Box Fill - Reliable Calculators? - Electrical - DIY Chatroom Home Improvement Forum

 DIY Chatroom Home Improvement Forum Box fill - Reliable calculators?
 Register Blogs Articles Rewards Search Today's Posts Mark Forums Read

12-17-2011, 12:08 PM   #1
Member

Join Date: Dec 2011
Posts: 108
Rewards Points: 75

## Box fill - Reliable calculators?

The various exceptions and writing of the NEC have me a bit tripped up on this.

Are there any ONLINE box fill calculator that someone cant point me to that are reliable/accurate?

The numbers I'm getting dont seem to match anything.

I have a 3 gang box with:
2 x 12/2 (4 x 2.25)
3 x 14/2 (6 x 2.00)
3 devices - 2 conductors each, so is it (6 x 2.25) or (4 x 2.25 + 2 x 2.00)?
internal clamps (2.25)
Largest ground (2.25)

So I've got: 9 + 12 + 13.5 + 2 + 2.25 = 39.00

http://www.constructionmonkey.com/ca...l/boxfill.aspx
Gives me 32.30

Where am I going wrong?

Last edited by fuzzball03; 12-17-2011 at 12:19 PM.

12-17-2011, 12:40 PM   #2
Electrical Contractor

Join Date: Jun 2004
Location: Newnan GA
Posts: 6,774
Rewards Points: 142

I come up with 39.
The online calculator missed the ground wire, and missed on the # of devices.

__________________
"The problem isn't that Hillary Clinton lies. We all know she lies. The problem is that her supporters don't seem to care"

 The Following User Says Thank You to jbfan For This Useful Post: fuzzball03 (12-18-2011)
 12-17-2011, 12:49 PM #3 Member   Join Date: Mar 2011 Location: MA Posts: 835 Rewards Points: 734 It's not you. The calculator is only counting the devices as a single conductor. I have a 3 gang box with: 2 x 12/2 (4 x 2.25) 3 x 14/2 (6 x 2.00) 3 devices - 2 conductors each (4 x 2.25 + 2 x 2.00) largest conductor connected to the device. internal clamps (2.25) Largest ground (2.25) Should read: 9 + 12 + 13 + 2.25 + 2.25 = 38.5 Last edited by AandPDan; 12-17-2011 at 12:53 PM. Reason: math error - figures!
 The Following User Says Thank You to AandPDan For This Useful Post: fuzzball03 (12-18-2011)
 12-17-2011, 04:22 PM #4 Member   Join Date: Dec 2011 Posts: 108 Rewards Points: 75 Great. thanks guys

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are Off Pingbacks are Off Refbacks are Off Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post lonewolf22 Plumbing 5 11-30-2011 08:03 AM IRuehl Landscaping & Lawn Care 7 08-27-2011 05:30 PM Roundeye Plumbing 11 07-26-2011 02:17 PM Piedmont Landscaping & Lawn Care 4 05-14-2009 09:14 PM ssybert Building & Construction 5 06-12-2008 07:19 AM

Top of Page | View New Posts