Replacing a dual tariff supply consumer unit

[AdamSmith86]

Afternoon all,

I have been asked to change a consumer unit with a dual supply. I have a common supply, an off peak supply and one neutral, all 16mm double insulated tails. The current set up has the neutral running to the first isolator and then looping from there to the off peak isolator (2 16mm tails in the same terminal).

I'm not sure I would be happy running the neutral in the same manner in a new consumer unit (Please tell me if I'm being overly cautious. Most isolators have cage clamp terminals so may well be fine) so was wondering if anyone knew of an off the shelf solution to install. I'm thinking something that would maybe allow me tee off from a dedicated neutral bar with a couple of cables, each with there own separate terminal. Oh and it has to be no more than 200mm tall as it is going above the front door! (gotta love the wisdom of flat designs back in the day!). The only thing that has come to mind so far is getting a split load board and installing 2 isolators, RCBO's and using the usual high integrity neutral bar to split the incoming neutral (I wall assume my position in front of the firing squad if that one is way off the mark!)

Your help is very much appreciated

 

[snowhead]

Where does the single neutral originate, Dual rate meter or 2 separate meters or Henley or Cut-out or ??

 

[westward10]

Just split it at a service terminal block.

 

[AdamSmith86]

Where does the single neutral originate, Dual rate meter or 2 separate meters or Henley or Cut-out or ??

It comes from a digital eco 7 meter in a Mantel unit in the hall outside the flat. There is a neutral from the cut out to the meter and one neutral exiting on the way to the consumer unit. I'm not sure I'd be allow to run a secondary neutral in trunking out in to the hall as that's the freehold's manor!

 

[pc1966]

Could you use a 4-pole isolator for 3-phase as basically 2 * 2-pole isolators for dual single phase, or have I misunderstood the problem?

 

[AdamSmith86]

Could you use a 4-pole isolator for 3-phase as basically 2 * 2-pole isolators for dual single phase, or have I misunderstood the problem?

That would still require daisy chaining the neutral out of one of the isolator terminals which I think I need to avoid.

 

[pc1966]

True, but typically they have clamp connections that take 35mm cable so would be no problem for 2 * 16mm.

You could use a Henley block to split them first, then the 4-p isolator so both supplies (and related neutrals) go off in one go.

Probably could get a 4-p switch for the CU but might need to check with the manufacturer (unless they list one) to be sure it is compatible with any internal bus bar arrangements.

 

[AdamSmith86]

True, but typically they have clamp connections that take 35mm cable so would be no problem for 2 * 16mm.

You could use a Henley block to split them first, then the 4-p isolator so both supplies (and related neutrals) go off in one go.

Probably could get a 4-p switch for the CU but might need to check with the manufacturer (unless they list one) to be sure it is compatible with any internal bus bar arrangements.

Also have the added annoyance of the meter being separate from the flat and in the communal area of the flats. I would need to get the ok from the freehold to start screwing up trunking in the hall and running cables. Maybe that would be the way to go. Freeholds are rarely helpful in my experience!

 

[Lister1987]

Any chance of some images?

 

[AdamSmith86]

Any chance of some images?

Sadly not, sorry.

 

[snowhead]

A single pole Service Connector should easilly fit inside the Dual Rate C.u. to allow the Neutral to be split

100A Single Pole Connector Block

Heavy duty service connector blocks for use at meter and mains positions

www.cef.co.uk

 

[AdamSmith86]

A single pole Service Connector should easilly fit inside the Dual Rate C.u. to allow the Neutral to be split

100A Single Pole Connector Block

Heavy duty service connector blocks for use at meter and mains positions

www.cef.co.uk

That could be a good shout actually, thanks!