ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades 220/440V 2ph/3w service in Austria

These weren't even the "modern" Diazed II fuses, but the ancient Diazed I. Much smaller, with a maximum fuse size of 15A. When I found a store who still had 4A fuses in stock, the clerk refused to sell them to me. Instead he sold me 6A fuses and new "keys"... (He failed to convince me to go for 10A fuses)

No.

BTW. Do Austria use the TT or the TN-C-S system?

Now for Paul's comment:

I think it must have been used quite widely in Europe, since it has managed to spread to a number of former colonies.


A non earthed 230/400V system? I have never heard of such a thing. This of course doesn't mean it doesn't exist. AFAIK Norway uses both the standard earthed 230/400V system and a 230V unearthed system. The latter has 230V phase-phase and hence no neutral. The transformer is unearthed (a so called IT system) and the earth conductors are only used to prevent electric shock in case of a double fault. I.e. two appliances that has become live and are on different phases. By earthing the system a short circuit between the two appliances will develop, blowing the fuse(s). (The houses do have a earth rod and an RCD.) Unfortunately I know toolittle about this system to present any closer details.


Well, "ever been used" is a rather wague in this case. Everything that the twisted mind of an engineer can come up with has probably been used at one time or the other.

(The first Swedish generator refused to work since it had one earth conductor too many. It took days before they found the error.)


You can say that the UK has always been very down to earth when it comes to grounding...

{Edited only for brackets. Paul}


[This message has been edited by pauluk (edited 09-22-2002).]

ooops... Used wrong brackets! Moderator, feel free to correct!

Diazed 1? Don't think I've ever seen this.
When was it in use?
"6A fuses and new "keys"..."
I found out that 6A Diazed II fuses fit 4A keys. What wire size was used with the 4A ones? here in Austria I've only seen 6A ones with 1sq. mm cloth covered single wires (commonly overfused with 10A, I've also seen them fused with 16A, washing machine hooked up to them! The keys were replaced with 16A ones on one circuit and completely removed on the other one.)
TT, TN-C-S-System: I'm not an electrician, but I think both systems are used. Originally a seperate ground rod was required or the water piping was used as a ground rod and tapped for each Schuko receptacle (Have installed such a system myself in an appartment without ground at the panel, so at least the kitchen receptacles were grounded). Has been taken out of code 01/01/01 because of the increasing use of pvc water utility pipes.
PS: Did I mention that the appartment with the overfused circuits nearly burnt down while I worked there because of a loose splice on the line to the 2kw infrared bathroom heater? The wires were wound around a screw, secured with nut and washer and finally wrapped with PVC tape. This assembly started arcing on the phase in some junction box. Fortunately we heard the noises and screwed out the fuses.

C-H,
Brackets corrected for you! (By the way, you can edit your own posts if you wish by clicking on the little paper & pencil icon in the message header.)

It was only a passing reference I read to the Norwegian IT system some time ago, so it may well be just 230V 1-phase rather than 230/400V 3-phase.

The 127/220V system does indeed seem to live on in some ex-Colonial countries. We had somebody from Brazil in here a while ago and he still had 127/220 at his house, although other parts of the country are 220/380.

Tex,
On the earthing/grounding arrangements, if you look at the U.K. systems here, , diagram #1 is TN-S, #2 is TN-C-S, and #3 is TT.

The 1st letter indicates the grounding on the supply conductors (i.e. the neutral), "T" if solidly grounded, "I" if isolated or impedance-grounded.

The 2nd letter indicates how the protective ground is derived, "N" if it is bonded directly to the neutral, "T" if grounded separately to an earth rod.

The 3rd & 4th letters, if present, indicate whether the protective ground path is Separate or Combined with the neutral, or a combination of both.

("T" from the French "Terre" for earth).

By the way, what exactly are these "Diazed" fuses like? I'm assuming they're some sort of cartridge fuse, but it's not a name I ever recall hearing before.



[This message has been edited by pauluk (edited 09-22-2002).]

Ahh! There it was! Thanks! I'm one of those people who fail to understand symbols :-(


It's 230V 3-phase. (Yup, one voltage only. If they had used a neutral I suppose the voltage would have been 133/230V)


The name is rarely used. Usually they are called DI, DII, DII or DIV. (Increasing in size and rating)

The small DI fuses come in sizes from 4 to 15A, and were used in the 1920:s and 1930:s.

DII 4, 6, 10, 16, 20, 25A
DIII 35, 50, 63A
DIV 80, 100A.

Types DII and DIII are very common.

People also drive nails through the fuses or wrap them in copper wire.

I don't know the size, but I would guess at 1 mm2 or 1.5 mm2. The cloth brittle and starting to fall off. Oddly enough the wires were in pairs: i.e. one thin layer of cloth for each conductor and then another thin layer around both. A true nightmare when fitting a new ceiling lamp. Lots of electric tape and a prayer...

C-H thanks for posting the pics! I wanted to post something like this myself but couldn't get to it, glad you did this for me!
Yes these are common ways to get power when a fuse blows and no replacement is available. I've seen people pulling one strand out of an old cord and wrapping it around the fuse body.
Diazed II fuses are still pretty common here for residential/small commercial panels and are newly installed for appartment mains, DIII are used about everywhere for single family mains.
Thanks Pauluk for posting the link to the diagrams, yes, TN-C-S and TT are the systems used here.
In the 1920ies and 30ies (maybe earlier) we had fused receptacles here. The fuses were small cardboard strips (about 3/16" to 1") with brass sleeves on each end, the fuse wire visible through a round hole on one side. TWo of them (hot/neutral)were inserted into the receptacle. They were typically 1A (orange) or 2A (brown), though the color coding wasn't the least reliable. I've also seen 6 and 10A ones (the latter pretty useless as no receptacle was rated higher than 6A)
The only common wiring systems apart from the surface mounted knob and tube (2 rubber and cloth covered conductors wound together to a cord and mounted on glass or porcelaine insulators) were single wires, either directly plastered in (a nightmare) put in plaster and lath ceilings (even more of a nightmare, imagine one of these burning off, had this in our house some years ago!) or used in conduit mostly made of cardboard impregnated with some asphalt stuff, the better, though rare version with a very thin steel covering. These wires had a base rubber coating, then they were covered with cloth and finally impregnated with smelly asphalt. 1. sq. mm solid tinned copper conductor. Today some of these are still in decent condition, but most on of them the rubber crumbles away, especially were they are exposed, e.g. where they come out of the ceiling. As about 3/4 of Vienna's houses are pre-WWI this stuff is used and abused about everywhere. I once got bit when wetting a wall to remove wallpaper because of those wires. I didn't even know there were wires in that wall, they were abandoned, yet still hot!
In the 50ies PVC covered wires came up.
The wire type I like best is something like double-sheathed zip cord with more space between the conductors, directly buried in plaster. It's very easy to handle (way easier than modern stubborn round Romex, which is listed for the same use). It's still available, but for 73 cents/metre (roughly 3ft) compared to 8 Euro ($8) for a 50m (165 ft) coil of Romex, i. e. 16 cents /m

The illustrations and discussion about the Diazed fuses answer some longstanding questions. About 10 years ago I was called to a machine shop hi-bay room that contained an PLC-controlled lathe with an ~eight-foot bed, and the control console contained about half-dozen sets of Diazed fuses in the range of 1-to-63 amp…a control power transformer to semi-fat motors.

The machine was sporadically frying Omrom-brand open-board PLCs. The regional vendor was happy to provide ~$1100 boards for replacement.

The building’s service was via a then-new padmount 300kVA secondary-unit substation with 480V 3-wire ∆ ungrounded secondary windings…an accepted {and somewhat popular} practice in the US.

Console was furnished with a ~250VA control-power transformer rated 440-to-220V and not until another failure was it realized as being an autotransformer, even with four leads connected {two were strapped common on the opposite side of its integral terminal block.}

The phase voltage was well balanced, but routinely peaked at around 490V at night. PLC was labeled for 200-220V, but transient voltage-to-ground could be way beyond that with the autotransformer lack of isolation. That’s what happens when widely differing ”routine and expected” practices collide.

The permanent fix was to install a pair of 150VA 480-to-120V control-power transformers in open-delta [3ø 3-wire 480V] primary to open-wye [208V “1ø” 2-wire wye-grounded] secondary arrangement. This kept PLC power at 215V maximum, but more significantly it was now isolated and solidly grounded.

Not having the correct spare parts, the “DI” 1-ampere fuse pair was replaced with a 3-pole cartridge-fuse pullout block. The new configuration provided isolation of PLC power from the building 480V system, curing the recurring damage.

Thanks for the diagrams -- I've seen those bottle-shaped fuses before but had no idea what you called them on the Continent.

Unfortunately, a couple of strands of wire from a flexible cord are also sometimes used to bridge the cartridge fuses in our 13A fused plugs. Aluminum kitchen foil is another favorite, although that seems to be more common on the fuses in cars.

C-H, I don't like icon-based systems either, but then I grew up using computers pre-Windows!

>
>The wire type I like best is something like
>double-sheathed zip cord with more space
>between the conductors, directly buried in
>plaster. It's very easy to handle (way
>easier than modern stubborn round Romex,
>which is listed for the same use). It's
>still available, but for 73 cents/metre
>(roughly 3ft) compared to 8 Euro ($8) for a
>50m (165 ft) coil of Romex, i. e. 16
>cents /m

16 cents/m? Is this 1.5 mm2 three wire? Hell, I pay 80 cents/m for that!

I've got an idea: A common cable type for entire Europe. Or rather three different:

1.) Plastic cable
2.) Cable with metallic shielding
3.) Cable with reinforced metallic shielding for direct burial.

All rated for 450/750V, stranded wires only, rated for 90°C. Preferably of some plastic that can stand sunlight and be used directly outdoors. (Smallest size 1.5 mm2)

Stranded only since solid wires are difficult to work with and easily broken when repetedly connected and disconnected.

The 90° would give about 20% extra current carrying capacity compared to 75°C cables. Hence, 2.5 mm2 could almost always be used for 20A, even when the cable had to be derated.

The price would be low thanks to the huge quantities sold.

[This message has been edited by C-H (edited 09-23-2002).]