50amp shore power question

[s/v Jedi]

Originally Posted by Jammer

Pin and sleeve, which Jedi refers to as a "European plug" upthread. But they are big and expensive, particularly in the waterproof inlet version, which is what you need on the boat end. There are some semi-proprietary riffs on the standard that are a little more compact, too. They give up the locking ring. I don't know how good they are.

A 32A stainless steel inlet costs $120
https://shop.pkys.com/Victron-Energy...ms_p_3961.html

[fregata]

Originally Posted by GordMay

Per NEC Table 400.5: Allowable Ampacity for Flexible Cords and Cables
➥ https://up.codes/s/ampacities-for-fl...rds-and-cables

The maximum permitted ampacity for a 2 Conductor #10 AWG cord is 30 A.
A 50A cord requires #6 AWG conductors [minimum].

This was my understanding also. However, this appears to be contradicted by Ancor in the spec for their 105C cable available here (page 7): https://www.ancorproducts.com/-/medi...20200402131653

Can anyone shed some light on the discrepancy?
Or, rather is the recommendation for 6AWG cord due to 3 conductors in a 50A 2-phase shore power connection?

Is it reasonable to interpret if I had a single phase connection that occasionally exceeded 30A but did not exceed 50A (only 2 current carrying conductors, a-la multiplus boost) that 8AWG or even 10AWG is safe per Ancor spec?

[sailingharry]

Originally Posted by fregata

Can anyone shed some light on the discrepancy?

The disparity is mixing codes. ABYC is massively more lenient than NEC.
Using 105° insulation, which (I think) most of what we buy is, abyc rates number 10 wire for 60A. NEC normally limits number 10 wire to 30A (they do use an insulation temperature scale similar to ABYC, but that is not normally considered to my knowledge)
EDIT -- after doing a bit more digging, I believe that the majority of the disparity is insulation rating. Typical Ancor Marine wire is rated for 105C. Typical Romex is rated for 60C. While the temperature tables do not completely align, if you try and compare apples to apples -- or temp to temp -- the ampacities are much closer.

[Jammer]

The NEC only allows use of the 90°/105° values when both the cable and terminations are rated for the temperature in question. Few terminations -- wire nuts, plugs, receptacles, inlets, etc. -- are rated for 90° and almost none are rated for 105°. Therefore, in practice, only the 60° tables are used.


The NEC also applies a 30 amp limit to 10 AWG copper wire regardless of actual ampacity or temperature rating, just as the NEC applies a 20 amp limit to 12 AWG and a 15 amp limit to 14 AWG. Varied justifications are offered for this, among them the ease with which these relatively smaller wires can be nicked to a significant fraction of their diameter during stripping, the fact that it has always been that way and has worked, and any relaxation would compromise safety, and the fact that it better reflects the real-world thermal environment and ambient temperatures.


If you're not a licensed electrician and your work isn't being inspected then no one besides you is going to care until there's a fire.


Standard, accepted practice is to use 6 AWG copper for 50A shore power. If you deem yourself smart enough and knowledgeable enough to depart from that in your particular situation, well, that's on you.

[Jammer]

Originally Posted by s/v Jedi

A 32A stainless steel inlet costs $120
https://shop.pkys.com/Victron-Energy...ms_p_3961.html

The thing is that those aren't standard connectors and will not interconnect with standard connectors. I don't know who actually makes them (I very much doubt that they are made by Victron themselves), what kind of plastic they used, what kind of material for the contacts, etc. There's wide variation in quality.



They might be great. I don't know.

[Jammer]

Originally Posted by sailingharry

Typical Ancor Marine wire is rated for 105C. Typical Romex is rated for 60C.

All the type NM cable I've purchased recently bears a 90C temperature rating on the jacket. See for example: https://assets.southwire.com/ImConvS...20NM-B%20Cable

[tanglewood]

The Ancor and ABYC ratings above are for individual conductors bundled together. I believe the ratings are lower for cords.

[sailingharry]

Originally Posted by Jammer

The thing is that those aren't standard connectors and will not interconnect with standard connectors. I don't know who actually makes them (I very much doubt that they are made by Victron themselves), what kind of plastic they used, what kind of material for the contacts, etc. There's wide variation in quality.

They might be great. I don't know.

Jedi pointed them out in response to my comment about the renegade, non-standard, non-recognized, proprietary SmartPlug (at least, I think he did).

SmartPlug is the marine equivalent to Tesla's charging station. They are great if you have a Tesla, but sucks if you have a Leaf. Likewise, on my dock I have a standard 30A plug with a standard 30A cord. Any guest can use my cord, or run their own cord to my outlet. If my boat had a SmartPlug, then they couldn't use my cord. If my dock had a SmartPlug, then they couldn't plug in at all. If I upgraded both ends to SmartPlug, I'd have to have a "home power cord" and a "traveling power cord." (Of course, adapters can also address this issue).

And the more SmartPlug penetrates the user base (and the more "normal" it becomes), the more the monopoly will allow them to increase prices. They currently have to pay attention to the cost/benefit equation -- if they charge $500 per outlet, they won't sell regardless of how good they are. But if (when?) your marina converts to SmartPlug, you will have no choice but to pay whatever SmartPlug decides this week's profit margin is.

I wonder, though, how iron-clad their patent is? There are aftermarket competitors to the Apple Lighting plug. I can buy an aftermarket alternative to my car's front drive shaft (not a rebuild, and aftermarket). And how long does a patent last? As we seen in drugs, the day the patent expires, the price plummets.


EDIT: It seems SmartPlug came on the market in 2007. It also seems that the standard patent expires in 20 years. So we may be 4 years away from the SmartPlug being in the public domain -- and no longer a proprietary monopoly.

[s/v Jedi]

Originally Posted by Jammer

The thing is that those aren't standard connectors and will not interconnect with standard connectors. I don't know who actually makes them (I very much doubt that they are made by Victron themselves), what kind of plastic they used, what kind of material for the contacts, etc. There's wide variation in quality.

They might be great. I don't know.

You think only the US defines what is “standard”? These are the European standard. More often you find the 16A version which, at 230V, provides the same 3.6kW power as the 30A 120V in the US, but I linked the 32A because it would work for US boats.

I am told many marinas in the EU now have these 32A as well as the 16A outlets. I find the 16A outlets more and more in the US too.

[GordMay]

Originally Posted by tanglewood

The Ancor and ABYC ratings above are for individual conductors bundled together. I believe the ratings are lower for cords.

The NEC Allowable Ampacity Table 400.5, linked in my post #15, is for Flexible Cords and Cables.
NEC 400.5 ➥ https://up.codes/s/ampacities-for-fl...rds-and-cables

Allowable Ampacities of Insulated Conductors is provided in NEC table 310-16.
NEC 310.16 ➥ https://www.nfpa.org/~/media/Files/C...tyWorkflow.pdf


As Jammer noted, ABYC is MUCH LESS stringent, in their ampacity ratings, than the NEC.

[GordMay]

Typical North American Shore Power Cords are made using PVC Jacket* type “STOW” or “STO” rated 600V, 60° C [140° F].

* Portable Cord Types
S = Stranded (or Service Wire)
T = Thermoplastic. If no "T" is in the wire type, then it has a rubber jacket.
O = Oil-Resistant Compound
W = Weather-Resistant Compound
ST = Extra hard service cord for general use at 600 volts, rated at 4°F [-15.56°C] to +140° F [60° C], PVC thermoplastic insulated and jacketed.
STO = Type ST, but also rated oil resistant.
STOW = Type STO, but rated for outdoor use at -31° F [-35°C].

[Jammer]

Originally Posted by s/v Jedi

You think only the US defines what is “standard”? These are the European standard. More often you find the 16A version which, at 230V, provides the same 3.6kW power as the 30A 120V in the US, but I linked the 32A because it would work for US boats.

The pin and sleeve standard, if I recall correctly, is defined by the International Electrotechnical Commission, and not by either the USA or Europe. A quick search pulls up IEC 60309 as the standards document. As you describe, IEC 60309 connectors in single phase, grounded, 220 volt, 16a, is widely used in Europe for shore power.



The Victron connector isn't made to IEC 60309. It's similar, but it doesn't have the locking ring.

[s/v Jedi]

Originally Posted by Jammer

The pin and sleeve standard, if I recall correctly, is defined by the International Electrotechnical Commission, and not by either the USA or Europe. A quick search pulls up IEC 60309 as the standards document. As you describe, IEC 60309 connectors in single phase, grounded, 220 volt, 16a, is widely used in Europe for shore power.

The Victron connector isn't made to IEC 60309. It's similar, but it doesn't have the locking ring.

The European connectors, used in every marina not just in Europe but I think the world over incl. USA, do not have a locking ring. The lid of the outlet/inlet hooks behind the connector, locking it. Smartplug copied that.

Here you see West Marine selling a cord for Us boats: https://www.westmarine.com/marinco-5...RoCllEQAvD_BwE

And attached the wikipedia page. The shore power connectors used are the blue 2+E versions in both 16A and 32A.

The Victron connectors are the standard.

[Stu Jackson]

Harry,


Your discussion appears quite off the mark. Why? Because everyone I know who has installed a Smart Plug has ONLY DONE IT AT THEIR OWN BOAT END.


I haven't heard of any marina even thinking about doing it at their end.

Originally Posted by sailingharry

Jedi pointed them out in response to my comment about the renegade, non-standard, non-recognized, proprietary SmartPlug (at least, I think he did).

SmartPlug is the marine equivalent to Tesla's charging station. They are great if you have a Tesla, but sucks if you have a Leaf. Likewise, on my dock I have a standard 30A plug with a standard 30A cord. Any guest can use my cord, or run their own cord to my outlet. If my boat had a SmartPlug, then they couldn't use my cord. If my dock had a SmartPlug, then they couldn't plug in at all. If I upgraded both ends to SmartPlug, I'd have to have a "home power cord" and a "traveling power cord." (Of course, adapters can also address this issue).

And the more SmartPlug penetrates the user base (and the more "normal" it becomes), the more the monopoly will allow them to increase prices. They currently have to pay attention to the cost/benefit equation -- if they charge $500 per outlet, they won't sell regardless of how good they are. But if (when?) your marina converts to SmartPlug, you will have no choice but to pay whatever SmartPlug decides this week's profit margin is.

I wonder, though, how iron-clad their patent is? There are aftermarket competitors to the Apple Lighting plug. I can buy an aftermarket alternative to my car's front drive shaft (not a rebuild, and aftermarket). And how long does a patent last? As we seen in drugs, the day the patent expires, the price plummets.


EDIT: It seems SmartPlug came on the market in 2007. It also seems that the standard patent expires in 20 years. So we may be 4 years away from the SmartPlug being in the public domain -- and no longer a proprietary monopoly.

[sailingharry]

Originally Posted by Stu Jackson

Harry,


Your discussion appears quite off the mark. Why? Because everyone I know who has installed a Smart Plug has ONLY DONE IT AT THEIR OWN BOAT END.


I haven't heard of any marina even thinking about doing it at their end.

I have never seen one at a dock either. But I know they sell them for the dock end and the vast majority of arguments in favor of putting it on the boat apply equally to the dock.
I didn't press for details, but at the Annapolis boat show the smartplug people were telling me something about marinas installing them. For those that use marinas or plug in when they do use one, that is a troubling concern.

While it is more of an aberration than a real issue, I have a guest slip at my dock and my boat is normally plugged in. But when a guest visits, I unplugged the cord from my boat and plug it into theirs. Because the plugs are an established standard, it is super convenient. Admittedly, this is not a major justification for using or not using a smartplug.