SIZING FOR GROUNDING GRID CONDUCTOR

[TMMB]

I HAVE A BUILDING 35X19 m , total connected loads : 650KVA , how can sizing the grounding grid conductor (around the building), VOLTAGE SYSTEM IS 380V, 3PHASE , 60HZ

PLEASE ADVICE

REGARDS

 

[Smart $]

I HAVE A BUILDING 35X19 m , total connected loads : 650KVA , how can sizing the grounding grid conductor (around the building), VOLTAGE SYSTEM IS 380V, 3PHASE , 60HZ

PLEASE ADVICE

REGARDS

See following excerpts...

(4) Ground Ring. A ground ring encircling the building or structure, in direct contact with the earth, consisting of at least 6.0 m (20 ft) of bare copper conductor not smaller than 2 AWG.

(F) Ground Ring. The ground ring shall be buried at a depth below the earth’s surface of not less than 750 mm (30 in.).

(C) Connections to Ground Rings. Where the grounding electrode conductor is connected to a ground ring as permitted in 250.52(A)(4), that portion of the conductor that is the sole connection to the grounding electrode shall not be required to be larger than the conductor used for the ground ring.

While only required to be not smaller than 2AWG, we typically run 3/0 or 4/0 in non-residential scenarios.

 

[TMMB]

Thank you Smart

is that mean there is no calculation to obtain the ring conductor size?

 

[Smart $]

Thank you Smart

is that mean there is no calculation to obtain the ring conductor size?

That is correct!

 

[hurk27]

I want to point out that you mentioned a grounding grid which is used to eliminate step potential that many times a ground ring can not do, I just wanted to point out that there is a difference?

A grounding grid is an equal potential system that prevents voltage gradients in the area of protection.

But that you made the statement "Around the building" sounds like you are talking about a ground rings?

 

[petersonra]

I HAVE A BUILDING 35X19 m , total connected loads : 650KVA , how can sizing the grounding grid conductor (around the building), VOLTAGE SYSTEM IS 380V, 3PHASE , 60HZ

PLEASE ADVICE

REGARDS

I don't think there is generally any requirement for a ground grid at all. It is a design decision.