I came to think of the fact that I haven't ever shown what my fusebox at home looks like. As it is typical for many old homes in Sweden, I thought I could share a few pictures.
(A recent disk crash meant that I haven't got a decent photo editing software. Therefore, the pictures have the resolution they came out of the camera with. Big files = only links, no photos in thread.)
Diazed D1 fuses The fuses that fit in the main fuse box. "Old" and "new" design. Both still made. The "old" design is sold by electrical stores and carries no listing or brand name, only a "slow blow"-mark.
The "new" is sold by D-I-Y places and does carry both brand and listing. (CE, Swiss etc.)
Hi C-H. I've never seen those type of fuses used in a domestic fuse-box. Only in imported industrial equipment.
I'm guessing that the 4A, 10A, and 35A are for lighting, power outlets and cooker respectively. Is the 80A the main? Does Sweden have a system like the U.K. with ring circuits and fused appliance plugs and light fittings ?
Thanks for the pictures. Sorry about all the questions but I've never seen a Swedish fuse-box and they are quite different to ours.
The 80A fuse is found in mains for buildings or commercial/industrial settings. Never in a home unless it's a large farm or similar. DIV comes in sizes 80 and 100A only and is not very common as there are other fuse types competing for the market.
The 35A fuse is used like the above but also as main fuse for flats. It is the largest single phase supply and probably the most common. The cooker is then connected to a 25A fuse. DIII comes in sizes 32-63A and is common.
The 10A fuse is used for lighting and socket outlets. It is by far the most common size and type. It probably makes up 80% of all Diazed fuses in Sweden. DII comes in sizes 6-25A. (Other sizes on special order) These are the fuses seen above my meter. The design has proven to be very robust and reliable and even today, some sparkies stay with the Diazed fuses.
The 4A fuse was used for lighting and socket outlets in the 1930's and a few still remain in use. DI comes in sizes 4-16A. It can't be described as very safe: The screw caps are too larg for the fuses making them difficult to insert. The porcelain "socket" in the base of the box that prevents overfusing offers a better fit. You can remove the screw cap and the lightweight fuse stays in place - live! It is tempting to pull it out by hand...
My supply is on one of these. Originally 10A, the porcelain socket has been smashed to allow a 16A fuse to be inserted. As you can tell by the markings next to the fuses, the supply is 2.5 mm2. Two phases have been brought to the box but only one continues to the meter.
[This message has been edited by C-H (edited 08-29-2005).]
There are plenty of diazed installations still in use in Ireland. They were being installed as new right into the 1980s complete with RCDs... Many electricians were slow to change to breakers. Quite a lot of the smaller neater neozed fuses still in use too. In fact, all new panels still have a single neozed "main fuse" to protect the entire panel from overloads even with a modern MCB based panel.
In old installations with schuko outlets you'd have had 16A radials for sockets. I've never seen an unearthed outlet in use here so I don't know what fusing was used with them in the 1920s/30s... I'd assume 10A or less though.
If BS546 was used:
A few 5A sockets on a 10A diazed fused radial or a single 15A socket on a 16A diazed radial.
Later installations would have had multiple 15A sockets on a single 16A radial.
BS1363 sockets are installed on 16 or 20A radials.
[This message has been edited by djk (edited 08-29-2005).]
I've never seen DI fuses in real life... and DIV only once. A big municipial apartment building had D IV 80A fuses for the main feeder. Nowadays only a system called NH is used for such big fuses.
D IV isn't sold in Austria any more, which leads to interesting occurences... Around christmas (I think actually on 24th or 25th) a guy from the company where I had my summer job got called to a big apartment building at 7 am. No power in the entire house. First guess has to be something with the riser, otherwise at least parts of the house would have power. Opens the box... all three riser fuses along with the screw caps had been stolen during the night! Were lucky the pulled them during a low-load period... unscrewing such a beast under load must give a nice bang and fireworks!
Good screw caps have a spring inside that hold the fuse quite nicely. If that spring weakens I dump the screw cap. Good hardware stores still sell new DII and DIII screw caps, key rings and fuses, but the screw caps just look new, so I usually try to scrounge up old ones. That's not too hard, especially working for an electrician I could get several per day since we were ripping them out basically everywhere. During the four weeks I spent there I took out three complete Diazed panels.
Historically Austria never separated lights and sockets. There was one or more DII circuits for everything, depending on the size of the house/apartment. Before WWII usually 4A, later 6A, from the 1960ies onwards general purpose circuits were usually 10A. 16A was occasionally used for dedicated circuits, but mostly for deliberate overfusing. 20A and 25A are typical sizes for feeder fuses (1x 20 or 25A serves apartments up to 100 square meters quite nicely, 3x25A are usually enough for an older single family home. 35A and up are mostly used for big old single family homes and as riser fuses in multi-family buildings.