at Home Depot. The thing to watch out for is the circuit breaker rating. The 'off the shelf' units are limited to 15 amps, I don't know if that will handle your A/C.

http://www.airforums.com/forum...ead.php?t=9504
markdoane is offline   Reply With Quote
Old 07-13-2005, 10:21 AM   #4
87MH
Rivet Master

87MH's Avatar
Profile:  1978 31' Sovereign
Katy (West Planet Houston) , Texas
Posts: 1,760
Images: 215

Quote:
Originally Posted by GlenCoombe
... I don't need automatic but would like to be able to switch over from my interior panel under the sofa. What am I looking for?
Glen:

The 345's came with 2 automatic switches (definite purpose contactors).

One, mounted under the bed in the rear, switched automaticaly from shore power to generator. The other, mounted on the back of the generator enclosure (under the couch) automaticlay removed the "Rear AC" from the main selector switch - just like Lisa in "Green Acres", you can only use ONE "15" at a time - a manual switch above the cooktop in the 345 lets you select ONE and ONLY one "big amperage draw" (Front AC, Rear AC, Microwave, etc.) at a time.
With the generator running, the "second circuit" of the generator is dedicated(isolated) to the rear AC, allowing use of both the front and rear AC's together - only if the Generator is running.

The easiest thing, of course, for your 4 KW unit, would simply be to pick up a "relay" at an appliance/electrical contractor warehouse (commerical buildings use high amp contactor/switches in many applications), and automatically switch from shore power to generator power.

The "Champion Style" pigtail-manual-switch-it-over is certainly cheap and fool proof.
__________________
Dennis

"Suck it up, spend the bucks, do it right the first time."

WBCCI # 1113
AirForums #1737

Trailer '78 31' Sovereign Photos:'78 Sovereign Rebuild
Motorhome '87 Classic Motorhome Saga
87MH is offline   Reply With Quote
Old 08-02-2005, 07:28 PM   #5
pbnjsellers
2 Rivet Member
Profile:  Jarrettown , Pennsylvania
Posts: 58

Both airs?

87 MH, does that mean we can run both A/C units with only the generator running, or if the gen is running PLUS shore power?
pbnjsellers is offline   Reply With Quote
Old 08-03-2005, 07:12 AM   #6
87MH
Rivet Master

87MH's Avatar
Profile:  1978 31' Sovereign
Katy (West Planet Houston) , Texas
Posts: 1,760
Images: 215

Only on the GenSet

Quote:
Originally Posted by pbnjsellers
87 MH, does that mean we can run both A/C units with only the generator running, or if the gen is running PLUS shore power?
The electric feed cannot be "mixed" without circuit modification. I'll try to explain.

The 6500 watt Onan in the 345 has TWO legs (separate circuits)...

- one leg goes to the main cabin isolator (contactor) along with the shore electric hookup. This contactor switch feeds electricity to the main electric panel. How this works is after the shore power electric line enters the MoHo it does not go directly to the main panel...it (the shore power line) first goes through the "main definite contactor". This is a switch that has both the generator main leg AND the shore power electricity coming into it. This switch will allow either the Shore Power ONLY or the Generator Power ONLY to go to the main panel...this prevents both the shore electric from feeding into the generator coils and the generator current from feeding into the shore power line (or powering up the exposed shore power plug while it is in storage). This contactor (GenSet/Shore Power Switch) works by sensing power (voltage) from the GenSet. When the GenSet is not operating the switch does not sense voltage from the generator, and the contacts are "at rest", and closed (switched) to the shore power - allowing the shore power line to feed into the main electric panel...this is the "normal" operation. When the contactor switch senses voltage from the generator for about two minutes (this is a "smart" switch - it delays the "switch" to make sure the generator has enough time to warm up) it (the contactor) switches the electric source to the main panel FROM the Shore Power feed TO the GenSet Power feed. So, this contactor makes sure the main panel is fed from one of two sources (the shore feed or the generator), and also makes sure the voltage/current from the two sources are never combined together. This contactor switch is located under the bed of the 345.

- the other leg from the generator (the second leg) goes to a similar definite purpose contactor (this one located on the cabin side of the generator enclosure on the 345). This contactor works in a similar fashion to the main power feed, except it feeds only the rear AC - the contactor breaks the circuit from the main panel/main selector feed and allows current ONLY from the genset secondary circuit to go ONLY to the rear AC.

Hope this helps - PM me if you require more detail on the operation.
__________________
Dennis

"Suck it up, spend the bucks, do it right the first time."

WBCCI # 1113
AirForums #1737

Trailer '78 31' Sovereign Photos:'78 Sovereign Rebuild
Motorhome '87 Classic Motorhome Saga
87MH is offline   Reply With Quote
Old 10-18-2008, 09:58 PM   #7
smokepole1
New Member
Profile:  Kentwood , Louisiana
Posts: 1

345 Relays

87 MH.
Do you or could you supply a wiring diagram as tom how these two relays are wired? I think I messed up thinking that the shore feed wire from the j box by the reel fed directly to the panel above bed. I disconnected and ran a new wire to the panel and now when on generator power, I have no power to selector above range nor to panel above bed. I think I can correct but diagram would be very helpful. Thanks, Smokepole1
smokepole1 is offline   Reply With Quote
Old 10-20-2008, 08:17 AM   #8
bkahler
Rivet Master

bkahler's Avatar

Profile:  Jefferson , Arkansas
Posts: 654

Quote:
Originally Posted by smokepole1 View Post
87 MH.
Do you or could you supply a wiring diagram as tom how these two relays are wired? I think I messed up thinking that the shore feed wire from the j box by the reel fed directly to the panel above bed. I disconnected and ran a new wire to the panel and now when on generator power, I have no power to selector above range nor to panel above bed. I think I can correct but diagram would be very helpful. Thanks, Smokepole1
Here is a link describing how the 120vac wiring is laid out in our 1984 310 Motorhome. Other than the physical parts location its wired the same as in the 345 motorhomes.

Airstream motorhome 120vac operation

Hope this helps.

Brad
__________________
"Wherever you go... there you are." - Buckaroo Banzai

Air forums # 1674
1984 310 Limited Motorhome
1974 31' Excella 500 (future hauler for 2 Triumph race cars)
1974 20' Argosy Motorhome (future Excella 500 tow vehicle)
bkahler is offline   Reply With Quote
Old 11-09-2008, 08:54 PM   #9
blkmagikca
2 Rivet Member

blkmagikca's Avatar
Profile:  Nepean , Ontario
Posts: 84

I had posted this drawing previously, which should answer some of the queries about transfer switches.

http://www.vsquare.com/howard/photos...lectric002.jpg

This circuit was used to modify the existing 30-amp shore power of my '94LY to what is referred to as 50-amp. It really is 2 legs of a 115-115 volt (230volt) power, just like what you have coming into your house.

What you have to know is that there are 60-second time-delay relays used in this circuit (which is the rewiring of the 2 ATS switches in my '94LY) which are critical to prevent damage to you rig. When your generator starts, it is not immediately ready to deliver full power, so the mechanism that ensures that you don't attempt to inadvertently start your microwave or other 120-volt appliance before full power is actually available. FYI, I did, at one time, source these time-delay relays - they are not all that costly - just $10 each.

The shore power cord needs to be 4-wire, but you do not have to up the thickness or gauge, as the amperage stays the same (30 amps on one leg), just the voltage is increased.

If you look around at some of the surplus electric suppliers, you may be able to luck out (as I did) and get a 100-foot length of the stuff - I no longer have to carry extra heavy extension cords.

We did this modification about 2 or 3 years ago, and it has worked flawlessly.

I would STRONGLY recommend that you have an trained and certified electrician do the work, as there may be insurance issues if there is an error made. The person who designed this modification, who designs and builds industrial equipment used in the food industry, also contacted CSA to get verbal assurances that what he designed was valid and not in contravention of any standards. I cannot stress the importance of this, as you may otherwise invalidate your insurance.

Howard
__________________
WBCCI #5957
VE3JDZ
1994 Land Yacht 34 diesel
blkmagikca is offline   Reply With Quote
Reply


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

Similar Threads
Thread Thread Starter Forum Replies Last Post
2 speed wiper switch has no low speed rdm Mechanics Corner - Engines, Transmission & More... 6 01-09-2003 09:47 PM
igniton switch and the mystery of the dead battery Curtis-79MH Airstream Motorhome Forums 3 10-25-2002 03:58 PM
Rotary Light Switch 74SovereignInt. Electrical - Systems, Generators, Batteries & Solar 20 10-15-2002 07:31 PM
What the heck is that switch on the wall??? TRAPEZE Airstream Motorhome Forums 7 09-10-2002 05:05 AM
New battery selector switch FrankR Electrical - Systems, Generators, Batteries & Solar 0 03-27-2002 11:29 PM

Powered by vBadvanced CMPS v3.0.1

All times are GMT -6. The time now is 12:25 AM.

Other Social Knowledge forum communities:
Cooking Forum - Sailing Forum - Early Retirement - Airstream Trailer - Aquarium Forum - Royal Forum - Book Forum - Volkswagen Touareg Forum - Jeep Wrangler Forum - Whitewater Kayaking & Rafting Forum - Fiberglass RV Forum - RV Forum - Truck Conversion - U2 Music Forum
Social Knowledge Networks
Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2009, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.2.0

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.



eXTReMe Tracker

Other recommended RV/Travel Trailer sites:
Airstream Classifieds - Airstream Central - Airstream Photos - Fiberglass RV Forum - iRV2 RV Forum