Electrical fault - who's liable for damaged appliances?

Badger_Lady

Hia,

I'm writing on behalf of my housemates... we're in a very large building that's being 'reused'. We are not full tenants but do pay rent to live there.

Anyway - yesterday there was some kind of electrical fault in the building, where 400V were found in some rooms. Appliances with internal fuses blew them out, and chargers / small appliances simply broke from the surge.

I was lucky enough to be unaffected by this - mostly because I have only one appliance that I leave plugged in - but there are around 60 people who are now finding themselves impacted.

So, without knowing where the fault came from, where does liability for these appliances lie? Is it with the occupants, the building owners or some other party?

spadoosh

I would guess with the occupants but like you said you dont know where the fault is from. I dont understanad the 400w bit?! 400w isnt really alot and most plug sockets can carry more than this.

Id be suprised if most of the appliances dont say they should be plugged in an RCD beforehand aswell.

Badger_Lady

spadoosh wrote: »

I dont understanad the 400w bit?!

Sorry, wrote it in a hurry - I meant 400 volts!

Hintza

Who or what caused the surge? Until you know or can prove that you will have to claim from your contents insurer.

Badger_Lady

Hintza wrote: »

Who or what caused the surge? Until you know or can prove that you will have to claim from your contents insurer.

I don't think it's very likely that anyone will have contents insurance... or even that an insurer would cover us in our strange living situation.

DVardysShadow

Badger_Lady wrote: »

Sorry, wrote it in a hurry - I meant 400 volts!

Hintza wrote: »

Who or what caused the surge? Until you know or can prove that you will have to claim from your contents insurer.

A 400V surge is almost certainly a broken neutral connection in a 3 phase supply. What you need to find out is how the neutral connection became broken. once you know that, you will know who if anyone is responsible.

Badger_Lady

DVardysShadow wrote: »

A 400V surge is almost certainly a broken neutral connection in a 3 phase supply. What you need to find out is how the neutral connection became broken. once you know that, you will know who if anyone is responsible.

Thanks DV... what are some ways that it could become broken? Is it likely to be a physical action, or could it be related to works currently being done in the street opposite (large scale building work)?

Is it at all possible that an occupant could have mistakenly caused the fault by plugging in a dodgy appliance?

spadoosh

DVardysShadow wrote: »

A 400V surge is almost certainly a broken neutral connection in a 3 phase supply. What you need to find out is how the neutral connection became broken. once you know that, you will know who if anyone is responsible.

Completely off topic but i swear i mustve had a dream about you last night, i woke up this morning and all i had going round my head was 'dvardysshadow'

Is there a famous context and possibly a harris assosciated to this?!

If not please completely ignore your local internet loony!

DVardysShadow

Badger_Lady wrote: »

Thanks DV... what are some ways that it could become broken? Is it likely to be a physical action, or could it be related to works currently being done in the street opposite (large scale building work)?

Is it at all possible that an occupant could have mistakenly caused the fault by plugging in a dodgy appliance?

The neutral connection is usually broken by someone doing some electrical work and disconnecting this apparently useless connection which does 'nothing' in a 3 phase system but is essential to running single phase [domestic] systems on a 3 phase system. Sometimes the neutral conductor burns out but this is very rare

http://en.wikipedia.org/wiki/Three-phase
http://en.wikipedia.org/wiki/Three-phase_electric_power
for more info, but it is baffling unless you can see past the maths. The basic idea is that AC electricity goes positive and negative in a sine wave. And if you have 3 sine waves delayed by 1/3 of a cycle with respect to the last one, the return currents add up to 0, which has technical advantages [one return conductor does the job of 3 and the currents add up to 0, meaning less losses in the system]. But with domestic supplies, 60 flats will be spread 20 on each phase. But if any phase is lightly loaded, that phase will tend to go towards 400V, thus blowing the equipment and making that phase more lightly loaded and exacerbating the problem.

Whoever told you 400Volts has heard from someone who knows what happened

It is all rather technical

Badger_Lady

DVardysShadow wrote: »

The neutral connection is usually broken by someone doing some electrical work and disconnecting this apparently useless connection which does 'nothing' in a 3 phase system but is essential to running single phase [domestic] systems on a 3 phase system. Sometimes the neutral conductor burns out but this is very rare

http://en.wikipedia.org/wiki/Three-phase
http://en.wikipedia.org/wiki/Three-phase_electric_power
for more info, but it is baffling unless you can see past the maths. The basic idea is that AC electricity goes positive and negative in a sine wave. And if you have 3 sine waves delayed by 1/3 of a cycle with respect to the last one, the return currents add up to 0, which has technical advantages [one return conductor does the job of 3 and the currents add up to 0, meaning less losses in the system]. But with domestic supplies, 60 flats will be spread 20 on each phase. But if any phase is lightly loaded, that phase will tend to go towards 400V, thus blowing the equipment and making that phase more lightly loaded and exacerbating the problem.

That's amazingly helpful, thank you! :j All our information has come from the electricians who were in yesterday trying to fix it. They also said that they thought "the main ring had overloaded and melted, with the result that the fuses did not trip / are not tripping". Does that help with theories?

At the same time yesterday there was something of a gas scare that was related to the street works - at one point we thought we would have to be evacuated, but luckily the scare was over very quickly.

DVardysShadow

Badger_Lady wrote: »

That's amazingly helpful, thank you! :j All our information has come from the electricians who were in yesterday trying to fix it. They also said that they thought "the main ring had overloaded and melted, with the result that the fuses did not trip / are not tripping". Does that help with theories?

At the same time yesterday there was something of a gas scare that was related to the street works - at one point we thought we would have to be evacuated, but luckily the scare was over very quickly.

'The main ring overloading and melting' is a completely misleading description for a broken neutral. I have seen in happen once [it was impressive hearing capacitors go pop in computer monitors and small puffs of smoke out of the backs]. But it is so rare that many electricians might not recognise it for what it was. Strangely, the first thing I was told about it was 'The main circuit overloaded and melted' although I knew it was a broken neutral - only when I probed, was it admitted that someone had unbolted the neutral at the supply point.