3 phase domestic.

[gjcone44]

A customer is having a 3 phase supply installed, replacing single phase supply, becouse he has built a work shop, 100mts at end of his property, and has some 3 phase, equipment, not a lot , a car ramp , and weilder, the supply for that(ive been reading the do,s & donts for exporting pme.) but thats something to think about later?, my problem is, at the moment he has, a 100amp fused isolator, single phase. Which is above the single phase meter, the main dist/board, is in another room 5mtrs away. There is no room to fit a 3 phase isolator, at the postion of the meter, infact next pos postion, is 5mts away. Space above meter is 11 inches x11 inches, tails would have to come out of meter, and run 5mtrs, would this be ok?

 

[Guest123]

You would have to consult the DNO to see if they would guarantee their service fuses at that distance.

The distances do vary between DNO's typically between 3 & 4M, you may be lucky and they will ok.....or you may not in which case you will have to shoe horn a switchfuse in next to the meter somehow.


Could you not fit an external meter cabinet and move the meters outside leaving you with more space inside behind the meter box for a switchfuse???

 

[gjcone44]

THANKS FOR REPLY, LENNY, THIS IS ACTUALLY IN A CELLER, THE METER BOARD SI ALREADY OVERHANGING, A VOID, (LOOKS LIKE A OLD ARCH, RECESS) WICH HAS GOT A GAS METER INSIDE. THIS RECESS, GOES RIGHT UP TOO CELLER DOOR GIVE OR TAKE A FOOT, ALSO MAINS WATER COMES IN THRU RECESS, THATS ALL TO THE LEFT, AND TO THE RIGHT HE HAS 3 GAS BOILERS, AND UNDERNEATH, HE HAS OLD TYPE SINK AND WASHING MACHINE.THERE IS NO ROOM FOR 3 PHASE S/W. THING IS HE"s GOT THEM BOOKED IN FOR NEXT WEEK 5 APRIL.

 

[Dunc]

I'm sure I was taught at some point that tails to a consumer unit must be 3m or less if unprotected however if you install them in steel conduit longer runs are permitted without additional fusing. Anyone else heard this or am I imagining things? I'm assuming the conduit must be bonded though but that goes without saying.

 

[Deleted member 26818]

The 3m rule is because of the reduction in current carrying capacity of the conductor.
Nothing to do with the containment, other than such may reduce the current carrying capacity further.

 

[gjcone44]

will have to speak to dno?, i think the best option would be to move meter outside but it will cost him, at the moment, he said they are only charging him £60.00, a 3 phase cut out is already there.