600 AMP Service

[rbwsparky]

We will be installing a 600 amp service in the coming weeks. We want to install a 4" EMT or RMC between the current transformer and the 600 amp main panel. Would a 2/0 cu ground wire be needed in this conduit also?

 

[Cow]

Where would you hook up a ground wire at the transformer?

 

[infinity]

No, if the 600 amp panel contains the main the neutral conductor will be used for all service bonding on the line side of the main disconnect.

 

[rbwsparky]

Sorry I meant current transformer cabinet. Typing is not my strong point.

 

[augie47]

what infinity said + you need to assure bonding of all metal conduits (250.92).

 

[rbwsparky]

We considered PVC. Would that change matters?

 

[augie47]

your CT cabinet could still be bonded by your neutral.

 

[Jim W in Tampa]

We considered PVC. Would that change matters?

pvc is fine and actually easier as you wont need a meg bushing.
just bond the cabinet to neutral

 

[rbwsparky]

Would I be correct with the 2/0 cu or am I overlooking something?

 

[Jim W in Tampa]

Would I be correct with the 2/0 cu or am I overlooking something?

What are you trying to ground The cabinet is bonded to neutral.

 

[rbwsparky]

This is the first 600 amp we have done. We do residential, and 400 amp is the most common size we do. This is a 12000 sq ft home that depends on electric heat and we can't afford mistakes. I only want to do it right the first time.

 

[augie47]

I'm unsure exactly what you are connectimng with the 2/0..but assUming
(2) 350 kcmil for the 600 amp, a 2/0 would be the right size bonding condcutor on the line side of the disconnect per 250.66

 

[rbwsparky]

I need to bond CT cabinet to main panel, no?

 

[augie47]

I need to bond CT cabinet to main panel, no?

you can bond it with a 2/0 bonding jumper or you can bond it by using the neutrals as they pass thru. Often a stud kerney is used for this.

 

[rbwsparky]

Your information cleared things up. Thank you

 

[nunu161]

i dont think you will need a ct cabinet, they make a 600 amp self-contained meter

 

[infinity]

I need to bond CT cabinet to main panel, no?

If you're asking about running #2/0 conductor between the CT cabinet and the the panel the answer is no. You bond the neutral to the CT cabinet and bond it again to the panel containing the main. Installing an addition #2/0 between the CT and the panel creates a parallel path for the neutral current.

 

[augie47]

Rob, Would you have a problem if a 2/0 was installed from the main and used to bond the CT cabinet in lieu of bonding with the neutral ?
(no connection to the neutral as it passes thru the CT)

 

[infinity]

Rob, Would you have a problem if a 2/0 was installed from the main and used to bond the CT cabinet in lieu of bonding with the neutral ?
(no connection to the neutral as it passes thru the CT)

Gus do you mean that the neutral would be floating in the CT cabinet and the #2/0 from the panel would provide bonding of the CT cabinet? Around here the POCO requires that the neutral be bonded directly to the CT cabinet.

 

[augie47]

yes "floating neutral" I was just clarifying post #17 in my head.
The OP mentioned bonding via 2/0 from the main and I would think thiks would be acceptable (ignoring POCO rules) IF the neutral is not bonded in the CT.. correct ?