ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Recent Posts
VFD MotorFeeders
by gfretwell. 10/19/17 01:02 AM
Generator Cable Sizing
by brsele. 10/18/17 07:39 PM
What do you do?
by gfretwell. 10/17/17 01:08 AM
Good ol' copper pipe in the fuse holder trick
by HotLine1. 10/16/17 07:16 PM
Another generator question
by HotLine1. 10/16/17 07:02 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
241,389 Are you busy
177,346 Re: Forum
168,959 Need opinion
Who's Online Now
0 registered members (), 35 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#214021 - 09/24/14 01:25 AM Demand Factor or Load Computations  
mdelz10  Offline
New Member
Joined: Sep 2014
Posts: 2
Philippines
Guys can you help me to understand the purpose of demand and diversity factors and how to use it in making a load schedule.. thanks in advance ^^


Work Gear for Electricians and the Trades

#214023 - 09/24/14 01:34 AM Re: Demand Factor or Load Computations [Re: mdelz10]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,123
Estero,Fl,usa
Diversity is simply realizing that you probably will not turn on everything you have at the same time (they never met my daughter)
Diversity shows up most in residential calculations. In industrial settings it would not be unusual to compute everything at 100% of it's rating plus the applicable overhead where necessary since it is on when the plant is operating.
Usually we have engineers doing that here on the mainland if this is a big operation.


Greg Fretwell

#214024 - 09/24/14 01:46 AM Re: Demand Factor or Load Computations [Re: mdelz10]  
mdelz10  Offline
New Member
Joined: Sep 2014
Posts: 2
Philippines
^^ sir can you teach me to use this diversity and demand factor in residential area. all I know is I need this factors to compute the load schedule, branch circuit, feeder and main service entrance.


#214027 - 09/24/14 02:02 AM Re: Demand Factor or Load Computations [Re: mdelz10]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,123
Estero,Fl,usa
It is a little complicated at first. It is usually best to start by looking at a few. Basically you start with the square footage at 3va per sq/ft, apply a correction factor to that and then start adding in the fixed equipment.
There are actually 2 methods you can use.

There are examples in the back of the NEC book but you can also find some work sheets and even a couple Excel templates on the net.

Here are a few examples.

https://www.modestogov.com/forms/pdf/bds_res_electrical-load.pdf

http://www.zenfixit.com/load_calculations.shtml

https://www.mikeholt.com/documents/calculations/formulas/ResidentialLoadCalculations.xls



Greg Fretwell


Member Spotlight
Samurai
Samurai
Fl.
Posts: 46
Joined: May 2007
Show All Member Profiles 
Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.013s Queries: 15 (0.003s) Memory: 0.7604 MB (Peak: 0.8922 MB) Zlib enabled. Server Time: 2017-10-19 10:55:27 UTC