If you are old enough, you will remember the time when a Shore Power Cord was just an extension cord. It mostly just fed a small 20A converter/charger for the 12V needs, although a 15A was the standard hook-up in most campgrounds for a long time.
With the larger campers and motorhomes came the 30A line. You always needed to carry a conversion adaptor because 30A service was not always supplied in many campgrounds.
All those smaller lines consisting of #12 or #10 wire were thin and flexible enough to keep attached to the camper. Some were spring-loaded and would feed through a hole in the side, into a spool to a load-cen-ter or transfer switch, if the camper came with a generator.
Some motorhomes, including the relatively expensive GMC motorhome did not have automatic transfer switches and used a plug-over, where the connection was changed manually from shore power to generator power. Automatic transfer switches were expensive and not very reliable in the beginning.
In 1994 I started on my Eagle conversion. This was around the time most larger RV’s had 50A service. Due to the fact that I had a bad experience with the transfer switch in my Fleetwood LTD, I installed a manual transfer switch from W.W. Grainger. Coiling a #6 line up in cold weather is like trying to coil up a 30’ 2×4….LOL. Therefore, the only option was to just lay it inside one of the luggage compartments.
Lines that could be disconnected were already being used, but there was no real standard or various connectors in use. 50A shore-power was used in boating a long time before it was available in RV use. My1979 48’ Morgan sailboat had electric heat and A/C be-cause large live-on-board boats were in need of constant power supply. My Morgan had a 100A service using twin 50A lines. I always liked the way they connected to the hull. I liked it enough to use the same connection on my Eagle and all of my buses.
There was nothing to Google in the beginning. Bus Conversion Magazine had just came out in 1992 on newspaper print like toilet paper. All the information came from the FMCA magazine and very little from other publications. Also, my friend Bill Lowman, (RIP) wrote the book How to Convert Buses into Motorhomes, which was very helpful.
Camping World was very little help and expensive. From the boating days, I knew about West Marine and they are much better equipped for bus conversion needs. Through my construction business, I opened up an account with Port Supplies, a division of West Marine, for a large discount on all their parts and equipment.
Like I said, I used the marine style disconnects on all of my buses, but there were no lines available
in the boat/RV combination. RVs use straight plugs and boats use twist-locks; that combination was not available and I had to make it up by using a #6 AWG service cord, and attaching the different plugs on each end. I remember it was expensive, especially the marine inlet connection on the bus.
Approximately one year ago, my landline that I use to power my Dina in my shop failed. The female plug shorted out and needed to be replaced. I thought, “No big deal”, and called Port Supply. I have not bought anything from them in quite some time and I was no longer in their system. I went online to check the availability at West Marine. Yes, they carried the needed plug, which cost $124.99 plus tax. Thank God for Google. I continued to keep looking on line and found that same plug for half the price.
My biggest surprise was that the cord was now available in the needed twist-lock R/V combination cord. Those cords average in price for less than the $124.99 from West Marine. I ended up buying a 30’ cord from Amazon for $76.99, including tax and shipping.
This cord is really handy because it has a handle on the straight plug to pull it out of the receptacle. There is no need to wiggle the plug or use a screwdriver to pull it off like some of the older plugs..
Shore Power Cords have improved over the years and have become safer over time. No matter what cord you decide to use, be sure it is large enough to carry the load and wired properly for an RV. A good book available from Bus Conversion Magazine is Bus Wiring for Bus Nuts by Dave Galey. This book is available free for all BCM subscribers.
Editors Note: Shore Power Cords have improved over the years and have become safer over time. No matter what cord you decide to use, be sure it is large enough to carry the load and wired properly for an RV.
A good book on this subject is available from Bus Conversion Magazine is Bus Wiring for Bus Nuts by Dave Galey. This book is available free for all BCM subscribers.