Two panels

[John Wayne]

Customer has an existing 200 amp panel. We will be adding a second 200 amp panel next to it. There is a number 4 copper going to the water main and a number 6 going to the ground rod. I believe all I need to do for the second panel is to connect the two panels with a number 4. Am I correct? Thanks in advance

 

[infinity]

Is there an OCPd ahead of the second panel? If so you only need an EGC run with the second panel feeder.

 

[LarryFine]

Sorry, Duke, but you're incorrect. You can either run a new conductor of each, or one sized for the entire new total service conductor size.

What is the new panel for?

 

[John Wayne]

Sorry, Duke, but you're incorrect. You can either run a new conductor of each, or one sized for the entire new total service conductor size.

What is the new panel for?

Adding a second 200 amp panel because they are building an addition

 

[John Wayne]

Adding a second 200 amp panel because they are building an addition

No overcurrent protection before panel

 

[tom baker]

Is the size of the service entrance conductors changing?

 

[John Wayne]

The first panel will remain the same (200 amp 4/0) and the second panel will be the same

 

[suemarkp]

Are you installing a 320A meter socket (or is the existing one greater than 200A)? Are you doing a load calc to prove you won't be overloading the service drop, meter, or service entrance conductors? How (where) are you splicing the service to feed 2 panels?

 

[LarryFine]

If you'll have only a meter and two main-breaker panels (and you're not allowed to land GECs in the meter), your best bet is a second set of #4 and #6 GECs .

 

[infinity]

The question is how are you connecting the second panel?

 

[John Wayne]

The question is how are you connecting the second panel?

Thanks guys - Larry I will just run their own sets

 

[powerpete69]

We are assuming your are feeding the second panel with a 200 amp branch double pole breaker from the first panel?
If so, then run 4/0 wire to second panel with a #6 ground. Separate the neutral and ground bus in the additional panel. Your second panel can be main lug only or you can add a 200 amp main breaker for convenience to the second panel.

You can wire off of the main lugs of the first panel with 4/0 and #6 ground to the second panel as long as you are within 10 feet and have a 200 amp main breaker on the additional panel.

 

[LarryFine]

We are assuming your are feeding the second panel with a 200 amp branch double pole breaker from the first panel?

I'm not; I take it to include a replacement meter with double lugs.

 

[infinity]

We are assuming your are feeding the second panel with a 200 amp branch double pole breaker from the first panel?
If so, then run 4/0 wire to second panel with a #6 ground. Separate the neutral and ground bus in the additional panel. Your second panel can be main lug only or you can add a 200 amp main breaker for convenience to the second panel.

You can wire off of the main lugs of the first panel with 4/0 and #6 ground to the second panel as long as you are within 10 feet and have a 200 amp main breaker on the additional panel.

Pete can you explain this further? Are you referring to the lugs on the line side of the service disconnect in the first panel?

 

[powerpete69]

Pete can you explain this further? Are you referring to the lugs on the line side of the service disconnect in the first panel?

Referring to the lugs on the line side of the 200 amp main breaker of the first panel in regards to current carrying wires (or I guess you could say the lugs on the load side of the meter). That being said, if the line side of that breaker is fed with a 4/0 wire, then the 10 tap foot rule will not be needed if you continue to feed with 4/0. You could run any distance past those lugs if I interpreting what is going on correctly, I may not be.

After further reading, sounds like he is just asking about ground wire. Per code , looks like #4 will work (250.66) to the second panel terminated from the ground bar in the first panel.

And now that I think about it more this second panel would also be service rated (not a sub panel) so I would think you would combine the ground and neutral in this second panel?

 

[John Wayne]

Referring to the lugs on the line side of the 200 amp main breaker of the first panel in regards to current carrying wires (or I guess you could say the lugs on the load side of the meter). That being said, if the line side of that breaker is fed with a 4/0 wire, then the 10 tap foot rule will not be needed if you continue to feed with 4/0. You could run any distance past those lugs if I interpreting what is going on correctly, I may not be.

After further reading, sounds like he is just asking about ground wire. Per code , looks like #4 will work (250.66) to the second panel terminated from the ground bar in the first panel.

And now that I think about it more this second panel would also be service rated (not a sub panel) so I would think you would combine the ground and neutral in this second panel?

 

[John Wayne]

We will have one meter and two main breaker panels side by side .We don’t land the GECs in the meter ( Like Larry said above). I talked to the inspector today and he said I needed a 4 to the water main , a 4 to the ground rod , and a 4 to connect the two panels.

 

[LarryFine]

I talked to the inspector today and he said I needed a 4 to the water main , a 4 to the ground rod , and a 4 to connect the two panels.

He's correct on the first one, the second only need be #6 cu, and the third is not required at all.

The two sets of GECs already (and unavoidably) already interconnect the two panels' neutrals.

 

[mopowr steve]

He's correct on the first one, the second only need be #6 cu, and the third is not required at all.

The two sets of GECs already (and unavoidably) already interconnect the two panels' neutrals.

His inspector probably ,like many; consider the GEC to the rod as being subject to physical damage so they resort to the allowance of using #4 instead of the #6.

 

[LarryFine]

His inspector probably ,like many; consider the GEC to the rod as being subject to physical damage so they resort to the allowance of using #4 instead of the #6.

If so, that's just a matter of wire gauge, thus just a few cents.

You certainly agree the inter-panel jumper is not required, yes?