ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Austrian Diazed Panels

here are even 2 fuses used.

Main Line connection - 50/63A NH - 35A Neozed before meter - RCD - MCBs

Doesn't having a Neozed before the meter make it easy to bypass the metering completely?

It's occasionally done, but not very often. Here in our old apartment building you usually have 3 60A NH fuses in an enclosure outside the building and a set of 2 or 3 Diazed fuses for each apartment (usually located inside a fuse box on each floor) ahead of the meter. The wiring from the fuses to the meter is not to be spliced, though _no one_ checks on that. Most hacks involve cutting into those wires somewhere during the run of the old cardboard conduit, splicing into them and replastering the area. if you do the plaster job well enough it'll never show until somebody decides to replace the feeder. It's not even dangerous since you can easily unscrew the fuses (they've got to be accessible, with today's power requirements those 20 or 25A fuses blow from time to time). overcurrent protection is a bit of an issue since your 1.5mm2 wire will only be protected by a 20 or 25A fuse. And installing another set of fuses would raise some suspicion I guess!

The main fuses are ahead of the meter in Sweden. People sometimes smash the glass, put wires in the fuse holder and then pick up a neutral somewhere else.

The problem really is the fact that the meter is located at the customers premises. In my humble opinion, it should be somewhere else where people can't tamper with it.

The irish system has a sealed service fuse that you can't remove without breaking a very large sealed tag which is very visible everytime the meter's read. It's also why the ESB requires all of the cables to be visible on the board where the meter's mounted rather than hidden behind it. The meter reader's supposed to visually inspect the installation to make sure that all of the seals are intact and that only 2 cables enter and leave the meter.

However, people did get around meters the most common trick in the old days was to remove the screws that held the wooden panel that meter was mounted on and tilt it over to about 45 degrees. The old meters couldn't work if they wern't completely level so would stop counting units. I've also heard of tricks with magnets etc. used to disrupt the metering

They simply started sealing the board making it impossible to remove without breaking very obvious seals.

Group meters can sometimes be used to verify the accuracy of customer meters by metering the entire supply to a number of premises and if someone's really suspected of fraud they can even install a pole-mounted meter to gather evidence.

I once thought of using the screw trick in order to relocate the meter w/o having to dump the cool old wooden meter board. However, the wiring was in such a bad shape I decided to do the job right.
A common way to stall meters was to drill a hole through the disc and push a wire (paper clip, ect) through the disc. Only problem: the meter readers weren't that dumb they didn't notice the hole in the meter...
Modern meter bases have three mounting screws, one opf which is hidden benath the meter's terminal cover. Impossible to get such a meter off the wall, unless you try ripping the anchors out of the brick wall, hoping the sparky who installed it drilled into a mortar joint and didn't bother using moltofill. Even some of the old wooden boards simply got a new hole drilled. I still have two of the real old boards lying around, the electricians just dump them when taking them out.

BTW, some of these (or even most residential ones) weren't flush like the ones in the pics but screwed to the wall on 2cm porcelaine distance blocks. Most people built a custom cabinet around it, but not all. Sometimes you'll still come into an apartment and see in the hallway a meter on a wooden board and below or above 2-4 10A Diazed fuses. Upgrading those panels usually means taking down the old Diazed panel and replacing it with a surface-mount DIN rail one.