I'm in the middle of a discussion (read arguement) over the proper way to disconnect 220vac 1ph, in an electrical panel I'm designing to be installed in Italy. 220vac 1ph is being brought into my panel, which after going through a branch circuit protector, will be distributed to a series of dc power supplies. My question is, should I use a 2pole or single pole breaker for each of the power supplies? I'm thinking I need a 2pole breaker, but the other engineer believes I only need a single pole breaker. Won't I still have a potential of 110vac on the other leg if I only break one line of the 220? Could someone also point me to a place where I can find this info for myself?

Thanks,

It depends.

Like other European countries Italy uses 230/400V 3-phase. That means that the voltage from phase to neutral is 230V. This only requires single pole breaking, in theory.

To make things complicated there are two more things.

1.) The Italians may require you to use all pole breakers, breaking the neutral too. France and Belgium does, most other countries don't.

2.) The Italians might still have the (127)/220V system in use. (Or if it's (133)/230V today) Some other countries do, including Belgium and Norway. In this case only the phases are brought in, and single phase loads are connected between the phases, requiring a double pole breaker.

It is extremely unlikely that anyone will complain if you use double pole breakers, as long as you can separate the equipment ground from the neutral. (Just like in the US)

Please note that European breakers are not the same as the American. (Europe uses the international standards (IEC 60898, IEC 60947), unlike America where each manufacturer has its own models)

Also note that your setup will need a CE mark. If you are using equipment that lack CE mark, you are assuming responsibility for it when you mark your product. (If e.g. a CE marked breaker catches fire, you point to the manufacturer saying "It was his fault, not mine") If you don't mark it, the installer/electrician will have to assume responsibility for your equipment.

C-H,
Is that true about the CE mark?.
I thought that the CE mark, was purely and simply to show that the product was made in Europe.
How wrong can I be?.
So it's an approval mark, like VDE, Kema and the like?.

A little late, for which I apologize, but I'll echo C-H's comments.

I don't know if Italy's standards require a double-pole C/B which opens the neutral. France certainly has gone that route in recent years, although here in Britain a single-pole breaker would be acceptable if the other side of the circuit is grounded.

If the 220V is from two legs of an old 127/220V 3-phase network, then double-pole would be required.

Trumpy,
The real meaning of CE has been kept secret from you.

CE = Confusion Everywhere!

Trumpy,

yes. But unlike VDE, Kema-Keur etc. which are volountary, the CE is the legal requirement. For everything, not just electrical. It's on everything that can be unsafe. Machines, drugs, contact lenses, protective glasses, gas masks and you name it.

Conformity Everywhere

I'm late too!

The CE Mark must be applied to all products that fall under the New Approach Directives. some of those Directives that probably apply to you are; Machinery, Low Voltage (any thing with an input of 50 VAC/75 VDC or greater) EMC ( radio Frequency emissions and Immunity for all electrical equipment), Pressure Vessels, Medical devices, protective wear, Toys and Explosive atmosphere (haz Loc). There are many others but these are the ones that might effect us.

The CE Mark has to be applied to any products that fall into the scope of the mentioned Directives. It's mandatory if the product will enter the EU market place. It dosen't matter if the same company issue a peice of equipment to a sister company in Europe, once it enters Europe it must conform. There are many court cases going on right now and the list is growing.

Usually your worsed enemy is your competitor. They are the first to buy your product and then have it challenged by the local agencies. It helps them to market their product while you have to go back through certification process. It can be quite time consuming and expensive if a challenge is made. At this point there is no cutting corners you must cross every "T" and dot every "I" to prove compliance.