Shore power upgrade / safety issue close call

[richard5933]

Spent today running new shore power feed to the manual transfer switch.

Custom Coach had installed an old-style Hubbell receptacle using 8/3 cable (shell/chassis served as ground). The wiring they used was not suitable for 50-amp service, and I wanted to have a proper grounding buss bar. Strangely, Custom Coach used the proper 6awg wire between the transfer switch and the breaker panel. They only used the 8awg between the receptacle and the transfer switch.

Installed a new Marinco stainless 50-amp receptacle and connected it to the transfer switch using 6/4 cable. A proper grounding buss bar is in place, and now I can start the process of separating neutral from ground on all the outlet circuits. (They installed some with bonded neutral/ground.)

What sparked all this were two things - first was seeing photos of an MC8 with burnt wiring from some old damage. Second motivation was a slightly warm receptacle last week. Did a voltage check and saw that I had 120vac outside the receptacle and only 117vac at the breaker panel. My guess was that the missing voltage was going to make the heat.

Good thing I did this - when I removed the old 8/3 cable I saw that the insulation was hard and brittle, and pieces of it broke away as I removed it. Wouldn't have been long till I had big problems. Seems like that stretch of 8/3 had been getting warm for a while.

Lesson? If you have an older conversion or didn't do the work yourself, be sure to check your shore power feed lines and connections.

[luvrbus]

Most people are changing to the Smart Plug , new boats and Rv's with 50 amp service are using the Smart Plug now a little on the pricey side but a good plug I just install one on my RV I got tired of replacing the twist and lock Marinco

[richard5933]

I saw those and almost went that route. Only thing that kept me with the Marinco is availability of replacement parts and power cords. You know that when I need something it will be in the middle of nowhere that doesn't have the new style.

[Lin]

Don Fairchild owner a Country Coach conversion.  He always said that they skimped on wire size.

[richard5933]

Don Fairchild owner a Country Coach conversion.  He always said that they skimped on wire size.

That's an understatement. True, but an understatement.

[chessie4905]

Coach conversion business was a learning process back then. Some of the issues with wire coverings took years to show deterioration. On our 4104, the 2 ought or whatever wire size that went from  12k Kohler generator to the 2 8d batteries had the insulation cracking and falling off exposing the stranded copper. And not little pieces, but big chunks. Some was from heat from generator compartment. At first, I covered it with 2 layers of shrink tubing, but then noticed it was doing it in places clear back to batteries. Of course, I replaced the whole length. I was extremely lucky we didn't encounter a massive short and fire. This conversion was done by one of known big converters back then and are still in the business. Our conversion was one of their first ones. Who knew back then?Overheated main wiring plugs and sockets is still a problem to this day. Ask any of the rv owners. Add in corrosion, dirt, and looseness to connections. An ir gun is helpful to scan the plugs and sockets while in use quick and easy enough. And don't forget to disconnect before leaving😉

[richard5933]

Coach conversion business was a learning process back then. Some of the issues with wire coverings took years to show deterioration. On our 4104, the 2 ought or whatever wire size that went from  12k Kohler generator to the 2 8d batteries had the insulation cracking and falling off exposing the stranded copper. And not little pieces, but big chunks. Some was from heat from generator compartment. At first, I covered it with 2 layers of shrink tubing, but then noticed it was doing it in places clear back to batteries. Of course, I replaced the whole length. I was extremely lucky we didn't encounter a massive short and fire. This conversion was done by one of known big converters back then and are still in the business. Our conversion was one of their first ones. Who knew back then?Overheated main wiring plugs and sockets is still a problem to this day. Ask any of the rv owners. Add in corrosion, dirt, and looseness to connections. An ir gun is helpful to scan the plugs and sockets while in use quick and easy enough. And don't forget to disconnect before leaving😉

I'm still counting my blessings that I caught it before a larger problem. The cable from the generator to the panel is also 8/3, but the generator is running 30-amp breakers on each leg which makes the wire marginally acceptable. From what I can tell it's still pliable, but it's on the list of things to replace.

This whole thing has really reinforced my habit of shutting off breakers at the panel for circuits not actively in use. No sense in pushing things unnecessarily.