Voltage Drop

[Fordean]

Have 3 airport hangers. 1675 feet from main road, to the Existing Overhead poles.

Would it be ok to run Underground 750mcm

Would require 2 manhole I guess @ 550, and 1100 feet. 120/208volts. 3 phase. Hangers don't use much.

They asking for about 3 - 20 amps circuits per bay ( 12 bays per building, 3 buildings) 300 long by 50 wide, 20 feet high.

1ckt for 2 - 150 watt HID lights
1ckt for 1hp Bifold door.
1 ckt for GFI general use

Each building would get 7- 400 watt MH wallpacks.

Plan on feeding the 3 buildings. ( 1 - 150 amp MB panel 1 phase) per building.

Service from street. Will be 3 phase 400 amps. But the Load calc will definitely can diversify, Due to only a fraction of use in the hangers. What diversify % I would have to estimate.

From the 400 amp Service to Each 150 amp 1phase MB panel - Run 2/0 about 200 feet each


Then from 150 amp 1 phase panels to the (12) Small subpanels per blg. Fused @ 40 longest being 300 ft to last bay.

Was calculatings voltage drop from street to farthese panel.


(1675FT) -From over head poles to Main Blg service ( #750 MCM) 400 amp-3phase -120/208 #2/0 -150 1 phase panel( 200 FT) , + 150 mb panel 1 phase to farthest Panel #6 (300ft)

 

[bob]

1675 ft is a long way and big wire. I would compare the cost for 3 primary cables and pad mt transformer. You would have the
option to direct bury the cables and omit the man hole construction.

 

[ramsy]

What is commonly lost on this forum, if utility can't do for free, is subcontracting lineman crews to run overhead lines on power poles.

1700ft of #8 12kv distribution lines in open air, with a pole mounted, 208v secondary transformer, & overhead drop to each structure.

The lineman trucks have a big cork screw on the back, used to set the poles. All you would need is a service riser & wire for them to tie into.

 

[bob]

Bein

Bein

Ramsy, an OH line is an option. The OP mentioned airport hangers. An OH line near an airport might be a problem
due to conflict with the air space. it could be done with 6 poles +/- and 3 transformers.

 

[ptonsparky]

Have the POCO supply 480 and use transformers at buildings as needed if they will not provide underground primary to their pad mount transformers at each building.

 

[Fordean]

What is commonly lost on this forum, if utility can't do for free, is subcontracting lineman crews to run overhead lines on power poles.

1700ft of #8 12kv distribution lines in open air, with a pole mounted, 208v secondary transformer, & overhead drop to each structure.

The lineman trucks have a big cork screw on the back, used to set the poles. All you would need is a service riser & wire for them to tie into.

Specs State all site wiring underground. I really want to just run a empty conduit for the Utility to run their 13,400v to a trans. But This will cost a lot to I believe. And they wont even talk about it to find out what they do, don't do, Charge or whatever. Very difficult to determine a number for the Incoming when your dealing with utility. 1 day the charge nothing. Next day they want 40,000.00

 

[ramsy]

Sometimes property owners get much better results from utilities.
Invite the property owner to reach out to utility for high voltage feeder cost to their own structures.

You can quote inside / outside separately if utility lets you.
Perhaps reach out to a local IBEW lineman contractor, to quote & sub the outside / high voltage. They also have more experience dealing with the POCO.

 

[kingpb]

Specs State all site wiring underground. I really want to just run a empty conduit for the Utility to run their 13,400v to a trans. But This will cost a lot to I believe. And they wont even talk about it to find out what they do, don't do, Charge or whatever. Very difficult to determine a number for the Incoming when your dealing with utility. 1 day the charge nothing. Next day they want 40,000.00

You have to get a hold of the local utility service rep for that area, set an appointment at the site, and make sure you are not late. Go over what you need with him on the spot. He will be able to give you a good idea on what they will/won't do and then follow up with what the costs might be. Owner will probably have to be involved for payment coordination.

 

[Fordean]

You have to get a hold of the local utility service rep for that area, set an appointment at the site, and make sure you are not late. Go over what you need with him on the spot. He will be able to give you a good idea on what they will/won't do and then follow up with what the costs might be. Owner will probably have to be involved for payment coordination.

I have decided to Bring the 13,200 to within the 35 feet of buildings. Its the only thing that makes sense. But putting the Cost in on state work is impossible. So I excluded it. As the Utility don't even discuss the designs or pricing until you file a
WO order. In which I am not doing if I don't have project yet.

 

[Tony S]

The cost of MV supplies in the US is surprising low to what I’m used to.

£70K ($105K) for a 200Ft run with switchgear (no transformer). The DNO (PoCo) required a building to their specifications.
We had the 800KVA transformer it needed supplying from a new source. The total job ran to £130K ($192K) with both our and the DNO requirements added in.