ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Photocell
by twh. 01/22/18 05:06 PM
AreMetal Ladders Ever OK For Electrical Work?
by gfretwell. 01/22/18 01:15 AM
VDE 0100 to introduce AFCIs
by sparky. 01/20/18 05:09 PM
MRI LED lights dimmer control replacement - wow!
by Potseal. 01/19/18 08:52 PM
New in the Gallery:
Housebilding DIY wiring
SE cable question
Who's Online Now
0 registered members (), 26 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Demand factors for refrigerators in a laboratory #194004
05/04/10 06:21 PM
05/04/10 06:21 PM
B
Bravo  Offline OP
Member
Joined: May 2010
Posts: 30
NY, USA
Can I apply table 220.56 - demand factors for kitchen equip to laboratory refrigerators? The refrigerators are intermittent in use similiar to kitchen ref's.

thanks in advance.

2017 / 2014 NEC & Related Books and Study Guides
Re: Demand factors for refrigerators in a laboratory [Re: Bravo] #194006
05/04/10 07:03 PM
05/04/10 07:03 PM
G
gfretwell  Offline

Member
Joined: Jul 2004
Posts: 9,167
Estero,Fl,usa
I vote no. Refrigerators are basically motors.
I see this being 220.14(C) referencing 430.24

(125% of the biggest motor plus 100% of the rest).

If you are coming back from a power failure every one of those reefers will be presenting LRA at the same time. Depending on where you are, that can be a fairly frequent thing.

I am open to being wrong tho. wink



Greg Fretwell
Re: Demand factors for refrigerators in a laboratory [Re: gfretwell] #194024
05/05/10 09:12 AM
05/05/10 09:12 AM
G
George Little  Offline
Member
Joined: Jan 2004
Posts: 1,489
Michigan USA
I'm going to agree with Greg on this one for the reason he mentioned plus if we are talking about refrigeration type equipment there is nothing in Article 440 that I am aware of that allows us to apply a demand factor.


George Little
Re: Demand factors for refrigerators in a laboratory [Re: George Little] #194032
05/05/10 01:45 PM
05/05/10 01:45 PM
HotLine1  Offline

Member
Joined: Apr 2002
Posts: 6,918
Brick, NJ USA
Agree with Greg and George!


John
Re: Demand factors for refrigerators in a laboratory [Re: HotLine1] #194035
05/05/10 03:24 PM
05/05/10 03:24 PM
G
ghost307  Offline
Member
Joined: May 2005
Posts: 927
Chicago Illinois USA
Greg bring up an excellent point. After a power failure, that refrigerator will be running as a continuous load until it gets its contents cooled down. Some of that laboratory refrigerators that I've done go down to way below -100 degrees.


Ghost307
Re: Demand factors for refrigerators in a laboratory [Re: ghost307] #194049
05/06/10 11:28 AM
05/06/10 11:28 AM
B
Bravo  Offline OP
Member
Joined: May 2010
Posts: 30
NY, USA
thanks guys. I will size 125% of the biggest motor plus 100% of the remainders.


Featured:

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

 

Member Spotlight
NickD
NickD
Amish Country, PA
Posts: 46
Joined: March 2013
Show All Member Profiles 
Top Posters(30 Days)
Admin 21
sparky 15
Potseal 15
Popular Topics(Views)
243,595 Are you busy
180,393 Re: Forum
170,863 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.016s Queries: 15 (0.005s) Memory: 0.9751 MB (Peak: 1.1228 MB) Zlib enabled. Server Time: 2018-01-22 23:56:38 UTC