220V European vs 110V United States

You are going for rather high power: Why not a simple 3f connection for the steam generator, with a remark on how to wire it up for single faze systems.

Chose the minimal connection to be 20A. 15A with a 13.5A load will result in nuisance.

And impose a 30mA RCD on the system. As the manufacturer you simply can impose it and the users have to use it, no local regulation can alter your own rule.

Don't take the risk of electrocution of a customer.

Gwen

I'm assuming this is in his home and it would be extremely rare for there to be 3 phase power in a US home. US homes would have "split-phase", 2 110V phases 180 degrees out which can be used phase to phase for 220 or phase to neutral for 110.

Shawn

Is it for his home or does he wants to sell his actual product in another market?

When he bought a CE product and want's to use it in his bathroom, I would pay serious attention on how to connect it. Ans ask an inspection before use: if somethings happens in 20 years and someone is dead of injured the insurance might pull out as he used a non US certified apparatus. Especially in a wet room I would be very cautious with these things. (I would not do it)

A CE labeled product is having a different approach on safety than you are used to handle in the US, mixing the two might invoke dangerous situations. (We tend to use citcuit RCD's where US products for wet usage usually have their own RCD, ...)

I know of this strange way of connecting in the US. Weird people over there.

Gwen

What is an RCD?

An RCD is Residual Current Device which does the same thing as what we call a GFCI in the US. It disconnects the circuit if there is an imbalance between the hot and neutral, meaning current is flowing back through ground via a means other then the Neutral wire.

Shawn

RCDs or GFCIs are protective devices & their function is to open (disconnect from voltage source) the circuit when its isolation (circuits) is faulty i.e. some voltage can be present outside the circuits (e.g. on a hair dryer) because it is dangerous for the user in wet location (e.g. bathroom).

By the way, there are also 3-phase GFCI for motors etc.

These devices act ("interrupt") the protected circuit in milliseconds when difference in current is several mA even their nominal/rated current is e.g. 20 A. It is no fun when human body becomes another path for current to ground. The value of 8 mA shocks!

More (to Amps) kills

Is it a true that those values were found by experimenting on koncentration kamp's prisoners?

Interpretations of US 240-120 V, mostly residential systems are both correct.

Houses have "services" from the secondary windings of transformers with the center tap, and it is usually grounded and called neutral. Zero or 180 degree between 120 V circuits depends of "point of view". Connecting two-channel o-scope to two both "hot" wires with neutral as a common will show voltages' 180 degrees!

Your description of a residential consumers service is misleading. The system referred to as being "split phase" actually consists of one 240 volt single phase source with a center tap pulled out from it.

When we pull the center tap out from the 240 volt winding on the supply transformer we now have to 120 volts sources connected in series, the polarity of the individual sources are additive. That is why they sum to 240 volts, not because of any phase difference between them as there is no phase difference between the two sources.

The only time it looks like there is a phase difference is when the ends of the 120 volt windings are referenced from the center point tap.

The center tap, while referred to as a "neutral", is not actually a neutral in any way what so ever. What the "neutral" is... is only a common reference point, which is tied to ground on a consumer service.

I prefer the terms "Line 1" and "Line 2" to "phases".

Rick...

Hi Rick,

You are right, I stated it that way for ease of understanding and as I stated it, it was inaccurate and misleading.

Shawn

As for the outlet, there are standard 220V US outlets for 15, 20 & 30 Amp. As Gwen mentioned I would go for the 20A which you would want to use 12 AWG Romex for, or equivalent.

Shawn

OK

Most of tips assume USA source and EU appliance.

Some formal intro:

USA standard residential voltage is 240-120 V ac and appliances have 230-115 V nominal values & 60 Hz frequency. Of course small appliances are connected to 120V outlets and large (stoves, dryers) to 240 V spec receptacles or terminal blocks.

System 240-120 uses at least 3-wire system (two hot /phases + neutral). Sometime there is the grounding 4th wire (green).

EU (if I remember) has generator's voltage 231 V and appliance voltage 220V, 50 Hz. Also 5- percent difference. UK: 240V

Connecting directly 220 V appliance to 240V US system creates some at least 5 percent overvoltage but probably will not harm the appliance.

Gentleman from Belgium is right. You MUST install a GFI(Ground-Fault-Interruption) protection with 20A receptacle which would be approved by an inspector.

I would add to the circuit an emergency switch to fulfill maintenance requirements if connection is done without receptacle+plug.

EU: The main voltage is 230/380V ±10%, 3 faze.

In our lab we test everything at 254V to have the overvoltage covered, and we are shifting to 277V to the IEC regulations, enabling one approval to cover the whole world. (IEC EX)

Bottomline we test at 190V for the 230V products.

Small correction:

three-phase in EU: 220/380V, 50 Hz for loads and 231/400 V for trafo and generators.

Single phase, of course 220 and 231 for apartments. UK..?

There are many "standard" voltages in USA. For plants/industries: 277/480 V, 60 Hz but also Delta 240 or 600 V. 5 percent diff. source - loads

I know that you know but I am giving small piece of info (trivia)

No one has mentioned that the line frequency is different over the world and you should check the device is rated 50 and 60 hertz.

It was:

EU has 50 Hz

USA 60 Hz

but in this case (no big motors) it is not important