Visit our Popular Forums

CharlieJ · 30-12-2009, 08:36

There is an improvement for the standard Marinco/Hubbell receptacle that eliminates the inherently poor contact of these plugs and receptacles and includes a temperature sensor that opens the circuit if the boat side connection gets too hot: SmartPlug 30 Amp Marine Inlet and Connector

jkleins · 30-12-2009, 09:25

Quote:

Originally Posted by sailvayu

The female ends of 30 AMP cords are often where problems start

Attachment 12246

This is a classic example of what I see all the time

good Luck

So what causes this?

Jim

sailvayu · 30-12-2009, 09:25

At $225 for just the boat ends no cord it better be smart lol These cords do need better plugs but at that cost I do not see a lot of folks jumping on that boat lol

Fair Winds

Cheechako · 30-12-2009, 09:34

As the picture shows, the boat end often slowly burns up. I would guess from poor contact/ higher resistance. I think the permanent wiring scheme is a good idea... especially for anyone drawing many amps like an electric heater. When living aboard I would go through a 30 amp cord set every year with an electric heater.

sailvayu · 30-12-2009, 09:41

Jim
Heat is caused by resistance. The most common reason for this a high load on the shore cord combined with mild corrosion and a poor contact of the connection. Most boats I see with this problem have AC units. The problem is the connection just gets worse and the more heat the more resistance till it melts down.

Click image for larger version

Name: IMG_1567.jpg
Views: 167
Size: 429.8 KB
ID: 12260

This is a picture of an inlet that was on a boat where the owner installed a AC unit but failed to upgrade the wire from the inlet to the panel. It was a #12 wire as that was all the was needed when the boat was built in the 80s with little AC load. If you look you can see the wire to the right note the insulation burned off the black wire. This was very close to catching on fire, fortunately the cord failed before a fire could start.

I try to recommend adding an additional 30 amp service just for AC units but am often met with the argument it does not exceed 30 AMPs. True but it gets close and you can see what the results can be when working on the edge. It does cost more but can save your boat from a fire.

At the very least keep a close eye on the condition of your shore cord both ends and fix what is wrong right away. If you keep having to replace cord ends something is wrong and you need to have it checked. You are likely using more amps than your cord can safely handle.

Fair Winds

**James S** · 30-12-2009, 09:59

Quote:

Originally Posted by CharlieJ

There is an improvement for the standard Marinco/Hubbell receptacle that eliminates the inherently poor contact of these plugs and receptacles and includes a temperature sensor that opens the circuit if the boat side connection gets too hot: SmartPlug 30 Amp Marine Inlet and Connector

Even at that price its damned cheap insurance.
Cool!

CharlieJ · 30-12-2009, 10:49

jkleins-
The boat receptacle (male) has holes punched into each blade. The cord set boat end has female mating sockets with dimples that engage the holes in the male end with slight spring force. As the spring force is reduced through age, the dimples and holes are not engaged. If the cordset is not completely "locked" (dimple/hole engaged), then the dimple is making the electrical contact and it is essentially a point contact without enough surface area for the rated capacity of the cord set.

This is the result:

Click image for larger version

Name: Burnt <a title=

shore power inlet and plug.JPG Views: 125 Size: 284.9 KB ID: 12264" style="margin: 2px" />

jkleins · 30-12-2009, 11:48

Thanks for that info. I noticed this on the original cord that came with the boat and was wondering. Time to replace the connector, I suspect. It is hard to screw on the collar anyway.

I am going to look closely at the SmartPlug.

Jim