Smartplug inlet design weakness

[Muaddib1116]

I just invested in a bunch of smartplug equipment, and I think it's pretty much immediately apparent how the design is better than the standard twist lock equipment, even marinco's EEL system.

That being said, there seems to be one area where marinco has smartplug beat, and that is on the back of their boatside inlets. My marinco 50a 125/250 inlet had a strain relief clamp and a splash resistant cover that protects the area where the wiring is clamped into the inlet. Smartplug's 50a 125/250 inlet has neither of those things. For most installations that's probably fine, but my inlet is wired into my aft lazarette, which will potentially have some wet equipment in there.

I'm going to experiment with some heat shrink to at least try to provide some moisture protection. I don't have any ideas right now about adding some strain relief.

I don't think it would be hard for them to add both of these things. They could borrow some of it from their existing plug replacement kit systems.

On the whole, it's a clearly superior product design though.

[GreenWave]

This post is very timely as I just ordered one conversion kit. I have three inputs total. and mine also enter in the aft laz.

[Muaddib1116]

I have one of the 50A conversion kits to put on my marinco reverse Y adapter. The nice thing is that it came with two different sizes of the black water resistant boots for different sized cables. Since the reverse Y is only running at 30A, it is 10gauge wire, and I was worried that there wouldn't be a good water resistant fit. I think with the smaller boot, it will work. If I ever go to a country with European dock power, I'll make an adapter with a Euro shore power cable and another smartplug conversion plug kit.

I'm still brainstorming ideas to protect the back of the inlet. If I come up with something that works, I'll post pictures. I'm not sure there's much I can do about adding strain relief. Maybe I can take the clamp from my marinco inlet and attach it somehow to the back of the smartplug inlet, with epoxy putty or something.

Are yours 30A inlets? three inputs seems unusual.

[s/v Jedi]

Here’s what you do:

1. Use crimped ferrules on the conductors. This keeps all strand in line and protects them.

2. Push some dielectric grease into the terminal before sticking the conductor in. Coat the crimped ferrule with dielectric grease elaborately as well.

3. Find or create an attachment point for the cabling behind the inlet. It should be within 10 inches of the inlet. While tightening the attachment, push an extra inch or two of cable towards the inlet, creating a slack there to relieve strain.

[Muaddib1116]

Originally Posted by s/v Jedi

Here’s what you do:

1. Use crimped ferrules on the conductors. This keeps all strand in line and protects them.

2. Push some dielectric grease into the terminal before sticking the conductor in. Coat the crimped ferrule with dielectric grease elaborately as well.

3. Find or create an attachment point for the cabling behind the inlet. It should be within 10 inches of the inlet. While tightening the attachment, push an extra inch or two of cable towards the inlet, creating a slack there to relieve strain.

Great stuff, thanks Jedi! When you said to coat the crimped ferrule as well, do you mean before you crimp it, grease between the ferrule and wires and then crimp? or on the outside after crimping?

[s/v Jedi]

Originally Posted by Muaddib1116

Great stuff, thanks Jedi! When you said to coat the crimped ferrule as well, do you mean before you crimp it, grease between the ferrule and wires and then crimp? or on the outside after crimping?

If you think of it in time, you can do it before crimping. The grease will not interfere with electrical contact but will protect everything coated by it. I crimp without it because it gets messy otherwise.

You can squirt this into all clean connectors incl, Ethernet RJ-45. After the connection is made, use something to wipe excess away and it’s good.

[Jammer]

Originally Posted by Muaddib1116

On the whole, it's a clearly superior product design though.

A new connector is better than a 20 year old connector; all connector designs fail over the course of years with mechanical wear from connection and disconnection, exposure to a wet salty environment, being out in the sun, and thermal cycling.


What is unclear to me is whether the "obvious," "clear" design benefits i.e. larger contact area and separation of the locking mechanism from the contact mechanism, will translate into longer useful life.


Least of all is it clear to me whether the people at SmartPlug will be able to sustain consistent quality and availability of product over a span of decades, as Marinco, Legrand, and other established electrical manufacturers have done with the twist locks.

[s/v Jedi]

Originally Posted by Jammer

A new connector is better than a 20 year old connector; all connector designs fail over the course of years with mechanical wear from connection and disconnection, exposure to a wet salty environment, being out in the sun, and thermal cycling.


What is unclear to me is whether the "obvious," "clear" design benefits i.e. larger contact area and separation of the locking mechanism from the contact mechanism, will translate into longer useful life.


Least of all is it clear to me whether the people at SmartPlug will be able to sustain consistent quality and availability of product over a span of decades, as Marinco, Legrand, and other established electrical manufacturers have done with the twist locks.

There’s no question that their product outperforms the 120V/30A type connectors. It’s not a question of aging but of inferior design. Compare to EU 230V 16A connector, I never burned one of those while the US counterparts by the loads.

I must say I never had trouble with the 120/240 50A connectors, those are way better.

[Muaddib1116]

Originally Posted by Jammer

A new connector is better than a 20 year old connector; all connector designs fail over the course of years with mechanical wear from connection and disconnection, exposure to a wet salty environment, being out in the sun, and thermal cycling.


What is unclear to me is whether the "obvious," "clear" design benefits i.e. larger contact area and separation of the locking mechanism from the contact mechanism, will translate into longer useful life.


Least of all is it clear to me whether the people at SmartPlug will be able to sustain consistent quality and availability of product over a span of decades, as Marinco, Legrand, and other established electrical manufacturers have done with the twist locks.

Fair points. I think my statement that the design is superior stands. The quality seems pretty good, at least as good as the Marinco products I have. I can't account for how they'll age, I'm just commenting on build/construction quality that I can observe when new.

At this point, I don't know how they'll age compared to how the twist-lock designs age, but I think I can make some educated guesses based on the features of the design and how it functions as new. I suspect the male contact pins and corresponding female contacts will maintain superior connection over time compared to the twist lock design. This is based on the contact surface area as new, as well as their shape and how the contact is made, with flat large SA contact leaf springs.

The locking levers on the sides of the plugs can be replaced if they wear out. The sealing o-rings can be replaced. Eventually, you can even replace the connector plug and inlets if the cable is in good shape (as you can with Marinco). Overall, I suspect that they will age well and continue to perform, and have at least as much replaceability/fixability as the twist lock design.

As far as how well the company will be able to maintain their quality and availability as the company grows and their manufacturing develops, that's impossible to say. But I believe they've been around for around 15 years.

[GreenWave]

Originally Posted by Muaddib1116

I have one of the 50A conversion kits to put on my marinco reverse Y adapter. The nice thing is that it came with two different sizes of the black water resistant boots for different sized cables. Since the reverse Y is only running at 30A, it is 10gauge wire, and I was worried that there wouldn't be a good water resistant fit. I think with the smaller boot, it will work. If I ever go to a country with European dock power, I'll make an adapter with a Euro shore power cable and another smartplug conversion plug kit.

I'm still brainstorming ideas to protect the back of the inlet. If I come up with something that works, I'll post pictures. I'm not sure there's much I can do about adding strain relief. Maybe I can take the clamp from my marinco inlet and attach it somehow to the back of the smartplug inlet, with epoxy putty or something.

Are yours 30A inlets? three inputs seems unusual.

I am going to reach out to a fellow sailor who put the Smartplugs in his old boat which is same as mine. My inlets are 30amp each. I have 50 amp service on dock and use splitters to get what I need. I am rarely over 20 amp draw on any AC input. Most Catalina 470s just have two 30 amp service inlets.

[Sailshabby]

Originally Posted by Muaddib1116

I just invested in a bunch of smartplug equipment, and I think it's pretty much immediately apparent how the design is better than the standard twist lock equipment, even marinco's EEL system.

That being said, there seems to be one area where marinco has smartplug beat, and that is on the back of their boatside inlets. My marinco 50a 125/250 inlet had a strain relief clamp and a splash resistant cover that protects the area where the wiring is clamped into the inlet. Smartplug's 50a 125/250 inlet has neither of those things. For most installations that's probably fine, but my inlet is wired into my aft lazarette, which will potentially have some wet equipment in there.

I'm going to experiment with some heat shrink to at least try to provide some moisture protection. I don't have any ideas right now about adding some strain relief.

I don't think it would be hard for them to add both of these things. They could borrow some of it from their existing plug replacement kit systems.

On the whole, it's a clearly superior product design though.

Unless an unthinking crew member steps on it, at which point the wire holders inside snap off and rip the wires free. Don’t ask me how I know...

[Grattaway]

Nice to see an improvement in design but I am not really convinced that the world needs another plug format given what is already available. We handle a lot of refrigerated shipping containers with a "universal" plug design that is pretty robust and handles all sorts of misuse and marine environments - its just a pain that global wasnt seen as important when countries designed their own systems

[Leee]

The weakest area on the 30 A units is the hinged cover. Replacing my failed plastic one with a metal one (which looks and feels more robust) which will hopefully last longer. Other than this issue, which involves replacing the entire unit, it's fine.

[s/v Jedi]

Originally Posted by Leee

The weakest area on the 30 A units is the hinged cover. Replacing my failed plastic one with a metal one (which looks and feels more robust) which will hopefully last longer. Other than this issue, which involves replacing the entire unit, it's fine.

The metal units are built like a tank. Also, spotless after years in use on salt water and rough weather.

[donradcliffe]

I'll never again replace a 30 amp Marinco with the same design. Even the RV 30 amp plug is better. One of the Smart Plugs I put is going strong on year 8 of a liveaboard that burned up a Marinco every other year.