Advice Please 100AMP sub Panel Commercial garage addition.

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searlest

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Hello and thanks in advance I have Mostly industrial experience and have been ask by a good friend to help with the installation of a sub panel in a 60 X 80 attached addition on to his Diesel/semi repair facility I will outline the situation then list my questions below that. Thanks in advance

60 X 80 attached addition on to his Diesel/semi repair facility

100 AMP sub panel

He has plenty of capacity to feed the sub panel from two 200AMP distribution panels in his existing shop

Distance from two 200AMP distribution panels to new sub panel is 110 feet

the loads on the new sub panel are as follows

20) 4 foot led lights ( 5 rows of 4)

20) Duplex receptacles

2) outdoor lights

4) welder receptacles

2) exit lights

QUESTIONS

1) Is #1 copper the correct size for the feeder wires ?

2) Should the feeder wires be 4 conductors with down sizing the ground one size to a #2 ok?

3) should Ground and neutral be isolated in sub panel

4) should there be grounding rod(s) installed at sub panel? 1 or 2 ?

5) Should all 120 V receptacles be on GFCI breakers ?

6) there is only one welder in shop can we install 4 welder (50 AMP) receptacles on one circuit (will more than likely install 2 per circuit)

7) Should the welder breaker be a GFCI?

8) Can someone recommend a good choice for the Led lights ? Ceiling height 18 feet. Would also like two lights with motion detection for each entry door.

9) can someone recommend a good outdoor light to install one on each end of the building at the peak (25 to 30 ft) to really provide good lighting to detour loitering and theivery

Thanks again this is a great site !
 
#1 - #1 copper is sufficient for 100A subpanel and the length of your run, assuming no need for ambient temperature derating

#2 - yes on 4 wire not sure on #2 ground

#3 - yes

#5 - A GFCI receptacle as first device on each receptacle circuit would be less expensive than breakers

#6 - yes

#7 - 240V circuits are not required to be GFCI protected.

The 4' lights we've used in ceilings that high (20-25') in warehouses are the HO T-5s 6 bulb fixtures, like this:

http://www.homedepot.com/p/Lithonia...F6rdDC9hs22MfFd2N9yIJk496HZSqU03akaAlkS8P8HAQ

Not LED tho.


In addition to the exterior lights, you may want to go with a small security system as well; cameras to cover exits and maybe the parking lot.

Will the new shop have electric heat, AC, or a big 3 stage air compressor? 100A seems a bit on the low side unless what you listed is complete.
 
Unless you need to size for voltage drop a #3 is all that is needed for 100A

4-wire is required and yes, isolate the grounds & neutrals in the subpanel. This rule applies to all electrical installations, not just commercial, residential, etc.

Ground (EGC) size would be based on feeder breaker size so if 100A a #8 is all that is required.

You don't have to GFCI anything indoors other than the bathroom or if they have a commercial kitchen (which I doubt)

No ground rods required since the addition is attached.

If just one welder than only one circuit would be needed with as many receptacles as you want. That's figuring moving that one welder around.
 
Little Bill said:
You don't have to GFCI anything indoors other than the bathroom or if they have a commercial kitchen (which I doubt)
Click to expand...

You need to read past 210.8(B)(4);)

There is also:

(5) Sinks — where receptacles are installed within 1.8 m (6 ft) of the outside edge of the sink
(6) Indoor wet locations
(7) Locker rooms with associated showering facilities
(8) Garages, service bays, and similar areas other than vehicle exhibition halls and showrooms

I assume from thread title that at least (8) has a good chance of applying.

Add there is also GFCI requirements in 511.12 for this application.
 
I just installed fixtures from "Sun and Stars Lighting" The high-bay LED has a 16000Lumens options. Installed on 20' high ceilings spaced 20' apart and they do the job very well.
 
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