New CU - how many empty ways for future

[jase31]

On a new cu install, how many empty ways would you leave for future expansion? i.e fill a 10way - or put in a 12way with two empty?

 

[Goody]

If there are 6 or 7 circuits I would go for a 10 way board. Can't find anything on the "Big Green Book" about this but in my opinion 2 empty ones would suffice.

But I would ask the landlord if he has any future plan for additional circuits.

Cheers!

 

[ElectricalAsh]

I'm sure that I've read a reg that states a percentage for future expansion although I never install a C/U without spare ways. sure someone will correct me if I am incorrect.

 

[Marvo]

We try to allow 30-50% spares in a commercial panel. It's never ceases to amaze me how many spares have been used when we go back to the customer after a year or two.

 

[Deleted member 26818]

Depends on the installation, what kind of board you're installing and what's been covered.

 

[Engineer54]

On a Domestic installation leaving a couple of spare ways is normally good enough. On a commercial/industrial installation, it's a common requirement and always good practice to have at least 25 to 30% spare capacity throughout the installation...

 

[Knobhead]

On a Domestic installation leaving a couple of spare ways is normally good enough. On a commercial/industrial installation, it's a common requirement and always good practice to have at least 25 to 30% spare capacity throughout the installation...

Always a good question this and one I’ll guarantee you won’t get right. All I can say is best of luck to you!

The companies I’ve worked for failed miserably in the past. OK it's on a bigger scale one particular plant I worked on was designed on a shoestring. Within 2 years we had to put in an extra 1MVA supply, then 5 years later yet another 1MVA. The switchboards were a nightmare of bits cobbled together to extend them.

 

[MarkieSparkie]

In a domestic installation, I like to leave at least 2 ways blanked off for further expansion.

 

[Octopus]

I've just finished a rewire on a bungalow and have used a 10 way board - yet only used 6 ways. My thinking was that the "loft" is ideal for 2 bedrooms and a shower room so 3 more circuits could easily be used.

 

[clicon357]

Don't forget spare ways for the sauna and hot tub!

 

[needasparks]

I seem to remember it being 10% spare capacity. But the bit i can't remember is where i read it............?

 

[davie spark]

Come on mate ! for the sake of '2 ways' ? Get the 12 way installed.

 

[Jay Sparks]

Ive just done a cu change and there was only 5 circuits but I fit a 10 way dual rcd board. Couple of reasons for this, firstly the customer says at some point he wants to put electrics in his two sheds, he also wants to put lighting in the garden, the second reason is that screwfix was doing a deal on a 10way dual rcd board that came with 10 mcbs for £69. I priced up an 8 way board, dual rcd, with mcbs and it was nearly £100. So the choice was a no brainer, the customer has 5 spare ways for future installs and I got the job cos the quote was cheaper.

Jay