Main earth bond commercial..

[bigspark17]

DnoSupply is
400amp
185mm2
three phase 4core

what should the main earth bond size cable be.? Which part of regs will point me in right direction?
Thanks

 

[Guest77]

DnoSupply is
400amp
185mm2
three phase 4core

what should the main earth bond size cable be.? Which part of regs will point me in right direction?
Thanks

120mm2? what do you think fella?

 

[bigspark17]

Sorry do appologise just read my post.. I can get my main earth size from adiabatic table.. My question was for main equapotential bond to water incomer.?

 

[Simonslimline]

Edit...

BS7671. 544 Protective bonding conductors.

 

[tony mc]

What is the earthing arrangement ?

 

[Darkwood]

Vital info missing see post 5.

Although your 3ph 4core comment suggests TNS or is this misleading us?

 

[bigspark17]

Its a tn-cs.. Thanks for your info.!

 

[jonney88]

544. says with tail size greater than 150mm maximum equipitential earth size is 50mm and s/2 for your main earth bonding there only need 95 120 is over sized