ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Will an American 2-pole brkr function properly if wired to a European 220v 50h sys ?

Yep, that's called 1+N breakers. They only fuse the phase but also switch the neutral upon tripping (older types were actually obviously 2 devices in 1 case with only 1 handle). Autria (or at least Vienna) uses them extensively. We even have 2 fuses in older installations.

I've never seen a 1+N breaker. Two pole yes. Where do you find these?

At each and every hardware store in Austria. You'll find 2 racks side by side, 1 with single pole breakers, 1 with 1+N. About twice the price, but strongly recommended (if not even required). Saves the need for a neutral bus in the panel and makes split arrangements with more than 1 RCD much easier.

When we had DC mains, I've read that sparkies used to fuse both legs of the circuit (positive and negative). This makes sense.

However, this practice carried over to AC where sometimes the hot and neutral were fused instead of just the hot. What happens when your "neutral" fuse blows but your "hot" fuse stays closed?

That could be a bit of a problem....from a safety point of view, especially if an ignoramus DIYer pulls the "neutral" fuse to do a repair and leaves the hot in place

[This message has been edited by SvenNYC (edited 05-14-2003).]

Ragnar,
if it's twice the price I fail to see the point of not making them real breakers. Are you sure it isn't a double pole breaker? In case of a fault on the live it also switches the neutral.

Just because it says L and N on the terminals, it doesn't have to mean that it matters electrically.

(Sorry if it sounds like I'm attacking you. Not my intention)

We used to have double-pole fusing in Britain back in the 1930s. Nowadays, the regulations permit a circuit breaker to be inserted in the neutral, so long as it simultaneously breaks all phases. Double-pole isolation switches are quite common for ranges, fixed heating units, etc.

Even though the "regs" permit a C/B to open the neutral, it's not common in the U.K., except for RCDs (GFIs).

I would like to say that:

1, We always use double pole (or 3+N) breakers.

2, The breakers fuse the phase as well as the neutral.

3, It always breaks simultanously all poles.

4, When using 3+N breakers then the neutral opens a fraction of a second later and upon closing, a fraction of a second earlier.

5, The reason that we are required to use double pole breakers is because a lot of regions are still the old Y230/120 systems. In those regions only the two phase (or eventualy 3 phase) are delivered to the consumer, therefore getting 230V. Therfore all the phases have to be broken.

I keep thinking about that too, but there are definitely 1N and 2P breakers available. 127/220V was used here until about 1975, so the 2 fuses of the old wiring make sense. Probably this was just kept until today. It definitely makes tracing of neutreal-to-ground faults much easier since you can isolate each circuit by just turning off the breaker.

Ragnar could be right:

C-H, How come you call Ranger Ragnar? Is this his real name?
Anyway, Ranger is right but I am, too. Here are some pics.
The footnote 1 of the first pic describes that the Neutral is thermicaly and magneticly fused and that it shuts before and opens after the other phases.



[This message has been edited by Belgian (edited 05-16-2003).]