3 phase instalation advice

[chrisg3103]

morning all, just a quick question about 3 phase instalation for any handy leckys out there.

just taken over a small unit and have a 3 phase incoming supply, only a single phase meter though. someone seems to have smashed there way into the meter to stop the little disc so landlady arranged to have it replaced, seeing as theres a 3 phase supply said to ask for a 3 phase replacement.

now, i have bought a 3 phase distribution board with 100A incommer, but is there a regulation saying there has to be a switchfuse before the board? or can the board be connected direct to the meter by mr meter man. need to figure it out by friday so i have the tails ready for him

will be next to the meter btw so no great distances between meter and board

 

[tigler]

As far as I know there is a regulation stating that there should NOT be a switch between the meter and consumer unit, so the meter has to be connected directly to the consumer unit.

 

[madkayaker]

No switch fuse needed unless tails over 3M

 

[Robotstar5]

No switch fuse needed unless tails over 3M

How do you isolate the board to work on it?

 

[NeilH]

i had 3 phase installed in my garage 2 weeks ago..

if the distance between the meter and the consumer unit is over a set distance (cant remember the figure) then there has to be a switch installed. thats what my electrician told me.

 

[mike os]

How do you isolate the board to work on it?

main swithc, same as always.... unless you need to replace the swithc then pull the service fuses.... better have a sparky on hand tho or the supplier can get a little squirrelly

 

[madkayaker]

South of haggis line a compitant person can pull fuses and reseal north of haggis line needs to be done by supply authorith new supplys tend to have isolation switch

 

[brightspark]

the mainswitch in the 3 phase db is the isolator in case u have to work on them . sometimes the board supply a 2 pole isolator switch to conect your mainstails to for single phase supply but dont on a 3phase .there conected direct .

 

[chrisg3103]

ta muchley chaps, save a bit of confusion.
just need to mount the board and locate some tails, one other quick note, cant seem to find colour coded 3 phase tails? online at least. only blue and brown, or is it just a case of having 3 brown and the blue neutral? (daft harmonised colour codes) cant find a black or a grey one

 

[the snooper]

some use all the same colour and just put the red blue and yellow tiewraps on the tails

 

[brightspark]

neutral blue .live one brown . live 2 black sleeve with brown tape . live 3 grey sleeve with brown tape

 

[brightspark]

ta muchley chaps, save a bit of confusion.
just need to mount the board and locate some tails, one other quick note, cant seem to find colour coded 3 phase tails? online at least. only blue and brown, or is it just a case of having 3 brown and the blue neutral? (daft harmonised colour codes) cant find a black or a grey one

if u are using 3 browns sleeve live 2 black and sleeve live 3 grey reet confusing isnt it

 

[madkayaker]

Or number 123 check what size earth the board want you to use standard is 16mm for 100A but have been asked for 25 before

 

[chrisg3103]

is a bit confusing preferd RYB, looks much nicer
just find an electric factor on monday and try and pretend i know what im talking about

currently have a 16mm2 earth on a the 100A sinlge phase supply, so thats what there getting, live's and neutral are 25mm

 

[brightspark]

is a bit confusing preferd RYB, looks much nicer
just find an electric factor on monday and try and pretend i know what im talking about

currently have a 16mm2 earth on a the 100A sinlge phase supply, so thats what there getting, live's and neutral are 25mm

for 16mm tails and below 16mm earth wire shall be used . 16mm to 35 mm tails 16mm earth wire shall be used anything over 35mm the earth cable shall be half the size of the live conductor

 

[madkayaker]

Main cpc is sized from n conductor for tails for tns systems ryb not alowed any longer

 

[chrisg3103]

quick followup this is how its ended up

replaced the ryb with some handy conversion stickers i found after taking that pic btw, so its all brown black and grey. see what mr meter mans got to say about it!

 

[brightspark]

quick followup this is how its ended up

replaced the ryb with some handy conversion stickers i found after taking that pic btw, so its all brown black and grey. see what mr meter mans got to say about it!

one thing needs changing put an inch and a half brass bush in the middle at the bottom . all incomer tails need to be in the same hole not drilled seperately as its a steel pate: and causes eddy currents :: tie wrap them together to tidy them up as well

 

[chrisg3103]

good grief, just read up on the possible side effects. shall get myself a 38mm brass bush, dont do inches
cables ok to be held with cleats or does there need to be a conduit run? not much support just having the plain bush

 

[brightspark]

a bit of 2x2 inch plastic trunking would be nice to stop mechanical damage and support it