Bus Conversion Magazine Bulletin Board
April 19, 2018, 07:11:12 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: If you had an Online Subscription:  It will not get lost in the mail.
   Home   Help Forum Rules Search Calendar Login Register BCM Home Page Contact BCM  
Pages: 1 [2]  All   Go Down
Author Topic: 50A shore cable a/c question  (Read 4382 times)
Buffalo SpaceShip
Hero Member
Offline Offline

Posts: 591

« Reply #15 on: August 02, 2007, 11:21:15 PM »

Well, a L1430c is a 30A connector. How is the 50a dogbone or extension feeding this plug? You likely have some reverse-polarity going on at the L1430c that the 50a extension rectifies. If you go to your panel, each A/C is on a different leg. On the A/C that doesn't work w/o the extension, measure the voltage from hot to neutral and ground with each condition (with and without 50a extension). You'll likely find that voltage is zero from hot to neutral w/o the extension... and/or you'll find voltage across neutral and ground which points back to the mis-wired L1430c plug.

Considering the wiring of your coach, you likely don't have a separate grounding bus bar on your panel, which should trip the breaker when current travels through the ground wire. These are the bonding issues I spoke about previously.

And yes, something is broke.  Wink Time to fix it! Grin

Brian B.

Brian Brown
4108-216 w/ V730
Longmont, CO
Hero Member
Offline Offline

Posts: 2585

'85 Neoplan Spaceliner "Odyssey"


« Reply #16 on: August 02, 2007, 11:37:17 PM »


You are not the only one getting more confused by the minute....

You've written several times that you have a 50-amp shore cord, and a 50-amp extension cord.  But now you are telling us that the 50-amp cord connects to your bus with an L14-30, which is a termination that is only rated for 30 amps.  Between that and the generator-shore parallel connection with no switching, I have to say that your entire electrical system is suspect, and I don't think we can make any assumptions at all about it without a good, thorough inspection.

Probably not what you want to hear, but I would start by addressing some of these major deficiencies, and trying to diagram out just exactly what you have.  With things as mis-wired as they are, there is no telling what sort of results you will get from any shore connection arrangement at all.

Right off the bat, I would (1) remove the shore and generator parallel connection, either by installing a transfer switch (manual or automatic), or by installing a 50-amp receptacle on the generator and using the shore cord itself to make the switch and (2) replace the L14-30 with a proper 50-amp connector.  Then I would meter out all your cords and adapters to make certain they are properly wired.  Once that's done, you will have a good starting point to diagnose the A/C problem.

All that said, I am sticking with my theory that the shore cord is not making good contact with the dogbone, but the extension cord makes good contact at both ends.  Your meter may show good voltage, but that is at a no-load state -- adding a load can cause significant voltage drop over a marginal connection, enough so that the A/C will not start.  (Running through the under-sized connector is not helping this situation any.)


Full-timing in a 1985 Neoplan Spaceliner since 2004.
Our blog: http://OurOdyssey.BlogSpot.com
Some Assembly Required
Hero Member
Offline Offline

Posts: 4093

Slightly modified 1982 MC9


« Reply #17 on: August 03, 2007, 08:07:15 AM »

I'm with Sean on this one.  I think it's a matter of not getting a good connection between the dogbone and the shore cord.

I'd really like to see some photos of all the ends of the cords. Especially the 50 amp extension cord. What are you using for a female end on that one, since I've not been able to find a replacement plug for that one yet.

As indicated by Brian, the dogbone crosses the incoming 30 amp hot to the two 50 amp conductors in the output, so both hots in your 50 amp (30 amp??) extension and shore cords should be hot, regardless whether the extension is in or not. It's possible  you have two wiring issues, one in the shore cord, and one in the extension, which are canceling each other out. That's a scary thought, because it could mean a neutral or safety ground is miswired in the shore cord, and the extension was wired to make the shore cord work.


Craig Shepard
Located in Minnesquito

http://bus.gumpydog.com - "Some Assembly Required"
Hero Member
Offline Offline

Posts: 1184

« Reply #18 on: August 03, 2007, 08:18:35 PM »

Craig, Sean, Brian and Jack, etc. 

the 50a extension is a std molded end at each end.  so is the dogbone.  CampWorld specials.  the 30 or 50 amp cable with the l1430 to the bus male receptacle is homemade and has the 4 prong standard 50a connector.  since i drove over and squashed it, then replaced the shore end, i guess that cable end is suspect.  the 30A extension is also a homemade that i think i replaced ends on. and finally, i'm the one that put a 30A breaker in the garage and the receptacle outside for the bus.
i'm trying to figure out hubble or marinco receptacle and female cable end.  i've been looking at 50a, 120/250v ends.  geesh, are they expensive.  at an electrical supply house, a stove receptacle in the bus and the 4 prong male for the cable would only be $35, but i suppose a male on each end of the cable violates all sorts of safety rules and NEC., so i didn't buy it but i sure don't understand the extra $150 for the "correct" ones from campworld or west marine.
as i said b4, this is and has been a learning experience.  We will get this fixed soon even though it's sort of working.  i do understand accidents waiting to happen and i don't want to be one.  any comments as to best brand for transfer switch.  a couple generac 100a on ebay for around $300, with a panel that i don't think i need.

1991 Eagle 15 and proud of it.
8V92T, 740, Fulltime working on the road.

Fran was called to a higher duty 12/16/13. I lost my life navigator.
Pages: 1 [2]  All   Go Up
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!