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
Forum Software Upgrade coming soon...
by Ruben Rocha
9 minutes 41 seconds ago
ESA Arc flash course
by frank
38 minutes 45 seconds ago
Re: Fabricating Guards out of Lexan?
by frank
Yesterday at 04:11 PM
Would ELV branch circuits be a good idea?
by gfretwell
Yesterday at 01:26 PM
Why cables look like they do
by Texas_Ranger
Yesterday at 12:33 PM
New in the Gallery:
Desk-mounted "power-board"
Top Posters (30 Days)
HotLine1 21
Webmaster 20
Trumpy 12
ghost307 12
frank 12
Who's Online
3 registered (Webmaster, Ruben Rocha, sparkyinak), 0 Guests and 197 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#90710 - 12/08/04 08:17 AM Fire pump feeder & disconnect
Yoopersup Offline
Member

Registered: 03/04/03
Posts: 826
Loc: Michigan
Fire pump 20hp & booster pump 3/4 hp.460volt3phase

20hp=27amps LRC=145 amps
3/4 hp=1.6 amps LRC 12.5 amps
Disconnect Size 145 +12.5=157.5
240.6 next size up 175amps
175amp disconnect switch
The way I read it from the fire pump locked rotor sized disconnect switch to fire pump controller wire sized at 125 %
27plus 1.6=28.6x125%=28.6
according to the code 175 amp disconnect switch with 30 amp wire from switch to fire pump controller then to the mtr. code handbook 2002 pages 975-976.
Please comment . Thank u

Top
2017 / 2014 NEC & Related Books and Study Guides
#90711 - 12/08/04 04:30 PM Re: Fire pump feeder & disconnect
George Little Offline
Member

Registered: 01/18/04
Posts: 1492
Loc: Michigan USA
Yooper- I see you got it right. You must have had a good teacher
_________________________
George Little

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