isolator required or not?

[betty swollocks]

small commercial premises with 3phase supply but only single phase meter at present, being upgraded this week.

i've installed a new 3phase db which at present has no outgoing circuits

and my question is

do i need to install an 3p isolater between meter and db?

distance between each is 1m

or will dno connect tails directly into meter?

thanks in advance

 

[Dane]

When they did mine, they insisted on a isolator between the 2.

 

[septiclecky]

small commercial premises with 3phase supply but only single phase meter at present, being upgraded this week.i've installed a new 3phase db which at present has no outgoing circuits

and my question is

do i need to install an 3p isolater between meter and db?

distance between each is 1m

or will dno connect tails directly into meter?

thanks in advance

How are you going to isolate the DB if you need to work on it without having to pull the DNO fuses?

 

[Dane]

How are you going to isolate the DB if you need to work on it without having to pull the DNO fuses?

the isolator built into the board.

What he is asking, is Does there need to be a "main" fused isolator between the Meter and the Board.

When we had out 3 phase connected They insistad we had a 3 phase isolator that is Fused between the Meter and Board. Believe its 80amp, and the DNO fuses are 100Amps.

Please correct me if im wrong, only going off experience, i dont do 3 phase work normally.

 

[Apache]

the isolator built into the board. What he is asking, is Does there need to be a "main" fused isolator between the Meter and the Board.

When we had out 3 phase connected They insistad we had a 3 phase isolator that is Fused between the Meter and Board. Believe its 80amp, and the DNO fuses are 100Amps.

Please correct me if im wrong, only going off experience, i dont do 3 phase work normally.

Pardon me, is that 3*80A fuses?

 

[Dane]

Pardon me, is that 3*80A fuses?

yes 3 x 80amp. This is what the said we must have.

 

[septiclecky]

the isolator built into the board. What he is asking, is Does there need to be a "main" fused isolator between the Meter and the Board.

When we had out 3 phase connected They insistad we had a 3 phase isolator that is Fused between the Meter and Board. Believe its 80amp, and the DNO fuses are 100Amps.

Please correct me if im wrong, only going off experience, i dont do 3 phase work normally.

Where does it say that as if it is a fuse board and not an MCB board it won't have an isolater.

 

[betty swollocks]

new db has its own built in 4pole isolator

 

[Dane]

Where does it say that as if it is a fuse board and not an MCB board it won't have an isolater.

If its a NEW DB Board, it will/should have a 3 or 4 Pole Isolater Fitted.

 

[Andy™]

i wouldnt bother with the isolator. just install a TPNE board in my garage the other week, no isolator between meter and DB

 

[batty]

SSE usually put isolators in EDF don't but you should not need an isolator as you have the main switch its no different to a consumer unit.

Batty

 

[septiclecky]

If its a NEW DB Board, it will/should have a 3 or 4 Pole Isolater Fitted.

GEC Alstrom Red Spot DB's require a seperate isolator

Have a look at this Picture

http://www.scatts.co.uk/pdf/196-1.pdf

 

[bigclive]

I'm going to be pro-isolator here. Even though the main DB has one itself, it's useful to have an external one to allow future upgrades including addition of other DBs without having to pull the boards fuses.

 

[Evans Electric]

Unless things have changed in the last 500 years they will connect your tails directly to the meter. The isolator in the Db will be the main switch for the building .

Deke

 

[green-hornet]

I always use the main switch in the section board or db its just the same as a main switch in a domestic cu.

Only problem arises if the local dno insist on one being fitted, but for three phase I would not like to fuse each phase especially if its a 400amp or so supply.