Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-30-2012, 07:26 PM   #15
Rivet Master
 
Gene's Avatar
 
2008 25' Safari FB SE
Grand Junction , Colorado
Join Date: Sep 2007
Posts: 10,840
Electric ranges are 50 amp and 240 volts. Dryers are 30 amps and 240 v.

Regardless of that, once you eliminate one of the 2 hot wires of a 240 v. circuit, you would have a 120 v. circuit and half the amps too (I think, Lew will correct me). Depending on the rating of the receptacle, I would think that would be either 25 amps or 15 amps. 15 is too low for the A/C.

I don't think a dog bone for 50 amp to 30 amp has the right lugs for a 30 amp dryer receptacle. Every receptacle and plug has a specific pattern for each voltage and amperage so you don't plug the wrong thing into the wrong receptacle.

If you decide this is brain damage material, hire an electrician, but make sure the electrician knows what a 120 v., 30 amp RV plug looks like. They are hard to find sometimes and some electricians, even ones with licenses, don't know what they are or what they look like.

Three photos below: the one on the left is a 30 amp, 240 v. dryer receptacle, the one on the right is an RV 30 amp., 120 v. receptacle and the one on the bottom is a 50 amp, 240 v. range rec.

Gene
Attached Images
   
__________________

__________________
Gene is offline   Reply With Quote
Old 07-30-2012, 09:59 PM   #16
Rivet Master
 
TG Twinkie's Avatar
 
1974 Argosy 26
Morrill , Nebraska
Join Date: Nov 2009
Posts: 5,140
Images: 2
Blog Entries: 5
A 50 amp stove receptacle has 50 amp capacity on each of the 120 volt legs. Thus the requirement for #6 copper wire to feed it. A 30 amp dryer receptacle has 30 amp capacity on each 120 volt leg. Thus the requirement of at least #10 wire.
If you look at the double pole circuit breaker in the panel providing power to either of the above. You will note that whether it is 30 or 50 amps that number is on each of the circuit breaker handles. Not half as mentioned above.
__________________

__________________
Knowledge: "A gift to be shared. A treasure to receive."
TG Twinkie is offline   Reply With Quote
Old 07-30-2012, 10:07 PM   #17
Rivet Master
 
TG Twinkie's Avatar
 
1974 Argosy 26
Morrill , Nebraska
Join Date: Nov 2009
Posts: 5,140
Images: 2
Blog Entries: 5
In the photos that Crawford Gene posted. They show up 3 abreast on my iPod. The one in the center is the 30 amp 120 volt receptacle designed for travel trailers.
Zoom in on it and it is clearly marked "For Travel Trailer Use Only".
It also is clearly marked "120 volts"
If you have an electrician install this. Make certain he/she understands that it is 120 volt; not 240 volt.
__________________
Knowledge: "A gift to be shared. A treasure to receive."
TG Twinkie is offline   Reply With Quote
Old 07-31-2012, 12:53 AM   #18
3 Rivet Member
 
Join Date: Feb 2012
Posts: 104
Images: 3
Quote:
Originally Posted by dkottum View Post
Howard, were you using the 50 amp to 30 amp adapter when your auto transfer switch burned out recently?

doug k
Tiger Run just put in new service at some of the older trailer spots which we had one. I started out on the 30A when it burned the contact the first time. I then put the adapter into the 50A service and sill no power. It was not until I read the responses to my post for help that I realized what was going on. So I put 20A power into the generator plug upfront to force the relay to change states upon which the power came back on. Then I changed back to the shore power plug which was still with the adapter in place. The current being fed to the trailer was not the issue at all put the current being drawn by the trailer through the ATS.

As I explained to Dan Snider at the factory: “As discussed my belief is that with electric refrigerator, electric hot water, A/C on, and lights on that when the AC compressor cycles on a few times the current spike overloads the relay contact surface and causes it to burn or otherwise carbonize interrupting the current flow. When this happens the trailer 110 just shuts off and will not restart. There are no breakers tripped at the trailer or the shore box. You cannot clear it until you plug into the generator connection at the front of the trailer causing the relay to change over (break the burned normally closed contact). Then you can go back to the shore plug and it will work again for a little while and fail.”

You can cause the ATS to fail at will without blowing a single breaker by following the above setup. With current being drawn by the refrigerator, hot water, converter and the A/C compressor cycling on and off it will burn just as shown in my picture of the relay contacts in other threads. The Parallax ATS switch is just a cheap China made relay not a heavier duty contactor found in all other ATS switches.

I left the old Parallax ATS at the dealer this morning and asked for a replacement. I am happy to pass it along to anyone wanting a spare if the factory provides it, but they already know I have upgraded it so I would guess not!
__________________
mtntime is offline   Reply With Quote
Old 07-31-2012, 11:49 AM   #19
Rivet Master
 
Gene's Avatar
 
2008 25' Safari FB SE
Grand Junction , Colorado
Join Date: Sep 2007
Posts: 10,840
Quote:
Originally Posted by TG Twinkie View Post
A 50 amp stove receptacle has 50 amp capacity on each of the 120 volt legs. Thus the requirement for #6 copper wire to feed it. A 30 amp dryer receptacle has 30 amp capacity on each 120 volt leg. Thus the requirement of at least #10 wire.
If you look at the double pole circuit breaker in the panel providing power to either of the above. You will note that whether it is 30 or 50 amps that number is on each of the circuit breaker handles. Not half as mentioned above.
TG, thanks for the correction. It makes sense now that you explain it.

The automatic transfer switch is a new thing. I am unsure what it does and why it wasn't needed on earlier models, or what was used in its place.

Gene
__________________
Gene is offline   Reply With Quote
Old 07-31-2012, 12:56 PM   #20
Rivet Master
 
dkottum's Avatar
 
2012 25' Flying Cloud
Battle Lake , Minnesota
Join Date: Jun 2009
Posts: 7,716
Gene, the auto transfer switch allows you to plug a generator (or campground power) into the front side of your trailer, as well as rear roadside. There is an additional receptacle on the front of the trailer.

Handy for those with big generators in the back of pickups. The ats automatically finds your chosen power source, but prevents two power sources at once.

doug k
__________________
dkottum is offline   Reply With Quote
Old 07-31-2012, 02:27 PM   #21
Rivet Master
 
Gene's Avatar
 
2008 25' Safari FB SE
Grand Junction , Colorado
Join Date: Sep 2007
Posts: 10,840
Thanks Doug. I got a PM on this too. Good idea, poor quality in the ATS is what I have been told. A simpler solution would be to have the shore power receptacle in the center of the trailer—closer to the truck bed and closer to many shore power pedestals.

Gene
__________________
Gene is offline   Reply With Quote
Old 07-31-2012, 03:38 PM   #22
Rivet Master
 
Skater's Avatar
 
1995 30' Excella
Bowie , Maryland
Join Date: Apr 2005
Posts: 2,344
Quote:
Originally Posted by CrawfordGene View Post
Thanks Doug. I got a PM on this too. Good idea, poor quality in the ATS is what I have been told. A simpler solution would be to have the shore power receptacle in the center of the trailer—closer to the truck bed and closer to many shore power pedestals.
...but still not practical for running a generator on the road, which was the point of the front hookup, I thought.
__________________
1995 Airstream Classic 30' Excella 1000
2014 Ram 2500 Crew Cab with Cummins 6.7L Diesel

Sold but not forgotten: 1991 Airstream B190
Sold: 2006 F-250 6.0L Powerstroke Supercab
Skater is offline   Reply With Quote
Old 07-31-2012, 04:18 PM   #23
Rivet Master
 
dkottum's Avatar
 
2012 25' Flying Cloud
Battle Lake , Minnesota
Join Date: Jun 2009
Posts: 7,716
No, the point is not to lift a heavy generator in and out of the pickup at each camping stop, or to reach some shore power pedestals without an extension cord. While on the roadway your tow vehicle provides the trailer with some battery charging power.

doug k
__________________
dkottum is offline   Reply With Quote
Old 07-31-2012, 04:44 PM   #24
Rivet Master
 
1988 25' Excella
1987 32' Excella
Knoxville , Tennessee
Join Date: Oct 2010
Posts: 2,164
Blog Entries: 1
"I carry a 50 to 30 amp adapter dog bone whenever I travel to unknown area. I got stuck in a campground five years ago where they only had 50 amp sites still available at 7:00PM and I had to buy one for $20. "

Good deal. I think mine was $40 or more and too late and remote to look for another campground. At one campground they would lend you one if you put up a 25 deposit. I have been in several campgrounds with just 50 amp. Never thought of it as a safety issue. I think one was a newer forest service campground with a few electric sites. Do they really run both hot wires to the outlet? Looks like they would save wire and just run the 3 necessary leads, and avoid the possibility of getting 220 also. Or do they think there will be 220 volt campers down the line? Or are there some now?
Thought about putting in a 30 amp, but we do not stay in it or run the air at home so we plug it into a 20 amp. I have run the air on that circut for an hour or so.

My guess is that if you get a short between the ATS and the breaker box you are pretty much out of luck whaterver amp service it is on.
__________________
Bill M. is online now   Reply With Quote
Old 08-09-2012, 09:11 PM   #25
Rivet Master
 
Currently Looking...
Sioux Falls , South Dakota
Join Date: Mar 2011
Posts: 843
I asked about when Airstream switched to 50A service, and was quite surprised to find that only those coaches with dual air conditioners have 50A service from the factory. Most have 30A service.

I'm not an electrician, but I've done quite a bit of electrical work, so maybe I can explain what's happening when someone (like most of us) with a coach wired for 30A is confronted with an electrical pedestal with only 50A service.

As has been previously mentioned, the 50A plug has four prongs, whereas the 30A one has only three. On the 30A plug those three are a hot, a neutral, and a ground. On a 50A plug there is an additional hot line, for a total of two hot prongs, a neutral, and a ground. If one measured the voltage between one hot wire and the neutral wire, one would find somewhere between 115 and 125 VAC. Measuring between the two hot lines would show approximately double that, 230 to 250 VAC.

When one is plugged into a 30A outlet, the maximum current that will be passed through the breaker is 30 amps, which is 3600 Watts (at 120 volts). The 50A outlet provides two circuits, each of 50 amps, or 6000 Watts each, for a total possible draw of 12,000 Watts. That's why the motor homes, with two, three, or even four air conditioners need the 50 A outlet.

So what happens when we need to plug into a 50A outlet, but our coach is wired for only 30A? We simply use only one side of the available service. The dog-bone adapter has the ground wire running from the ground prong to the ground slot, the neutral wire runs from the neutral prong to the neutral slot, and a hot wire runs from one hot prong to the hot slot. The second hot prong is not used.

At this point there is a possible 50 amps available to the coach, but the main breaker is only 30 amps. That means that if the coach attempts to draw more than 30 A, the coach's main breaker will trip. The breaker on the pedestal will NOT trip, because you haven't asked it to pass more than 50 A. A short in the dog-bone will trip the pedestal breaker, though.

Bill M, yes, there are some all-electric motor homes that have 220 V appliances. I haven't seen many Airstreams with washers and dryers in them, but they are pretty common in 5'ers and motor homes. Most of the dryers are 120 V units, and by all accounts take forever to dry a small load of clothes. The newest coaches are putting in small 220 V dryers.

BTW, last summer when we spent a night at the factory, we plugged into the 30A outlet, so our neighbor had to use a dog-bone to plug into the 50A one. That opened our eyes, and when we got home I bought a 50A to 30A dog-bone. We haven't needed it (yet) but I'd rather have it and not need it than need it and not have it.
__________________
David Lininger, kb0zke
TAC SD-6
AIR 54240
Heartland mpg 181 (sold)
1993 Foretravel U300 (for sale)
kb0zke is offline   Reply With Quote
Old 08-09-2012, 10:17 PM   #26
Rivet Master
 
dkottum's Avatar
 
2012 25' Flying Cloud
Battle Lake , Minnesota
Join Date: Jun 2009
Posts: 7,716
I'm uncomfortable with adapting my trailer to 50 amps (my background includes aircraft electrical systems and constr electrician) so I wouldn't do it. The power cable, trailer receptacle, auto transfer switch (new to 2012), and wiring to breaker panel are designed to carry 30 amps but protected by well-worn campground 50 amp breaker.

doug k
__________________
dkottum is offline   Reply With Quote
Old 08-10-2012, 07:39 AM   #27
Rivet Master
 
TG Twinkie's Avatar
 
1974 Argosy 26
Morrill , Nebraska
Join Date: Nov 2009
Posts: 5,140
Images: 2
Blog Entries: 5
One could build their own 50 to 30 amp adaptor that would protect all if the trailer wiring. Get a water tight box large enough for a 30 amp circuit breaker. Wire in a 50 amp cord (electric stove cord) to provide the power to the box. Install a 30 amp receptacle and wire it to the 30 amp circuit breaker. Plug the trailer into that receptacle.
It would be one more thing to carry. But if you are concerned about the proper protection, this would do it.
__________________
Knowledge: "A gift to be shared. A treasure to receive."
TG Twinkie is offline   Reply With Quote
Old 08-10-2012, 08:27 AM   #28
RLS
Rivet Master
 
RLS's Avatar

 
2004 25' Classic
Prescott , Arizona
Join Date: Jul 2008
Posts: 608
I was using the dog bone 30 to 50 amp adapter. Noticed when unpluging that the adapter and the end plug on our cord had melted some. This was in the winter time with 2 electric heaters going I took it apart and noticed how small the adapter pieces where. Decided it would be best to go with a 50 amp plug wired to my cord and when needed, I now use a 50 to 30 amp adapter. This has worked out really good with no more problems.
__________________

__________________
Julia & Bob
W/ Deedee & Boo
AIR #30685
RLS is offline   Reply With Quote
Reply


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



Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 07:44 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

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