Three phase supplying a domestic flat.

[Fred Faulkner]

Hi guys,

i had a look at a building in the west end of london which is spilt into 10 flats this weekend to do some upgrading works to the landlord area.

i noticed that there was originally 6 flats and the landlord must of added an addition 4 flats on top. Called 10 9 8 7. ( obviously).

The issue is that there has been a 3 phase submain wired in swa from the ground floor ryefield board . Which is then terminated into a 3 phase board installed outside flat 10/9 . From this board they have wired the two flats using all three phases therefore giving a potential of 400v across the circuits installed into the flats!!

i.e
flat 10 1L1 - lighting
flat 10 1l2 - smoke alarms
flat 10 1l3 - sockets
flat 10 2L1 - cooker

flat 9 is the same i.e
3L1 lighting
3l2 smokes etc etc!

this senario is the same for flat 8 7 !

im sure this is hugely wrong!!!

 

[shanky887614]

Hi guys,

i had a look at a building in the west end of london which is spilt into 10 flats this weekend to do some upgrading works to the landlord area.

i noticed that there was originally 6 flats and the landlord must of added an addition 4 flats on top. Called 10 9 8 7. ( obviously).

The issue is that there has been a 3 phase submain wired in swa from the ground floor ryefield board . Which is then terminated into a 3 phase board installed outside flat 10/9 . From this board they have wired the two flats using all three phases therefore giving a potential of 400v across the circuits installed into the flats!!

i.e
flat 10 1L1 - lighting
flat 10 1l2 - smoke alarms
flat 10 1l3 - sockets
flat 10 2L1 - cooker

flat 9 is the same i.e
3L1 lighting
3l2 smokes etc etc!

this senario is the same for flat 8 7 !

im sure this is hugely wrong!!!

nope nothing wrong with it, there just balancing the load.

any electrician can tell at a glance it will be a polyphase board so whats the problem?

there shouldnt be a potential for 400v unless they use different phases for the lighting for example.

for example? using way 1,4,7 etc for lighting then there is no chance of 400v if mr diyer has a go himself

 

[Fred Faulkner]

nope nothing wrong with it, there just balancing the load.

any electrician can tell at a glance it will be a polyphase board so whats the problem?

there shouldnt be a potential for 400v unless they use different phases for the lighting for example.

for example? using way 1,4,7 etc for lighting then there is no chance of 400v if mr diyer has a go himself

Polyphase board meaning?

Its a 3phase TPN board. I disagree with you this isnt best practise for domestic installations.

there is potential for 400v if a diyer linked off the smoke alarm feed for lighting. There is potential for serious danger

 

[telectrix]

Polyphase board meaning?

Its a 3phase TPN board. I disagree with you this isnt best practise for domestic installations.

there is potential for 400v if a diyer linked off the smoke alarm feed for lighting. There is potential for serious danger

then he's no business messing with things he does not understand. anyway he's just as likely to die from 240V as he is from 415V. just that 415V might be a tad quicker.

 

[Fred Faulkner]

then he's no business messing with things he does not understand. anyway he's just as likely to die from 240V as he is from 415V. just that 415V might be a tad quicker.

Really good advice mate , why do you bother ?

 

[shanky887614]

Polyphase board meaning?

Its a 3phase TPN board. I disagree with you this isnt best practise for domestic installations.

there is potential for 400v if a diyer linked off the smoke alarm feed for lighting. There is potential for serious danger

poly as in multiple.

its not a problem, keep all lighting/smokes on same L and not a problem

 

[telectrix]

because i can. now. have a look on your regs book and find me a reg. that says it's wrong.

 

[Fred Faulkner]

poly as in multiple.

its not a problem, keep all lighting/smokes on same L and not a problem

As i said they are not on the same phase .

 

[Anthony S]

Really good advice mate , why do you bother ?

Read the post properly

 

[shanky887614]

As i said they are not on the same phase .

if its such a problem move the breaker

 

[Anthony S]

Hand the job back if your not sure

 

[Silly Sausage]

nope nothing wrong with it, there just balancing the load.

Not very well balanced, all the lights and cookers on L1 and just the smokes on L2!
Well thought out job there!!! :smilielol5:

 

[telectrix]

Not very well balanced, all the lights and cookers on L1 and just the smokes on L2!
Well thought out job there!!! :smilielol5:

it's in essex. what do you expect?

 

[colshaws]

The jobs in the west end, and whats wrong with essex:angel_smile:

 

[davesparks]

Hi guys,

i had a look at a building in the west end of london which is spilt into 10 flats this weekend to do some upgrading works to the landlord area.

i noticed that there was originally 6 flats and the landlord must of added an addition 4 flats on top. Called 10 9 8 7. ( obviously).

The issue is that there has been a 3 phase submain wired in swa from the ground floor ryefield board . Which is then terminated into a 3 phase board installed outside flat 10/9 . From this board they have wired the two flats using all three phases therefore giving a potential of 400v across the circuits installed into the flats!!

i.e
flat 10 1L1 - lighting
flat 10 1l2 - smoke alarms
flat 10 1l3 - sockets
flat 10 2L1 - cooker

flat 9 is the same i.e
3L1 lighting
3l2 smokes etc etc!

this senario is the same for flat 8 7 !

im sure this is hugely wrong!!!

It's unusual, but not wrong

 

[Guest125]

Leave Essex alone.

 

[TJ Anderson]

then he's no business messing with things he does not understand. anyway he's just as likely to die from 240V as he is from 415V. just that 415V might be a tad quicker.

That amuses me when people say that. Just cause three phase is present it does not mean they will receive a 415V shock. They will get L1 or L2 or L3 to earth @ 240V. Someone would have to be an absolute moron to put themselves across two phases to receive 415V.

 

[TJ Anderson]

i noticed that there was originally 6 flats and the landlord must of added an addition 4 flats on top. Called 10 9 8 7. ( obviously).

Got to be up pretty early in the morning to get one over on you hey

 

[telectrix]

That amuses me when people say that. Just cause three phase is present it does not mean they will receive a 415V shock. They will get L1 or L2 or L3 to earth @ 240V. Someone would have to be an absolute moron to put themselves across two phases to receive 415V.

trouble is, a lot of users are absolute morons

 

[Silly Sausage]

Got to be up pretty early in the morning to get one over on you hey

They could be Penthouse suites:

The Emma Clancy Suite, The Tony Cable Suite, ...

 

[telectrix]

They could be Penthouse suites:

The Emma Clancy Suite, The Tony Cable Suite, ...

i which case there'd need to be a rod with <100ohms Ra.

 

[Knobhead]

The load balancing is cr@p. If there’s ten flats with say 5 sub-boards the balancing should be coordinated across all boards. Not difficult if you take the time to work through it logically.

As for the 400V on lighting, unless the light switches for flat 10 are in flat 9 where’s the problem? As long as each flat is a separate entity there is no problem.

 

[trev]

Really good advice mate , why do you bother ?

How about, because he knows what he's talking about.

 

[Silly Sausage]

How the hell are they doing the metering?!?!

 

[Knobhead]

I was wondering that.

It can only be services included. It would be interesting if someone bitches about their share of the bill.