ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
Blo breaker
by Admin - 07/07/20 02:42 PM
"Electric furnaces" and other odd American heaters
by gfretwell - 07/05/20 12:37 PM
Questioning the electrical norms
by gfretwell - 07/05/20 12:03 AM
PC has killed Experimentation?
by LongRunner - 07/04/20 02:37 PM
Lock-down Thread
by LongRunner - 07/02/20 05:56 AM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
0 registered members (), 22 guests, and 12 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Mistake in Instructions? #220351 10/27/19 10:04 PM
Joined: Mar 2004
Posts: 767
B
BigB Offline OP
Member
These are online instructions for a 40 amp EV charger. Note the sentence in the red box.

Attached Files juicepro.JPG
Work Gear for Electricians and the Trades
Re: Mistake in Instructions? [Re: BigB] #220354 10/28/19 05:19 AM
Joined: Sep 2011
Posts: 21
A
ampherder Online Content
Member
12 AWG ground on a 40 amp breaker is what is allowed in T250.122.

Re: Mistake in Instructions? [Re: ampherder] #220355 10/28/19 09:34 AM
Joined: Mar 2004
Posts: 767
B
BigB Offline OP
Member
Originally Posted by ampherder
12 AWG ground on a 40 amp breaker is what is allowed in T250.122.


I see that now, I wasn't aware it had changed

Re: Mistake in Instructions? [Re: BigB] #220356 10/28/19 01:41 PM
Joined: Jul 2004
Posts: 9,499
G
gfretwell Offline
Member
I understand table 250-.122 may be confusing to read but it says
Rating or Setting of
Automatic Overcurrent
Device in Circuit Ahead
of Equipment, Conduit, etc.,
Not Exceeding
(Amperes)

20 12ga copper
60 10ga copper

I read that to say if you exceed 20a and do not exceed 60a you are in a #10.
Just as a sanity check, what size is the ground in a 10ga or 8 ga cable ... 10ga


Greg Fretwell
Re: Mistake in Instructions? [Re: gfretwell] #220357 10/28/19 06:51 PM
Joined: Mar 2004
Posts: 767
B
BigB Offline OP
Member
OK yes that makes sense. They made it a bit confusing when they took out the 30 and 40 amp columns just because we were so used to seeing those numbers included but when you think about it they weren't necessary when the higher amperage columns jump from conductor size to conductor size with no repetition. So the instructions for the EV charger are incorrect.

Re: Mistake in Instructions? [Re: BigB] #220358 10/28/19 07:36 PM
Joined: Jul 2004
Posts: 9,499
G
gfretwell Offline
Member
Yes the OP was right and the EV instructions were wrong.
They made the change in format to T 250.122 in the 2011 cycle but the rule didn't change.


Greg Fretwell

Featured:

2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

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

 

Member Spotlight
akmaster
akmaster
alaska
Posts: 74
Joined: June 2012
Show All Member Profiles 
Top Posters(30 Days)
Admin 8
Popular Topics(Views)
267,213 Are you busy
201,912 Re: Forum
190,525 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3