The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Industrail Control Panel bonding per 409.108
by sparkyinak
Today at 06:29 PM
Calling all Non-US members!! (Non-US only)
by aussie240
12/07/16 02:39 AM
Photo Upload Tutorial
by DanK
12/06/16 11:35 PM
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
On Delay Relay with Auto Reset
by Potseal
12/01/16 09:59 AM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 13
HotLine1 10
sparkyinak 9
Texas_Ranger 8
Potseal 6
Who's Online
2 registered (sparkyinak, LongRunner), 90 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#87349 - 02/18/04 06:04 AM Voltage drop 4160
Yoopersup Offline
Member

Registered: 03/04/03
Posts: 826
Loc: Michigan
Question
formula for voltage drop
example 4160 mtr. distance 475 ft. full load amp (500hp) 70 . Copper wire.
22.3x distance x amps divided circular mil of cooper wire.
22.3x475x70=741477
#4=41740area cir. mills
741477divided by 41740=17.76 voltage drop
4160x3%=124.8
hows it look guys????

Top
2014 / 2011 NEC & Related Books and Study Guides
#87350 - 02/18/04 01:16 PM Re: Voltage drop 4160
earlydean Offline
Member

Registered: 12/22/03
Posts: 749
Loc: Griswold, CT, USA
I prefer the formula VD = 1.73xLxIxR/1,000. The R is resistance per 1,000 feet from Table 9 of Chapter 9. L is the distance from the source to the load in feet. Note that the impedance varies with the pipe type. But is not significant except with higher ampacities. For your parameters using PVC conduit I get: VD = 1.73x475x70x0.31/1,000 = 17.83 volts. Pretty close.
Use 2 instead of 1.73 for single phase.

Earl
_________________________
Earl

Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals