Access to AC power from shore to AC panel.

[Svseptember]

I have a 2005 Hunter 44 AC. After my last haul out, I found one of the 30 amp cables laying on the dock with one of the prongs melted off.

After replacing the cable and some troubleshooting, it appears I have no power somewhere between the incoming shore power 2, the isolation transfer, and the AC panel. I’m still able to bridge the panels and power everything from one 30AMP cable.

My question is how do I get access to the areas from shore power 2 -> isolation transfers -> AC panel. I don’t see any easy access panels.

Thanks,
Karl

 

[Tin Kicker]

I don't have a Hunter but if there was enough heat to melt the copper then I'd start with disassembling the plug itself. Do this before anything because copper melts at a high enough temp to gut the plastic material holding the contacts apart. Shorts like these can lead to fire. Further, because the copper and steel terminals are different metals, that much heat can lead to loosening of the metal connections.

I recently replaced the shore plug with a SmartPlug because the spring for the cover door was broken. The SmartPlug is very impressive and I should have considered replacing the original regardless.

The original plug was dirty but not browned (front or back) and gave no visible clues of a potential problem. However, once the strain relief bar was removed from the back of the plug two of the three wires slipped right out and the copper had evidence of discoloring locally plus minor points of melting. One big benefit of the SmartPlug is that it will disconnect if it senses heat from this type of resistance, rather than letting a plug like mine build resistance till it begins to arc or burn.

So something to consider at least adding to the Spring maintenance list is a check for the tightness of the screws which hold the wiring into old round plugs. Takes about 20 minutes and costs nothing.

Two more observations:

One is the blackness of the copper contacts shown. Periodic maintenance ought to include cleaning the copper prongs with Scotchbrite (not steel wool!)

Second, the prongs also had a number of arc marks. Somebody had not been plugging the cord into the boat THEN the cord into the shore box.
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[Ron20324]

As I said in a thread a couple weeks ago, Shut both breakers off, then plug in cable, boat end first, then turn breakers on.

 

[Svseptember]

Thanks Tin. The burned prong was on the shore end but I'll take a closer look when I get to the boat this weekend.

 

[Svseptember]

Thanks Ron, this is indeed my standard procedure. However, in this case, the marina took the boat from my slip, did the haul out, and moved it back while I was out of town. So, given that the damage has already been done, do you have any advice on how to access the path from shore power to AC panel?

 

[Ron20324]

... any advice on how to access the path from shore power to AC panel?

I assume your boat has 30-amp ckt brkers within 10 feet of the connector? Probably tucked in the lazz?

 

[Svseptember]

I assume your boat has 30-amp ckt brkers within 10 feet of the connector? Probably tucked in the lazz?

Hi Ron, more like 2' in the aft state room. I've flipped the breaker back and forth with no joy. The entire ceiling of the aft is hardshell. I guess I can try to remove the breaker (about the size of my hand) and try fishing around in there but they sure don't provide a lot of room or access.

 

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[Tin Kicker]

Disconnect the breaker and put a multimeter across it. C/Bs can have up to a 20% failure rate.

 

[Svseptember]

Thanks Tin,

I didn’t realize they were that unreliable. I’ll check it this weekend.

Regards,
Karl

 

[DayDreamer41]

You indicated that the main 120 V breakers are mounted on the aft bulkhead as is ours on the 41DS, and I believe are accessible from the rear lazarette, its not so bad getting in, and once in, its rather roomy, the fun begins getting out especially when the girth is about the same as the opening size.

 

[Svseptember]

You indicated that the main 120 V breakers are mounted on the aft bulkhead as is ours on the 41DS, and I believe are accessible from the rear lazarette, its not so bad getting in, and once in, its rather roomy, the fun begins getting out especially when the girth is about the same as the opening size.

Thanks DayDreamer. However, my breakers are mounted on the hardshell ceiling instead of the bulkhead. I’ll take a photo this weekend if I can’t fix once I remove the breaker panel.

Either way, I’ll let you know the results.

 

[Svseptember]

It was indeed the breaker - all good now. Thanks for the help

 

[Project_Mayhem]

Shorts like these can lead to fire.

This man speaks the truth! I installed a 30 amp circuit in a garage. It was late and I tripped and caught myself on the wall mounted conduit before the install was complete. One of the hangers came loose and I ended up pulling the conduit down. The 10awg solid wires got pulled and shorted resulting in one of the boxes catching on fire (yes, the bare metal!). I was left shielding my face while blowing out the flames and praying that the breaker would trip. Finally after about 15 seconds it did. Fun times

 

[Tin Kicker]

SVSept - Congrats on resolving it.

Mayhem - My forum name is the knick name for accident investigators. Oh - The fires I've seen.
Seriously, glad you were OK. Love your insurance commercials btw.