ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Using THWN on automotive circuits
by BigB - 03/23/23 11:19 AM
Continuous load
by HotLine1 - 03/08/23 02:11 PM
How's all our Non-US folks doing?
by dsk - 03/08/23 11:56 AM
Old Computers?
by Bill Addiss - 03/04/23 05:06 PM
New in the Gallery:
Burger King crown sillyness
Burger King crown sillyness
by wa2ise, December 11
240/208 to a house
240/208 to a house
by wa2ise, October 9
Who's Online Now
0 members (), 128 guests, and 12 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#74705 02/02/07 11:34 AM
Joined: Dec 2003
Posts: 15
R
Rob Offline OP
Member
How do you determine operating cost of a 3 phase motor. 460 volt 15 amp.
My utility rate is .08 cents per kwh.
Is there a common formula?

#74706 02/02/07 11:58 AM
Joined: Jan 2005
Posts: 5,370
Likes: 1
Cat Servant
Member
Measure the actual amps drawn on each leg. Average. Multiply by 1.73. That's your amp load.

From there, it's the usual amps x volts x time x rate = electrical cost.

This will give you figures good enough to work with. Actual results will vary a bit, due to changes in load, power factor, harmonics, etc ... but the number you get will be close enough for budgeting.

#74707 02/02/07 06:20 PM
Joined: Jul 2001
Posts: 599
J
JBD Offline
Member
One quick and dirty method is to estimate 1KVA of input power for each HP of output.

For a fully loaded motor you can use 1KW per HP. For lightly loaded motors use 1.1KW per HP instead.


Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *
2023 National Electrical Code (NEC)
2023 NEC Now Available!
 
* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
dougwells
dougwells
kamloops BC Canada
Posts: 1,158
Joined: May 2003
Top Posters(30 Days)
BigB 3
triple 2
Popular Topics(Views)
305,039 Are you busy
233,457 Re: Forum
218,144 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5