12 way Ryfield board

[simselectrical]

Hi my name is karl of sims electrical contractors. I just started a block of flats and have to install a 12 way ryfield board via a 400amp a TP/N Isolator in a riser cupboard. What size tails should I install from isolator to ryfleld board. All to be enclosed into 6-6 metal trunking

 

[mainline]

Hi my name is karl of sims electrical contractors. I just started a block of flats and have to install a 12 way ryfield board via a 400amp a TP/N Isolator in a riser cupboard. What size tails should I install from isolator to ryfleld board. All to be enclosed into 6-6 metal trunking

Is that 400amp per phase ?

 

[westward10]

You are an electrical contractor have you not done some calculations.

 

[simselectrical]

Is that 400amp per phase ?

Yes 400amp per phase . It's only 3 metres from isolator to ryfield board

 

[simselectrical]

You are an electrical contractor have you not done some calculations.

Yes I've done calculations. I just asking for advice. I've put a 4 way ryfield before and had to put 35mm tails from cut out to ryfield. But this I'm installing a 400 amp TP/N
fuse isolator

 

[mainline]

Yes 400amp per phase . It's only 3 metres from isolator to ryfield board

What earthing system ?

 

[westward10]

You are limited to 240.0mm² for a Ryfield board of that size.

 

[mainline]

Yes 400amp per phase . It's only 3 metres from isolator to ryfield board

185 mm tails with 95 mm earth & 50 mm bonding on a PME earthing system was given by network power.

 

[simselectrical]

What earthing system ?

TNS

 

[simselectrical]

You are an electrical contractor have you not done some calculations.

Yes I will done calculations it's working out 185mm and 120mm earth

 

[simselectrical]

185 mm tails with 95 mm earth & 50 mm bonding on a PME earthing system was given by network power.

That's what I calculated but I'll install a 120mm earth

 

[simselectrical]

The 12 way ryfield will be sub mains to 12 x 100amp red cutouts to meters(being done by southern gas) From there I'll install 25mm 3 core swa to 12 D/Bs 1 being landlords then 11 flats