ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Photo Editing Software?
by Fridayrack - 12/03/21 05:05 AM
Square D "All-In-One" Panelboard
by NORCAL - 11/30/21 12:48 PM
Where is Everyone?
by luckyshadow - 11/21/21 10:14 AM
It's been an interesting career
by The Watt Doctor - 11/19/21 09:56 AM
Well I am back to stay (nearly 6 years)
by The Watt Doctor - 11/19/21 09:17 AM
New in the Gallery:
240/208 to a house
240/208 to a house
by wa2ise, October 9
Now you know.
Now you know.
by Tom_Horne, September 7
Who's Online Now
1 members (Scott35), 16 guests, and 20 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#189090 09/18/09 06:15 PM
Joined: Apr 2007
Posts: 8
J
jem Offline OP
New Member
I have been coming accross these Heil brand gas furnaces that do not have the MCA and MOCP on the nameplate. They list the maximum input current which I think is what the unit is rated. How do I calculate these values.

2017 / 2014 NEC & Related Books and Study Guides
Joined: Jul 2004
Posts: 9,672
Likes: 7
G
Member
This usually applies to HVAC compressors. Does this furnace have anything more than a blower, igniter and some controls?
When in doubt use 310.16 and 240.4(D)


Greg Fretwell
Joined: Apr 2007
Posts: 8
J
jem Offline OP
New Member
There is also a small combustion blower.

Joined: Jan 2004
Posts: 1,507
G
Member
Look at the manufacturer's installation guide for the furnace. Usually they will tell you what size circuit. Some even tell you what size wire to run and depending on the length of the run they may have you increase to the next size wire. I'm seeing some of your larger furnaces specify a 20a. circuit.


George Little

Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *

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

 

Member Spotlight
Joe Tedesco
Joe Tedesco
Boston, Massachusetts USA
Posts: 2,749
Joined: October 2000
Top Posters(30 Days)
Admin 3
dsk 2
Popular Topics(Views)
286,517 Are you busy
218,948 Re: Forum
205,072 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5