EU power cables in US

[madmattius]

Is it possible/wise/safe to 'chop' the blue EU shore power plugs off and fit the standard US 50 amp plugs?

Thanks

[steve77]

It is possible, but not advisable without confirming the size of the conductors of your shore power cable.

Shore power cables in the US are typically larger than those in Europe because of the lower voltage. A 50 Amp plug should have conductors sized as #8 awg. This is assuming the terminals are rated at 75 degrees C, which I believe they are.

If your conductors are smaller than a #8, you should not connect a 50 Amp plug to them.

Cheers!

Steve

[madmattius]

Thanks for the reply, just checked my current cables and they are max 32a, so I guess I'm gonna need to buy some thicker cable and recycle the male fittings to the boat

[hellosailor]

If you have the good sense (honestly) to ask about this stuff, but lack the electrical know-how....Really, the EU cords specify anoxic metric copper alloys for the wiring, and US cables use plain AWG "imperial" wiring, so no, the two should never be mixed.


Between a good chandlery and a good professional electrical supply house (more reliable than the big box stores when it comes to details) you should be able to bring your pieces in, do a show-and-tell, and get really solid answers in the same place that will sell you the parts you need.

[smac999]

Also the U.S. 240v 50a plugs are 4 wire. Your 230v cable is 3

Are you trying to plug a 230v 50hz boat into 240v 60hz? You need more then just a different end.

[valhalla360]

Originally Posted by hellosailor

If you have the good sense (honestly) to ask about this stuff, but lack the electrical know-how....Really, the EU cords specify anoxic metric copper alloys for the wiring, and US cables use plain AWG "imperial" wiring, so no, the two should never be mixed.


Between a good chandlery and a good professional electrical supply house (more reliable than the big box stores when it comes to details) you should be able to bring your pieces in, do a show-and-tell, and get really solid answers in the same place that will sell you the parts you need.

Wouldn't want english unit electrons running thru metric copper. At best there may be a tiny difference but really not the issue.

The real issue is how voltage and amperage play together. To move the same number of watts at half the voltage, you need double the amperage. The number of amps that a wire can handle is a function of material, length and cross sectional. Also, US 50amp is a 4 wire plug (2 120v legs, a neutral and a ground). That's different from EU 3 wire plug that has a single 240v leg.

Then there is the 60hz vs 50hz issue which adds another layer of complication depending on what you are trying to run.

So no, you can't just lop the end off and plug an EU cord into a US outlet. Go take a look at the size of those 50amp cords on US docks. They are massive by comparison and there is a reason.

[steve77]

There is a way to do what you want to do, but I would not be comfortable giving instructions without knowing your electrical system. I would recommend you get a licensed marine electrician.

You don't want a 50 Amp breaker protecting your boat. If you have a 16 Amp incoming breaker for the boat, then a 50 Amp breaker upstream protecting a shore power cord with a 50 Amp plug and #8 conductors is ok.
The 50 Amp breaker protects the cord and the 16 Amp breaker protects the boat.

First, go around the boat looking at your 230 Volt loads and see if they are rated for 50/60 Hz. When you have that data, go talk to an electrician about the power connection and the 60 Hz issue.

Cheers!

Steve

[GordMay]

Greetings and welcome aboard the CF, madmattius.

[exMaggieDrum]

The other issue is the size internal AC wiring that comes with most boats built for 220v, as in Europe. They use smaller wires, not just for the shorepower, but for the panel, and circuit wiring, and probably to the battery charger which may be able to handle 110v/60Hz but the wiring to it cannot. You can only put half the amps through those wires using 110v. Be very, very careful and understand what you intend to do and what you need to do.

[leftbrainstuff]

Originally Posted by madmattius

Is it possible/wise/safe to 'chop' the blue EU shore power plugs off and fit the standard US 50 amp plugs?

Thanks

Not if you're switching to a lower voltage. Although you mention 50 Amp so assume you want to use 250V US.

This is electrics 101. Suggest you seek specialist advice on the safest, not cheapest option, to access shore power.

What will be the impact on your consumers? Autoswitching for voltage, phase mismatch, power factor, wire condition, etc.

You'll likely find its about the same price to just buy new cords. If you cut and shut them by the time you seal the ends, buy the connectors and do the swap the price difference is not great.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[DotDun]

Originally Posted by exMaggieDrum

The other issue is the size internal AC wiring that comes with most boats built for 220v, as in Europe. They use smaller wires, not just for the shorepower, but for the panel, and circuit wiring, and probably to the battery charger which may be able to handle 110v/60Hz but the wiring to it cannot. You can only put half the amps through those wires using 110v. Be very, very careful and understand what you intend to do and what you need to do.

This is not true.

What is true is you get less power, measured in watts or volt-amps, delivered to the appliance. The amps are the same. EU-230v wiring rated at 16 amps (2.5mm2) can carry 16 amps of US-120v. The EU circuit breaker will still protect the wire properly.

Reality:
230*16 = 3680 watts/va
120*16 = 1920 watts/va

[hellosailor]

Since the makers spec their wire for anticipated load, regardless of voltage, and the the AC wiring that is usually chosen for the maximum ampacity the wires will need, the EU wiring will indeed carry the same wattage on 110 or 220, but the ampacity will be half that of what they would have used for 110 circuits.


So you're EU hairdryer at 1600 watts may pull 8 amps and be given a circuit rated for 8 amps to plug into. But when you change that circuit to a 110 source and a 110 hairdryer, ooops. The wire can still carry 8 amps but the hairdryer pulls 16.


This is actually a specific problem in many US homes, where each circuit is/was traditionally fused at 15 amps for 110/120 service (117 is our actual nominal voltage, +-10%, under federal rules) but the common hand-held hair dryers are almost all rated at 1600 watts, so the lights dim and fuses blow in homes with older wiring. Everyone wanted "more power" and the hair dryer makers gave it to them. Fontunately a few cheated on how close to 1600 they came.

[DotDun]

Originally Posted by hellosailor

Since the makers spec their wire for anticipated load, regardless of voltage, and the the AC wiring that is usually chosen for the maximum ampacity the wires will need, the EU wiring will indeed carry the same wattage on 110 or 220, but the ampacity will be half that of what they would have used for 110 circuits.


So you're EU hairdryer at 1600 watts may pull 8 amps and be given a circuit rated for 8 amps to plug into. But when you change that circuit to a 110 source and a 110 hairdryer, ooops. The wire can still carry 8 amps but the hairdryer pulls 16.


This is actually a specific problem in many US homes, where each circuit is/was traditionally fused at 15 amps for 110/120 service (117 is our actual nominal voltage, +-10%, under federal rules) but the common hand-held hair dryers are almost all rated at 1600 watts, so the lights dim and fuses blow in homes with older wiring. Everyone wanted "more power" and the hair dryer makers gave it to them. Fontunately a few cheated on how close to 1600 they came.

Have you found EU AC wiring/circuits on boats rated at 8 amps?

[hellosailor]

Is that a facetious question, or do you think I've got nothing better to do than disassemble EU boats and apply calipers to their wiring?

[Stu Jackson]

Originally Posted by hellosailor

This is actually a specific problem in many US homes, where each circuit is/was traditionally fused at 15 amps for 110/120 service (117 is our actual nominal voltage, +-10%, under federal rules) but the common hand-held hair dryers are almost all rated at 1600 watts, so the lights dim and fuses blow in homes with older wiring. Everyone wanted "more power" and the hair dryer makers gave it to them. Fortunately a few cheated on how close to 1600 they came.

Very true. In our rental home, we learned pretty soon after we moved in that the hair dryer in the master bathroom would trip a breaker if the air conditioning was running.

I just told my wife to go outside since if it was hot enough for the air conditioning to be running...

Then I started running.