i am going to be building a house 380' off the road. Local power company wants to bring underground service in 200' to meter, other 180' is my problem. Plan is to set meter channel and 200amp outdoor panel with feed through lugs. I am getting conflicting reports as to what size wire would be adequate to run the 180' without maxing out voltage drop. Supply house says 4/0 AL is plenty, electrician says 350 wire. House is 1800 sqft., forced air propane/wood, gas cooktop, electric double oven (50amp), propane hot water, central A/C. Also want to run 100 amp to barn/shop from house. Thanks in advance.
200 amp service
- Thread starter sfd524
- Start date
pattenp
Well-known member
I'll add to the confusion by saying #250 Al.
pattenp
Well-known member
#4/0 is .528 in and #250 is .575 in. #250 is the next size up from #4/0. The 200A lugs should be marked for a size range, most likely #250 will fit.
lakee911
Well-known member
Probably ought to back up a bit ... what does your load calc say the house will need for amperage? See http://www.mikeholt.com/documents/calculations/formulas/ResidentialLoadCalculations.xls if you've not done one yet.
Is the power company setting a transformer, or is that back on the pole? If it's back on the pole what is so special about the 200' demarcation point that they have given?
Is the power company setting a transformer, or is that back on the pole? If it's back on the pole what is so special about the 200' demarcation point that they have given?
Lake, the 200' was set by the power company, no transformer on property. I convinced the engineer to come out to the property on monday to review with me what his plan is. I originally thought they would set a transformer around the 325' mark but he said no over the phone. That's when he came up with the plan above.
lakee911
Well-known member
That's probably best. Certainly let us know what he says.
Typically the utility runs much smaller wire to the meter (because they can for one, and because they can push things to their limit, they count on diversity factor, etc) which causes additional VD. They can also adjust transformer taps to account for the VD too. On their end it's no big deal.
If it's after your meter, on your end, you pay for the VD (as heat from the resistance).
I would probably use 100A for your VD calcs knowing that it could be more or it could be less. My spreadsheet, with 3% VD (what I try to design to) calls for 1/0 Alum. at 240VAC single phase--says its good for 183 feet. Remember this is to meet the VD requirement, not what the code says you need to use.
wyliesdiesels
Well-known member
I would figure out what your service size is going to be before you spend time trying to figure out what size wire to use.
wyliesdiesels
Well-known member
I guess what I should've said is first figure out what your total calculated load is going to be including house and garage. I know u said 100a min was what u came up with for the house but what are u gonna have in your garage- welder, compressor, wood working machines, etc. Also, will it just be you working in there or will there be others @ the same time? If you don't have anything too major then yeah I would just go with 200amp total service so u have some headroom for the future in case u change your mind down the road and want to add some heavy machinery!
Total calculated load for house said 100 amp minimum. I can't get to calculator on my "smart" phone, says its password protected, will try tomorrow when I get home. Shop is going to be just me working on farming stuff, minor vehicle maintenance. Planning on a 220 90gal. compressor, 220 mig welder (only draws < 20amps), some 15amp wood saws, high bay lighting (12- 400watt mercury lamps). Line engineer mentioned going to a 320amp service on phone then said 200 should do it. I am hoping to get more clarification when I meet with him Monday at the property. Thank you for the help here. I am trying to balance future needs with cost, with emphasis on having enough juice verses cheaping out.
wyliesdiesels
Well-known member
I think you'll be fine with 200a for your house and garage!
So for 200a @ 180' w/ recommended 3% voltage drop :
2/0 CU
250kcmil AL
If u go with 320a service, the wire is gonna cost u an arm and a leg! O_O I don't think you'll need that size service!
The formula for calculating correct conductor after Vd is:
Cm = (2K*L*I)/Vd
Cm= circular mil
K=12.9 for CU 21.2 for AL
L=length of wire
I= Amps in conductor
Vd= voltage drop (7.2 for 3%)
Input the #s and then you correspond the answer with a list of the circular mils of conductors!
So for 200a @ 180' w/ recommended 3% voltage drop :
2/0 CU
250kcmil AL
If u go with 320a service, the wire is gonna cost u an arm and a leg! O_O I don't think you'll need that size service!
The formula for calculating correct conductor after Vd is:
Cm = (2K*L*I)/Vd
Cm= circular mil
K=12.9 for CU 21.2 for AL
L=length of wire
I= Amps in conductor
Vd= voltage drop (7.2 for 3%)
Input the #s and then you correspond the answer with a list of the circular mils of conductors!
Ok, so I got to the property today. I staked out the house, pole barn and 2 possible meter sites. Then I used my measuring wheel to walk the wire routes to figure out actual wire lengths needed. This is what I came up with.
Plan A - From the road to first meter stake, as proposed by line engineer on the phone, 200 ft. From there to 200amp house panel, 210' of wire. From house panel to 100amp barn panel, 100'.
Plan B - From the road, as proposed by me, 320' to meter stake. From there, 90' to 200amp house panel. Then again, 100' to 100amp barn panel. With this plan, I would have the option to run 100amp barn panel separate from outdoor panel at meter, which would be 140' of wire.
So my question is, should I push for Plan B or will Plan A be adequate? Also going to push for underground service to meter; everything beyond meter will be underground regardless of which plan.
Thanks for all your help. Will let you know how meeting with line engineer goes.
Plan A - From the road to first meter stake, as proposed by line engineer on the phone, 200 ft. From there to 200amp house panel, 210' of wire. From house panel to 100amp barn panel, 100'.
Plan B - From the road, as proposed by me, 320' to meter stake. From there, 90' to 200amp house panel. Then again, 100' to 100amp barn panel. With this plan, I would have the option to run 100amp barn panel separate from outdoor panel at meter, which would be 140' of wire.
So my question is, should I push for Plan B or will Plan A be adequate? Also going to push for underground service to meter; everything beyond meter will be underground regardless of which plan.
Thanks for all your help. Will let you know how meeting with line engineer goes.
wyliesdiesels
Well-known member
As far as your question goes, the answer is all in the math. The decision to go with one plan or the other will largely depend on the cost difference. And the power company may charge u more for the plan that puts the meter closer to ur house. You should ask them what the cost will be for each option! I will crunch the #s for u tomorrow!
lakee911
Well-known member
Bummer.
Yep. 2 1/2 hour drive each way. Did get a couple small things done out there though.
wyliesdiesels
Well-known member
EDIT: I'm really tired tonight and I wasn't paying attention earlier! So I edited my post!
I got an email that you had posted a comment earlier but now i dont see it. Anyways, i crunched the #s too and came up with the same 247,*** cir mils result. So 250Kcmils AL will work because its just slightly larger! What u could do so u don't have to run such large wire is try to get the PoCo to get the meter closer to your house. This way u could save on wire, conduit and labor costs! Of course, the PoCo may charge u more!
I got an email that you had posted a comment earlier but now i dont see it. Anyways, i crunched the #s too and came up with the same 247,*** cir mils result. So 250Kcmils AL will work because its just slightly larger! What u could do so u don't have to run such large wire is try to get the PoCo to get the meter closer to your house. This way u could save on wire, conduit and labor costs! Of course, the PoCo may charge u more!
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wyliesdiesels
Well-known member
I wasn't paying attention earlier and I edited my previous post! Yes, 250Kcmils will work cause 250Kcmils= 250,000 cir. mils. Duh!!
I guess I shouldn't be talking about electrical while I'm a zombie!
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Met with line engineer today, she is pushing to run primary URD 320', set transformer, then connect to meter pedestal, all for $8k. Oh yeah, that does not include the primary URD or the precast concrete transformer vault, digging trench, conduit, or meter pedestal. All that is on top of the $8k. Only other option is to put meter at road and run 400' to house service panel with oversized wire, yikes. I was quite surprised to find that price did not include the wire. Last thing she said was to consider 400A(320) service.
wyliesdiesels
Well-known member
Can u say ouuucchHh! The wire alone, either way, will make your wallet spontaneously combust. Did she give u a price for the primary URD?
Nope, did't even tell me where I can find it. She did give me a list of approved manufacturers. I spoke with a friend that used to do electrical and he is guessing the total job will be around 14-16k. He thinks we can set the meter at road and over size to the house site.
wyliesdiesels
Well-known member
If it were me, I would want the meter closer to the house. But that's just my preference!
We decided to go ahead and run primary URD back to a transformer then secondary to a meter pedestal with 200A outdoor feedthrough panel for a disconnect, meter and outdoor panel will be 80' from house. I went ahead and order enough 15kv URD #2awgAL with full neutral today. Had to get two lengths as it is a DELTA system so two cables are needed. Did find a supply house that had it fo 2.07/ft.
Thanks for all the help guys.
Thanks for all the help guys.
wyliesdiesels
Well-known member
2 cables are needed for a single phase transformer regardless of the system. I'm curious about the neutral part of your primary cable as I thought Delta primaries don't have neutrals. I have seen single phase cans wired phase and neutral on the primary side but this was on a 4-wire wye primary system. The primary neutral was tied to one primary bushing and the center tapped secondary bushing on the can and then to the #6 ground @ the pole!
The neutral is around the insulation of the #2AL and under the outer jacket. Not sure about wether a Delta primary is supposed to have neutrals or not, just know that is the wire that is approved by the power company. I will still have to install a continuous #2 bare copper ground around the transformer base with 5/8x8 ground rod. I wonder if they will make me put in a ground loop for the outdoor panel as well.
wyliesdiesels
Well-known member
How much was it?
Here's the plan:
1-Set two poles, one mid span on their existing line other side of the road and the other along roadside on our property
2-Run primary underground cable to a transformer 320' off the road. Cable length will be longer due to route it takes and going up pole.
3-Set 25kv transformer on ground vault
4-Run secondary line to nearby 200A meter then outdoor 200A feedthrough panel with room for 8 additional circuits. from there to house once built.
All this for around $6900, but wait there's more.....
Power company supplies and install two poles, overhead wires to cross street, and 25kv transformer, makes all connections.
Power company does NOT supply or install trench, primary underground cable, conduit, transformer base, meter pedestal, meter cabinet, or outdoor feedthrough panel. Everything beyond the meter is all our responsibility, which is normal. That's right folks all that is on top of the $6900, plus I have to install it all. I knew that there was going to be a hefty bill to get this done right. I was surprised when the line engineer said they don't run the underground cable, only make the connections.
I was able to find a supply house for the primary URD, 15KV #2AL 220 insulation full concentric neutral. $2100
Fiberglass transformer base - $500
Conduit - $1000
Meter can, outdoor panel, misc. - $700
Excavator for one day - $500
Total Approx - $12000
1-Set two poles, one mid span on their existing line other side of the road and the other along roadside on our property
2-Run primary underground cable to a transformer 320' off the road. Cable length will be longer due to route it takes and going up pole.
3-Set 25kv transformer on ground vault
4-Run secondary line to nearby 200A meter then outdoor 200A feedthrough panel with room for 8 additional circuits. from there to house once built.
All this for around $6900, but wait there's more.....
Power company supplies and install two poles, overhead wires to cross street, and 25kv transformer, makes all connections.
Power company does NOT supply or install trench, primary underground cable, conduit, transformer base, meter pedestal, meter cabinet, or outdoor feedthrough panel. Everything beyond the meter is all our responsibility, which is normal. That's right folks all that is on top of the $6900, plus I have to install it all. I knew that there was going to be a hefty bill to get this done right. I was surprised when the line engineer said they don't run the underground cable, only make the connections.
I was able to find a supply house for the primary URD, 15KV #2AL 220 insulation full concentric neutral. $2100
Fiberglass transformer base - $500
Conduit - $1000
Meter can, outdoor panel, misc. - $700
Excavator for one day - $500
Total Approx - $12000
wyliesdiesels
Well-known member
! Oouuccch!What's your calculated continuous load and what electric appliances/machines do u have? That 25Kva trany will do just over 100a so if u have a big load, it might be on the small side....
jomobco
Well-known member
I've got 200 at my house and 200 at my shop. 50 from the house run to a barn. I would do 400 amp (probably what the transformer can carry if it's like mine) if I were doing it. In my shop you might have a 30 amp 220 compressor, 30 amp 220 welder, lights, electric heat? Water heater? Lift?
It would **** if you come up short. Not that you need everything at once but I would look at the cost difference between 200 and 400.
John,
I have been contemplating going to a 400 amp service. The power company said there is no difference in their cost. I would have to get larger secondary wire to run from transformer vault to meter can. I would also need to get the larger meter can/cabinet, which is not in the power companies estimate either way.
My thinking is that I only want to do this once. I don't know enough about calculated loads/continuos loads to tell the difference, just sure that I am only doing this once. I certainly want it to be plenty of juice for whatever may come. Local electrician thinks I will be ok with the 200 service, I don't want to be short though. As much as this is going to cost a little extra now is money well spent when compared to wanting to redo it down the road.
Wylie,
what do you think?
I have been contemplating going to a 400 amp service. The power company said there is no difference in their cost. I would have to get larger secondary wire to run from transformer vault to meter can. I would also need to get the larger meter can/cabinet, which is not in the power companies estimate either way.
My thinking is that I only want to do this once. I don't know enough about calculated loads/continuos loads to tell the difference, just sure that I am only doing this once. I certainly want it to be plenty of juice for whatever may come. Local electrician thinks I will be ok with the 200 service, I don't want to be short though. As much as this is going to cost a little extra now is money well spent when compared to wanting to redo it down the road.
Wylie,
what do you think?
Charles (in GA)
Well-known member
In a shop you need to consider what you can draw in the way of power, simultaneously.
Lights are a given but unless the building is very large, you simply won't use that much current. I suspect I am a rare exception, I have a 60x60 building and if all the lights are turned on, I am drawing 56 amps at 120 volts (6,720 watts) of lights. Thats pretty unusual, I try to not turn everything on if I can help it.
Air compressor, very intermittent and the only time it would be used in conjunction with other high draw items were if you had a plasma cutter. I don't have a plasma cutter, but I do have a 7.5 hp compressor that has a data plate amps of 33.
Welders are the other "high draw" item but truthfully, unless you are welding heavy steel and have the amps turned way up, you are not using a whole bunch of current.
Nothing else compares. I have a drill press (1 hp) some hand held power tools, the usually battery chargers for cars and for cordless stuff, but none of this draws any real amount of current. Unless you had several people all working on various projects at one time in a shop, the average GJ member is hard pressed to draw enough amperage to tax a 100 amp service or feeder.
Charles
Lights are a given but unless the building is very large, you simply won't use that much current. I suspect I am a rare exception, I have a 60x60 building and if all the lights are turned on, I am drawing 56 amps at 120 volts (6,720 watts) of lights. Thats pretty unusual, I try to not turn everything on if I can help it.
Air compressor, very intermittent and the only time it would be used in conjunction with other high draw items were if you had a plasma cutter. I don't have a plasma cutter, but I do have a 7.5 hp compressor that has a data plate amps of 33.
Welders are the other "high draw" item but truthfully, unless you are welding heavy steel and have the amps turned way up, you are not using a whole bunch of current.
Nothing else compares. I have a drill press (1 hp) some hand held power tools, the usually battery chargers for cars and for cordless stuff, but none of this draws any real amount of current. Unless you had several people all working on various projects at one time in a shop, the average GJ member is hard pressed to draw enough amperage to tax a 100 amp service or feeder.
Charles
The shop is going to be 50x40x16. Lighting is 12- 400w mercury high bay lighting (bought for $10/fixture, with two extra cases of bulbs). 5hp compresser (220v-28amps?), Mig welder (220v-20amp draw), plans for a hyertherm45 plasma cutter, miscellaneous power saws/drills/grinders (max 15amp each), radio, exterior LED flood lighting, circulator pump for heating, OHD openers, beer fridge.
I think the 200amp main service with a 100amp subpanel should be enough, but again I am just guessing. Truth be told, a little nervous about spending this kind of money and getting it wrong or regretting it later.
Any and all input is graciously accepted!
Lee
I think the 200amp main service with a 100amp subpanel should be enough, but again I am just guessing. Truth be told, a little nervous about spending this kind of money and getting it wrong or regretting it later.
Any and all input is graciously accepted!
Lee
What kind of compressor is this 220v 90 gal?