The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
On Delay Relay with Auto Reset
by Potseal
12/01/16 09:59 AM
Wow, that was close!
by jraef
11/28/16 07:06 PM
Earthquake in New Zeeland
by RODALCO
11/27/16 11:25 PM
Calling all Non-US members!! (Non-US only)
by Tjia1981
11/27/16 06:33 AM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 13
HotLine1 9
Texas_Ranger 8
Trumpy 8
sparkyinak 7
Who's Online
0 registered (), 81 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#83197 - 01/19/03 07:21 PM Water Heaters
sparky*62 Offline
Member

Registered: 07/27/02
Posts: 20
Loc: Ca.
I'm a little confused. The code states that the overcurrent device for an appliance that is rated 13.3a cannot exceed 150 percent.And that a branch circuit for a 120 gal or less water heater can't have a rating of less than 125 percent. A common size for water heaters are usually 4500w.4500 divided by 125% is 23.4, and 4500 divided by 150% is 28.1. So is it legal to use 12guage wire and put it on 25a overcurrent device. Or do I have to go 10gauge and put it on a 25a device.I am aware of section 240-3 for ampacities of conductors on 12g wire .Or am I looking in the wrong place? This is for a house.

Top
2014 / 2011 NEC & Related Books and Study Guides
#83198 - 01/19/03 08:21 PM Re: Water Heaters
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
As the 18.75 amps (4500/240) is more than 80% of the "normal" ampacity for #12 (20 amps), we/I would install #10 wire. You may be able to use #12 "by the book", but "the book" is minimum!
John
_________________________
John

Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals