More Shore Power Discussion

[CaspersCruiser]

In another thread, I detailed changing the shore power inlet on my 2012 R27 from the standard twist-lock to a Smart Plug. My boat was previously owned by a couple of serious cruisers who used the boat a lot. It’s most likely one of the highest time R27s on the water. The generator probably has more hours- 335- than most R27s have on their engines!

That high time means the shore power inlet saw lots of use and shore power cord on-off cycles. During the Smart Plug inlet installation, when I inspected the shore power wiring after removing it from the existing inlet, it looked brand new. There were no signs of thermal stress that often occurs in shore power inlet installations.

I have many years experience owning and flying small airplanes and the parallels between airplanes and boats are many. One is how they’re used: They tend to sit idle for long periods between use. And not surprisingly, that creates corrosion problems for both.

This is just an informed hunch, but I suspect why the shore power wiring on my boat was in such good shape is that the regular on-off cycle of the shore power plug kept the shore power cord and inlet contacts clean and corrosion-free. The corrosion-free contacts prevented the heat that comes with high resistance.

It’s well established that twist-lock contacts of shore power cords and inlets can be inadequate and incomplete and this may lead to corrosion, despite being connected. So, even if your boats sits in a slip with shore power connected, it may be a good idea to regularly brighten up the shore power contacts on your vessel to prevent the corrosion that produces high resistance and heat.

 

[HRowland]

I use electrical contact grease, a thin coat on the shore power prongs and boat side blades. I also have the dust cover for the boat end of the Smart Plug shore power cord.

I use NO-OX-ID for this and all electrical connections, battery terminals, etc. Great stuff.

http://www.sanchem.com/electrical-conta ... icant.html

Howard

 

[bill46]

Agree with both above. Conductive grease and remove and replace monthly. Prior owner let sit and main inlet burned up. I see no need foe “smart plugs”. Most problems I see are marinas. I use one 30, but have 50 to 2-30for marinas with bad receptacles. NEMA twistlocks have been used for many years without problems.

 

[ixlr8]

Agree with both above. Conductive grease and remove and replace monthly. Prior owner let sit and main inlet burned up. I see no need foe “smart plugs”. Most problems I see are marinas. I use one 30, but have 50 to 2-30for marinas with bad receptacles. NEMA twistlocks have been used for many years without problems.

We had equipment were I worked that that pulled 20+ amps, they were plugged in with NEMA twist-lock connectors. Ran 24/7 for over 20 years, only unplugged once per year for maintenance on the equipment, never had any issues. From reading between the lines in all the posts I have seen there are basically two issues. The 'socket' on the boat didn't have the wires tightened down properly at the factory, and the connector not being used enough to keep the contacts clean. Twist-locks can be a pain to line up and that is almost enough reason to change to the "smart plug". But there is no reason a properly maintained twist-lock connector won't last the life of the boat. You can bet the first maintenance item I am going to tackle when I get my new boat is to check the shore power socket wiring to make sure the wire clamps are tightened properly.