CLICK HERE AND JOIN OUR COMMUNITY TODAY, IT'S FREE!
Go Back   Electrician Talk - Professional Electrical Contractors Forum > Electrical Trade Topics > Commercial Electrical Forum

Reply
 
Thread Tools Search this Thread Display Modes
Old 05-01-2011, 01:05 PM   #1
Senior Member
 
Join Date: Nov 2010
Location: florida
Posts: 334
Rewards Points: 268
Default 3 phase calculations.

Hi guys, I have a 3phase sub panel and I need help figuring out the most efficient way to find out how much power is being consumed.Thanks for the help...Its a 3phase 120/208 being fed from a 480/3phase 100amp panel...


Last edited by knowledge29; 05-01-2011 at 04:54 PM.
knowledge29 is offline   Reply With Quote
The Following User Says Thank You to knowledge29 For This Useful Post:
johnsmithabe (05-19-2011)
Join Contractor Talk

Join the #1 Electrician Forum Today - It's Totally Free!

ElectricianTalk.com - Are you a Professional Electrical Contractor? If so we invite you to join our community and see what it has to offer. Our site is specifically designed for you and it's the leading place for electricians to meet online. No homeowners asking DIY questions. Just fellow tradesmen who enjoy talking about their business, their trade, and anything else that comes up. No matter what your specialty is you'll find that ElectricianTalk.com is a great community to join. Best of all it's totally free!

Join ElectricianTalk.com - Click Here JOIN FOR FREE


Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. ElectricianTalk.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task!

Old 05-01-2011, 01:57 PM   #2
Senior Member
 
Join Date: Mar 2009
Location: Texas
Posts: 567
Rewards Points: 500
Default

Quote:
Originally Posted by knowledge29
Hi guys, I have a 3phase sub panel and I need help figuring out the most efficient way to find out how much current is being consumed.Thanks for the help...Its a 3phase 120/208 being fed from a 480/3phase 100amp panel...
Power is consumed, current is not.

Either;
turn every thing on and do a current measurement,
find each individual load and do a load calculation,
use a recording power meter for a number of days.

Why do you need this information? Are you planning on adding an additional load to this panel?

K2500 is offline   Reply With Quote
The Following User Says Thank You to K2500 For This Useful Post:
johnsmithabe (05-19-2011)
Old 05-01-2011, 03:54 PM   #3
Registered Member
 
Join Date: Aug 2010
Location: georgia
Posts: 10,305
Rewards Points: 2,000
Default Product

Try these. They are great

http://www.emon.com/products.html
Cletis is offline   Reply With Quote
Old 05-01-2011, 04:52 PM   #4
Senior Member
 
Join Date: Nov 2010
Location: florida
Posts: 334
Rewards Points: 268
Default

yes,I am planning on installing a 17hp vac systems for a cnc router.
knowledge29 is offline   Reply With Quote
Old 05-01-2011, 11:02 PM   #5
Inspector
 
electures's Avatar
 
Join Date: Oct 2008
Location: The Great Police State of South Jersey
Posts: 331
Rewards Points: 270
Default

Quote:
Originally Posted by knowledge29 View Post
Hi guys, I have a 3phase sub panel and I need help figuring out the most efficient way to find out how much power is being consumed.Thanks for the help...Its a 3phase 120/208 being fed from a 480/3phase 100amp panel...
Amprobe it or calculate the load.
electures is offline   Reply With Quote
Old 05-02-2011, 07:34 PM   #6
Member
 
Join Date: Sep 2010
Location: alaska
Posts: 34
Rewards Points: 25
Default

if you dont know the calculated load of the panel based upon all the connected load, then you should get a recording meter and test it for 30 days to find max and average load.
tgreen is offline   Reply With Quote
Old 05-08-2011, 11:46 PM   #7
Senior Member
 
Join Date: May 2011
Location: Edmonton, Canada
Posts: 373
Rewards Points: 250
Default

Quote:
Originally Posted by tgreen View Post
if you dont know the calculated load of the panel based upon all the connected load, then you should get a recording meter and test it for 30 days to find max and average load.

A power quality meter would be best yes, however, if this is your only panel in the plant or site, you could call the power company and they can give you a 12 month readout of consumption, PF, and any 3rd harmonics you might be dealing with. Depending on the PF of the Vac, you might want to consider some PFC to reduce your inductive load a little, and reduce long term power costs.

just my 2c
l0sts0ul is offline   Reply With Quote
Old 05-11-2011, 06:14 PM   #8
Junior Member
 
Join Date: May 2011
Location: United Kingdom
Posts: 6
Rewards Points: 10
Default

remember to carry the 1
alfie1984 is offline   Reply With Quote
Old 05-12-2011, 04:11 AM   #9
Senior Member
 
Join Date: Feb 2007
Location: Eighty Four,Pa.15330
Posts: 7,258
Rewards Points: 2,276
Default

Quote:
Originally Posted by knowledge29 View Post
Hi guys, I have a 3phase sub panel and I need help figuring out the most efficient way to find out how much power is being consumed.Thanks for the help...Its a 3phase 120/208 being fed from a 480/3phase 100amp panel...
It will go "Blooowey"
bobelectric is offline   Reply With Quote
Old 05-19-2011, 07:01 AM   #10
Member
 
Join Date: May 2011
Location: United States
Posts: 76
Rewards Points: 75
Default

Why u r installing? Wats ur purpose?
johnsmithabe is offline   Reply With Quote
Old 05-19-2011, 12:08 PM   #11
Member
 
Join Date: Sep 2010
Location: alaska
Posts: 34
Rewards Points: 25
Default

Bob had a good catch on this, i didnt even see that they were feeding a 208 panel from a 480 panel.

I guess im just used to speaking with professionals all day,

tgreen is offline   Reply With Quote
The Following User Says Thank You to tgreen For This Useful Post:
johnsmithabe (05-20-2011)
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Load Calculations 6506gary General Electrical Discussion 18 04-11-2011 08:42 AM
Spa calculations Tapeman General Electrical Discussion 3 09-13-2009 11:14 PM
Math Calculations Hogger NEC Code Forum 11 04-11-2009 09:14 PM
load calculations Please Help powerline General Electrical Discussion 1 03-04-2009 08:44 PM
Service Calculations. agoolay General Electrical Discussion 4 04-07-2007 02:36 PM


All times are GMT -4. The time now is 02:09 AM.


Copyright 2006-2014 Escalate Media LP. All Rights Reserved
Our Pro Sites Network
ContractorTalk.com | DrywallTalk.com | HVACSite.com | PaintTalk.com | PlumbingZone.com | RoofingTalk.com