ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Baseboard Mounted Light Bulb Socket
by SPSchuman. 07/15/19 03:22 PM
Hunter Fan Recalls Brunswick 3 & 4 Light Fans
by Admin. 07/11/19 11:08 AM
Honeywell Recalls some Smoke Sensors
by Admin. 07/11/19 11:03 AM
New in the Gallery:
What is this for?
Plug terminals
Who's Online Now
0 registered members (), 9 guests, and 7 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Sizing a disconnect for a Unit Heater #68395
08/05/06 06:27 PM
08/05/06 06:27 PM
C
Cinner  Offline OP
Member
Joined: Dec 2004
Posts: 78
Kelowna, B.C., Canada
A 3000 watt unit heater is to be installed in a storage room...it has a fan built in... but is does not have a HP rating...3 phase 208 volts...what size disconnect is required?

Work Gear for Electricians and the Trades
Re: Sizing a disconnect for a Unit Heater #68396
08/05/06 07:10 PM
08/05/06 07:10 PM
Tom  Offline
Member
Joined: Jan 2001
Posts: 1,044
Shinnston, WV USA
The motor load for a unit heater this small is unlikey to exceed 1/8th HP. If you were to use a standard safety switch, a 3 pole 30 amp switch would do the trick.

An alternative would be a 3 pole switch such as a Hubbell HBL7810BW. This type of switch is made by others, but that is the only catalog # I have handy. This switch will cost about as much as a safety switch and will probably need to be ordered.

You may not need a disconnect at the heater if the circuit breaker complies with 424.19(B)(1)


Few things are harder to put up with than the annoyance of a good example.
Re: Sizing a disconnect for a Unit Heater #68397
08/09/06 10:47 PM
08/09/06 10:47 PM
R
RobbieD  Offline
Member
Joined: Feb 2003
Posts: 231
Canada
15 Amp three phase breaker

[This message has been edited by RobbieD (edited 08-09-2006).]


Featured:

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

 

Member Spotlight
togol
togol
NW In. USA
Posts: 421
Joined: September 2005
Show All Member Profiles 
Top Posters(30 Days)
Admin 5
Popular Topics(Views)
257,121 Are you busy
192,952 Re: Forum
182,607 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.020s Queries: 14 (0.004s) Memory: 0.9514 MB (Peak: 1.0763 MB) Zlib enabled. Server Time: 2019-07-20 06:10:35 UTC