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updating wiring

Posted: Sun Apr 08, 2018 7:14 pm
by rlambert
Looking for input. I am looking at updating some electrical on our new to us 73 28 Express. The shore inlet is a 20a plug, I am wanting to change to 30amp standard shore power inlet. The wiring from the inlet go to a box with two breakers, one 20a and one 30a. I hope to later upgrade to an actual AC panel. but I am wondering if just changing the inlet to 30a will work ok with the current setup.

Re: updating wiring

Posted: Mon Apr 09, 2018 10:00 am
by rlambert
Does anyone have any input or thoughts as to why you couldnt change the inlet form 20amp to 30 amp? I have never even seen a 20amp inlet till we got this boat and I could not match the cord!

Re: updating wiring

Posted: Tue Apr 10, 2018 6:38 am
by tjc7t7
If you decide to upgrade to the 30 amp inlet the only potential issue I see is the wire that feeds the circuit breaker box. I can not tell from the pictures what size it is. The wire needs to be a 10 AWG. This should be stamped on the wire itself along the outer insulation.If there using a 20 amp inlet right now they would only need a #12 wire. You always want to make sure your wire is sized correctly for the fuse or breaker that your using otherwise the wire not the breaker becomes the weak link in the circuit and thats how fires start.

Re: updating wiring

Posted: Thu Apr 12, 2018 4:02 am
by MetalHead
Is that Romex (household) wire? You should consider replacing it with a marine equivalent.

https://www.westmarine.com/buy/ancor--t ... ecordNum=2
https://www.westmarine.com/buy/blue-sea ... cordNum=13

Re: updating wiring

Posted: Thu Apr 12, 2018 8:02 am
by brokebill
Big no, no to use solid conductor wire on a boat. It has to be marine wire, which means that it is silver coated, annealed, stranded wire. It's not cheep but is good insurance against fires and faulty wiring. Everything on boats moves independent of everything else. The solid wire will eventually form stress cracks and break off near the point of termination. That is why marine service rated wire has around thirty strands per conductor and the strands are individually silver or tin coated to prevent corrosion. There is some free information from the American Boat and Yacht Council. If you ever sell and need a survey the surveyor will require that the wiring be brought up to council code.

Re: updating wiring

Posted: Sun Apr 15, 2018 7:24 pm
by railrunner04
I second that on the romex when we redid the 32 it was a horror show romex wire bent around hard edges it's a miracle no one got blasted out of their shoes climbing on the boat because there was no ground connected to the hull at all!

I know it's a pain but your way better off removing all that and starting fresh good luck with it

Re: updating wiring

Posted: Sun Apr 15, 2018 8:39 pm
by rlambert
Yep I plan on re doing the AC before using any of it. I cannot find a ground buss bar for Ac or DC..... am i missing something ????? is it hidden somewhere?

Re: updating wiring

Posted: Mon Apr 16, 2018 6:45 am
by railrunner04
The a.c. ground if there is one with the romex mess would go right back to shore based on what we found repairing the a.c. on my dad's boat you don't want that as previously discussed.
If its any different I'd look for a galvanic isolator I doubt you have one based on the condition of the shore power but you never know. When you redo the a.c. definitely look into installing one

The dc power ground bus may be up in behind the helm I'm not sure if it was factory or someone did this on the 32 but there was a whole mess of white wire attached to lugs on an aluminum plate that was grounded to the ground lug with some skimpy wire on the hull

As you may know or come to find out the wiring on these early 70's M's are mostly a disaster just have to weed through it take lots of pictures.