1200A service

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Btrox

Member
Location
Mpls, MN
Has anyone put in a 1200a service from a utility pole? I've put them in on commercial/Industrial buildings but not from a pole.
This job the utility is going to get me 208/120 3PH from a power line 65ft from the service. I'd be running the service wire up the pole to the MCB. It would be 4 runs of 400Kcmil w/ neutral (3" C.)
It would seem I would run down the pole with 4 runs of PVC, (neutral), go underground all the way to the MCB, all with goosenecks at the top: (that's a lot of geese up there.)


I've always had a pad mount XFMR on the outside and a short run with a wireway or underground into the building; not from a pole 65ft away. The building owner is too cheap to pay for the utility to dig in a pad mount XFMR. Any ideas?? thanks in advance.
 

growler

Senior Member
Location
Atlanta,GA
The building owner is too cheap to pay for the utility to dig in a pad mount XFMR. Any ideas?? thanks in advance.

When I have a problem like this I alway get a power company engineer to meet with me on site and talk about what is the best ways to get power to the site.

They have to approve what you do along with the local authorities.

After you get things settled with then engineer then you talk to the inspection department.

In some areas they will not let you bring a service overhead so it doesn't matter how cheap the owner is because they don't have any choice.

Before you quote a price make sure everyone is OK with what you are going to do. I'm not going to bite the bullet on a job like this, I'm going to know that it's going to pass before I ever start. :)
 

satcom

Senior Member
When I have a problem like this I alway get a power company engineer to meet with me on site and talk about what is the best ways to get power to the site.

They have to approve what you do along with the local authorities.

After you get things settled with then engineer then you talk to the inspection department.

In some areas they will not let you bring a service overhead so it doesn't matter how cheap the owner is because they don't have any choice.

Before you quote a price make sure everyone is OK with what you are going to do. I'm not going to bite the bullet on a job like this, I'm going to know that it's going to pass before I ever start. :)

Yup, it doesn't matter how cheap the owner is because they don't have any choice, cheap owner, is the first red flag, so get what is required first, then get the contract signed.
 
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Btrox

Member
Location
Mpls, MN
thanks for your thought, yes; I've been down that road with the utility and the owner and a service lateral is what they all decided on. Actually, it was a high leg system but the utility would add another XFRM make it a true 208/120v Y system. It's a 65ft dig from there and just looking for other ideas rather than 4 conduits up the pole to feed the service but that's probably the only way.

My preferance was a pad mount XFRM just outside the building; but they would need to trench in the primary over 300ft. BIG BUCKS$$$$

thanks again.
 

growler

Senior Member
Location
Atlanta,GA
This job the utility is going to get me 208/120 3PH from a power line 65ft f It would be 4 runs of 400Kcmil w/ neutral (3" C.)
The building owner is too cheap to pay for the utility to dig in a pad mount .

Curious, why can't they just get the primary from the pole 65' away?


That is the $64 question. Why is it going to be cheaper for an EC to run 4 runs on the secondary than for the power company to run one run on the primary.

Unless Btrox has already given them a price and is locked in by contract. This sounds kind of expensive for the customer if he pays an EC to do it. :-? I know it's going to get expensive if they want me to do it.
 

KWH

Senior Member
Conduits up pole

Conduits up pole

The POCO might be able to set a termination box @ the base of pole eliminating all of your risers up the pole. The power company would supply all primary wiring from cans to the box, we recently completed 2 jobs setup this way but they were 800amp services. The POCO supplied everything including the box.
 

kwired

Electron manager
Location
NE Nebraska
Is your 1200 amps oversized for the actual load or it is close to fully loaded?

Those would have to be some pretty large transformers to hang on a pole if they are sized to carry 1200 amps, even taking into consideration that most POCO's do not size transformers much heavier than absolutely needed and will consider overloading them to some extent.

If a POCO is going to charge for required construction on their part, they will still have large transformers and fairly hefty pole or even multiple poles to support this unless the actual load is not very high.

Most POCO's I work around if over 150 kVa transformer is needed or 75 kVa single phase you have no choice but pad mounted transformer.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
I did a 1200 amp single phase overhead service years ago, the utility knew it was a 1200 amp service, but they underestimated the load, less than a month after we fired it up they were blowing fuses, their fix to the problem: put in bigger fuses........ then after the transformer caught on fire, they decided they better put in a bigger transformer! It is massive, three of them would probably break the pole over! The poco here can put in an underground feed way cheaper than I could do it, $200 for up to 200' for a single phase 200 amp service.
 

hardworkingstiff

Senior Member
Location
Wilmington, NC
I did a 1200 amp single phase overhead service years ago, the utility knew it was a 1200 amp service, but they underestimated the load, less than a month after we fired it up they were blowing fuses, their fix to the problem: put in bigger fuses........ then after the transformer caught on fire, they decided they better put in a bigger transformer! It is massive, three of them would probably break the pole over! The poco here can put in an underground feed way cheaper than I could do it, $200 for up to 200' for a single phase 200 amp service.

I did a service change last year that PoCo fed the CT cabinet with 350 AL and I fed from the CT cabinet to the panel with 3 sets of 400 CU. PoCo is coming out of a 100 KVA single-phase transformer and feeding this service, a 400-amp service for a dock and a 200-amp service for a building (all with separate service laterals from the transformer). As the summer heats up, it will be interesting to see what happens.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
The original service was 400 amp with 380 amps worth of load, the poco feed it with a 4/0 AL triplex underground, voltage at service was 102 volts at full load during the summer. The new service was overhead, and the engineers wanted to run (2) 4/0 triplexes. The load was being increased to 750 amps. Met with the engineers and was able to get them to upgrade to (2) parraleled 350 kcmil quadraplex's After they finally changed to the bigger transformer, the customer had no more voltage issues.
 

iwire

Moderator
Staff member
Location
Massachusetts
When I have a problem like this I always get a power company engineer to meet with me on site and talk about what is the best ways to get power to the site.

Can't argue with that. If you do it as Growler suggests you will only price and build the service once.

I had a job where the GC refused to wait for the power company engineers, had me build a 400 amp 208Y/120 service where an existing 200 amp single phase service was.

When the power company finally did show up they just laughed and gave us some options, wait months to get power to the mast I installed or relocate the service 125' to the other side of the building and get power in a day.

The GC had to pay us a large amount of money to us to relocate the service. :grin:
 

mivey

Senior Member
Most POCO's I work around if over 150 kVa transformer is needed or 75 kVa single phase you have no choice but pad mounted transformer.
That's pretty small. We usually draw the line at a bank of 250's.

I suspect this service would get a bank of 100's. If they know the service is really maxed for long periods then they might get a bank of 167's.
 

mivey

Senior Member
Can't argue with that. If you do it as Growler suggests you will only price and build the service once.

I had a job where the GC refused to wait for the power company engineers, had me build a 400 amp 208Y/120 service where an existing 200 amp single phase service was.

When the power company finally did show up they just laughed and gave us some options, wait months to get power to the mast I installed or relocate the service 125' to the other side of the building and get power in a day.

The GC had to pay us a large amount of money to us to relocate the service. :grin:
I recommend you consult with every service drop, even residential. The POCO may have plans to remove that transformer you have your eye on.
 

Btrox

Member
Location
Mpls, MN
reply

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thanks for all the responses, the primary would cost over $30k for the utility to run, (not that my price is cheap). I may have to look into the termination box on the pole and see if the POCO would put that in.
thanks again.
 

kwired

Electron manager
Location
NE Nebraska
thanks for all the responses, the primary would cost over $30k for the utility to run, (not that my price is cheap). I may have to look into the termination box on the pole and see if the POCO would put that in.
thanks again.

If you have the need for 1200 amp service this facility certainly should have an investment not only in switchgear, panelboards, and other premisis wiring but also the equipment that it powers plus the value of products or services offered. 30,000 investment to power it up is probably not that large of a number considering what you are getting for your money and is probably much less than other energy sources would be. If they bought enough diesel engines and generators plus necessary equipment to make them work they would spend much more. Plus would cost a lot more to operate than they can buy utility power for.

Owners are not seeing this as a necessary investment. How much does POCO want for the currently proposed setup? Or is it something existing and that is why it looks cheap. If it is existing is it large enough to handle the load or are they just going to take a chance that it will work and have trouble at the time they find out it is not large enough and spend most of the 30,000 at that time to upgrade it and eat whatever the down time ends up costing?

How much is POCO going to charge if they put the termination box at base of pole? May look better than 4 raceways running up the pole but may cost about the same or even more after all is done.
 
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