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

   
Topic Options
Rate This Topic
#129516 - 04/05/05 04:28 PM motor disconnect question
knopp Offline
Junior Member
Registered: 06/26/04
Posts: 2
Loc: richmond, va
i have two 480 3 phase motors, the first is a 10HP (14FLA)and the second is a 30HP (40FLA) these two are to be fed from individual circuit breakers at a main lug panel and a fusible disconnect supplies the incoming power. how do you properly calculate for the correct size time delay fuses at the disconnect.
Top
Tools for Electricians:
#129517 - 04/05/05 06:29 PM Re: motor disconnect question
Redsy Offline
Member
Registered: 03/28/01
Posts: 2138
Loc: Bucks County PA
How about 430.63, which would, in your case put you at 430.62?
40A x 175% = 70A
70A + 14A = 84A
84A + the lighting and appliance load on the panel = Time Delay Fuse size?

[This message has been edited by Redsy (edited 04-05-2005).]
Top

Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box

Recent Posts
Forum Styles
by Admin
01/24/17 02:22 PM
License exam
by TRUE POWER
01/23/17 09:16 PM
Looking for older post
by sparkyinak
01/23/17 12:27 AM
Members: Non-Members: Did you know?
by Admin
01/22/17 02:34 PM
Safety at heights?
by HotLine1
01/21/17 08:51 PM

Who's Online
1 registered (Admin), 97 Guests and 14 Spiders online.
Key: Admin, Global Mod, Mod
New in the Gallery:
Desk-mounted "power-board"
Top Posters
gfretwell 9066
Trumpy 8560
pauluk 7693
HotLine1 6833
sparky 5545
Member Spotlight
Member Since: 08/17/06
Posts: 358

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