Please Review My Project and Service Calcs

C

CCWest1

Member
Location
New York
Occupation
Electrician, Semi-Retired
Guys,
I need your help in reviewing my project and especially my service calculations. I am attaching 7 files to give you a broad view of what I'm trying to accomplish. Graphics are sometimes better than words. I have a piece of property where I will be putting 2 manufactured/mobile homes and a detached garage. Also a generator which will be for 1 home and the garage. I want to bring in two residential 200A services. My POCO is NYSEG, and I've been following their Spec Book. A bit uncertain if they will allow me to put in two services, though from what I have determined I think they'll allow it. We'll see. If there is anything you see here that needs to be changed please let me know. I am kind of scratching my head on the calcs, so let me know. Thanks!
 

Attachments

  • Survey with Improvements R4 A.pdf
    281.2 KB · Views: 9
  • Metal Garage 20 x 25 x 10 A-1 R1 X.pdf
    165.9 KB · Views: 3
  • Meter Board R2.pdf
    490.1 KB · Views: 5
  • SE TS & 40 Circuit Panel Layout pg1.pdf
    580.5 KB · Views: 6
  • SE TS & 40 Circuit Panel Layout pg2.pdf
    293.7 KB · Views: 2
  • Service Calc 200A Service #1 X.pdf
    421.5 KB · Views: 4
  • Service Calc 200A Service #2 X.pdf
    437.6 KB · Views: 7
CCWest1, please update your profile to include your occupation.
 
Site plan is such that you only have one service with two feeders for the mobile homes/barn. Contact your AHJ or EI as all this would be approved or denied by them.
Size service from POCO pole to Meter pedestal would need to be appropriate for entire site. POCO (NYSEG) would not normally provide 2 separate services onto the site.
Service pedestal would normally get a service trough and taps into each meter base and each would also have a disconnect at the pedestal.
If wire size is a concern for costs, you can run parallels, but additional considerations need to be made such as same idea of the trough and taps to the individual meters. Also if parallel installation is done the Grounded (neutral) conductor would be sized in each set of parallel as if it was the only Grounded (neutral) conductor for the to entire loads. In this case if the calculations are correct and Size for the parallel can be 4/0 your neutral would need to be a Minimum 3/0 not the normal expected minimum of a #2. (This rough calculation, to really calculate the neutral size you would use the Circular Mils of the ungrounded conductors and the chart in 250.102(C)(1). )

Review of 230.2 and 230.3 would be appropriate in this installation. (Current code cycle NYS outside of NYC is the 2017 NEC)
 
Fred B said:
Site plan is such that you only have one service with two feeders for the mobile homes/barn. Contact your AHJ or EI as all this would be approved or denied by them.
Size service from POCO pole to Meter pedestal would need to be appropriate for entire site. POCO (NYSEG) would not normally provide 2 separate services onto the site.
Service pedestal would normally get a service trough and taps into each meter base and each would also have a disconnect at the pedestal.
If wire size is a concern for costs, you can run parallels, but additional considerations need to be made such as same idea of the trough and taps to the individual meters. Also if parallel installation is done the Grounded (neutral) conductor would be sized in each set of parallel as if it was the only Grounded (neutral) conductor for the to entire loads. In this case if the calculations are correct and Size for the parallel can be 4/0 your neutral would need to be a Minimum 3/0 not the normal expected minimum of a #2. (This rough calculation, to really calculate the neutral size you would use the Circular Mils of the ungrounded conductors and the chart in 250.102(C)(1). )

Review of 230.2 and 230.3 would be appropriate in this installation. (Current code cycle NYS outside of NYC is the 2017 NEC)
Click to expand...
Thank you Fred! Great reply. and very informative. Looks like I'm back to the drawing board. Have a nice day!
 
Nice layout two comments I have
You have 32 kVA of load on a Automatic transfer Switch (ATS) to a 24 kW generator.
Since its an optional standby if you look at article 702.4 you need to either manage the load with load shed,
provide a 32kVA or larger generator,
or disable the 'automatic' part of the transfer switch and wire it to manual transfer only (toggle switch start).

Many generator dealers sell these load shed devices to meet 702.4(B)(2)(b) (just an electrically held contactor), this could be complicated by the fact your mobile home is a 100A feeder off the generator panel.


My other comment is for a mobile home you use 550.18 for the service calculations, which does allow you to use the 220.82 optional but gives you a few other options there, usually with a new mobile home or mfg home its all provided for you, perhaps that is what you posted?
 
tortuga said:
Nice layout two comments I have
You have 32 kVA of load on a Automatic transfer Switch (ATS) to a 24 kW generator.
Since its an optional standby if you look at article 702.4 you need to either manage the load with load shed,
provide a 32kVA or larger generator,
or disable the 'automatic' part of the transfer switch and wire it to manual transfer only (toggle switch start).

Many generator dealers sell these load shed devices to meet 702.4(B)(2)(b) (just an electrically held contactor), this could be complicated by the fact your mobile home is a 100A feeder off the generator panel.


My other comment is for a mobile home you use 550.18 for the service calculations, which does allow you to use the 220.82 optional but gives you a few other options there, usually with a new mobile home or mfg home its all provided for you, perhaps that is what you posted?
Click to expand...
Hey, yeah...good catch but actually now a bummer....I reworked my calculations for the mobile #2 and the garage and I'm now coming up with 29248VA total. So going with a 30 or 32KW blows my budget out of the water. I would definitely prefer an auto TS, cause if I'm not around in the middle of winter things could freeze up on me. Thinking instead of going with a 100A auto TS that is not a SE switch, and just energizing essential circuits. The problem is essential circuits would be the mobile plus a couple of baseboards and well tank in the utility room of the garage. Hmmm...

And yes, the calculations for the nameplate loads were given to me by the manufacturer of the home.
 
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