Main breaker location outside WHERE?

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Mule

Senior Member
Location
Oklahoma
Hello, been a while since I've posted.....hope all are well....Got a situation that I've not come across before...

Got a structure that WAS institutional, but now will be used as offices and a server room. Existing service is located on poco's pole and is 200a 1ph 120/240v with a 45kw gen set installed at the pole location.

Inside the structure we have a interior loadcenter that is 200a fed U/G from pole and is completely full and appears to be fairly well loaded with HVAC and lighting loads as the structure is roughfully 10-12000 sqft.

Customer wants to install a server room which will include server racks, UPS units and a additional 3ton hvac unit.

Preliminary calulations are looking like we need to enlarge the service, which will by default render the gen set too small as currently installed at the pole. Everyone is wishing that the gen set had been installed at the structure instead of at the service pole location...

Finally getting to my QUESTION here...
Can I enlarge the service on the pole (poco supplied), then install a second main (at the pole, or outside rack adjacent to pole) with U/G feeder to handle only the bulk of the hvac loads via a new installed hvac loadcenter at structure. Then leaving the existing gen set, feeder, and interior panel, and utilizing it for the new server room and new server room hvac, and other critical loads?

I guess what's not clear to me is, where does the location of the six switch rule have to be. NEC says outside, or inside nearest the point of entrance. So, WHERE is outside? out at the pole 75ft away...hopefully yes...haha...truthfully I've not run into this before...

Thanks Mule
 

Buck Parrish

Senior Member
Location
NC & IN
It's debatable but most would say the pole is a seperate structure. So you would need an other one at ther building.
The existing interior panel is coming up from under the concrete slab. Under the slab is considered outside.
The disco's have to be grouped. So on the pole for the new one sounds better to me.
If you have an AHJ in your area this might be a good time to have him meet you out their.
 

ron

Senior Member
Mule,
Often, I've found that the POCO will not provide a second service until the first one is at least 2000A. 230.2(C) or you need special permission .... from whom I'm not sure.
 

Mule

Senior Member
Location
Oklahoma
Mule,
Often, I've found that the POCO will not provide a second service until the first one is at least 2000A. 230.2(C) or you need special permission .... from whom I'm not sure.

Thanks, Just making myself clear here....Not asking about a second service....asking if we can have two mains from one service, both located on, or near the pole on a switchrack. Then having seperate feeders feeding the structure, one for the bulk of the hvac load and non critical loads., and the second feeder feeding critical loads, with existing generator backup.
 

Mule

Senior Member
Location
Oklahoma
Hello, been a while since I've posted.....hope all are well....Got a situation that I've not come across before...

Got a structure that WAS institutional, but now will be used as offices and a server room. Existing service is located on poco's pole and is 200a 1ph 120/240v with a 45kw gen set installed at the pole location.

Inside the structure we have a interior loadcenter that is 200a fed U/G from pole and is completely full and appears to be fairly well loaded with HVAC and lighting loads as the structure is roughfully 10-12000 sqft.

Customer wants to install a server room which will include server racks, UPS units and a additional 3ton hvac unit.

Preliminary calulations are looking like we need to enlarge the service, which will by default render the gen set too small as currently installed at the pole. Everyone is wishing that the gen set had been installed at the structure instead of at the service pole location...

Finally getting to my QUESTION here...
Can I enlarge the service on the pole (poco supplied), then install a second main (at the pole, or outside rack adjacent to pole) with U/G feeder to handle only the bulk of the hvac loads via a new installed hvac loadcenter at structure. Then leaving the existing gen set, feeder, and interior panel, and utilizing it for the new server room and new server room hvac, and other critical loads?

I guess what's not clear to me is, where does the location of the six switch rule have to be. NEC says outside, or inside nearest the point of entrance. So, WHERE is outside? out at the pole 75ft away...hopefully yes...haha...truthfully I've not run into this before...

Thanks Mule

Correction.......Actual sq ft lighting load is 5882 @ 3.5w/ft
Got a call into POCO in reguard to service requirements
 

Mule

Senior Member
Location
Oklahoma
It's debatable but most would say the pole is a seperate structure. So you would need an other one at ther building.
The existing interior panel is coming up from under the concrete slab. Under the slab is considered outside.
The disco's have to be grouped. So on the pole for the new one sounds better to me.
If you have an AHJ in your area this might be a good time to have him meet you out their.

Talked to the AHJ and he's in agreement with my idea, thus allowing the mains to be at the pole. Woo Hoo
 

curt swartz

Electrical Contractor - San Jose, CA
Location
San Jose, CA
Occupation
Electrical Contractor
I believe you are proposing to install 2 feeders to a single building. If that is correct you will not comply with 225.30.
 

Mule

Senior Member
Location
Oklahoma
I believe you are proposing to install 2 feeders to a single building. If that is correct you will not comply with 225.30.

Hmm...Yes...This is under part II More than one building or other structure.225.30(A) Special conditions either (2,4,or 6) should apply....shouldnt it?.The Client is Institutional, and this structure WAS used as such, but now will be used as Offices for management and doctors, and a main server hub location, hence the generator issue...... I admit guys this is a first for me.

Also 225.30 (B) Special Occupancies (2) also might apply

I've installed this sort of arrangement in Industrial plant setting from the pipe lane rack to the structure, all under engineering supervision, but this is the first commercial installation I've done of this nature..

Thanks for your comments, keep me straight...
 
Last edited:

Power Tech

Senior Member
Hmm...Yes...This is under part II More than one building or other structure.225.30(A) Special conditions either (2,4,or 6) should apply....shouldnt it?.The Client is Institutional, and this structure WAS used as such, but now will be used as Offices for management and doctors, and a main server hub location, hence the generator issue...... I admit guys this is a first for me.

Also 225.30 (B) Special Occupancies (2) also might apply

I've installed this sort of arrangement in Industrial plant setting from the pipe lane rack to the structure, all under engineering supervision, but this is the first commercial installation I've done of this nature..

Thanks for your comments, keep me straight...

So your going to install a gutter and tap 2 disconnects.

Reefeed the existing and take a new line in for the critical connected to the xfer switch?
 

Mule

Senior Member
Location
Oklahoma
So your going to install a gutter and tap 2 disconnects.

Reefeed the existing and take a new line in for the critical connected to the xfer switch?

Yes, But, Im still waiting on POCO to call me back, and if they provide the riser thus saving some of the cost, Im going to try and sell a 400amp main disc to the customer in the deal. This would kill the whole gutter and sub mains... I think having a single main would be less confusing to the would be user, in leu of the six switch rule in this case...Just my 2cents
 

Mule

Senior Member
Location
Oklahoma
Yes, But, Im still waiting on POCO to call me back, and if they provide the riser thus saving some of the cost, Im going to try and sell a 400amp main disc to the customer in the deal. This would kill the whole gutter and sub mains... I think having a single main would be less confusing to the would be user, in leu of the six switch rule in this case...Just my 2cents

POCO will install a 400 direct meter loop with main. Customer only pays for the breaker $350.....pretty good deal
 
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