NEC 404.7 Switches/Indicating - "On" and "Off" vs. "I" and "O"

Status
Not open for further replies.
J

jimiphx

New User
Location
Phoenix, AZ
NEC 404.7 Switches/Indicating - "On" and "Off" vs. "I" and "O"

Folks,

Does the NEC recognize "I" and "O" for "On" and "Off" respectively as allowable indicators to meet 404.7?

Thanks,

Jimi
 
The requirement is that they clearly indicate on and off, not necessarily that those words are used. Although it may be confusing to some IMO 1 and 0 is indicative of being on or off.

Welcome to the Forum. :)
 
I and O are the international standard. Since the NEC is supposed to be an international standard, this could be a code change for submission.
 
tom baker said:
I and O are the international standard. Since the NEC is supposed to be an international standard, this could be a code change for submission.
Click to expand...

The NEC simply says there must be some type of clear indication of Open and Closed. Parenthetically it equates Open = Off and Closed = On.
The only specific instruction given is that when vertically mounted, the closed position is up unless it is a double throw device.

I and 0 symbols and color combinations, like Black and Red or Green and Red, have all commonly been used to indicate On-Off in the US for close to 30 years now.
 
jim dungar said:
....
I and 0 symbols and color combinations, like Black and Red or Green and Red, have all commonly been used to indicate On-Off in the US for close to 30 years now.
Click to expand...
Without some other indication, I would have no idea what green and red means as far as off and on, since those colors are used both ways in the electrical industry in the US.
 
don_resqcapt19 said:
Without some other indication, I would have no idea what green and red means as far as off and on, since those colors are used both ways in the electrical industry in the US.
Click to expand...
:thumbsup:
Green is go and red is stop (automotive model) OR
Green is safe (not running) and red is dangerous (running.)
 
Imagine how confused the average user (and some installers) would be if we marked the face of a typical toggle switch with "open" and "closed" instead of "on" and "off"
 
don_resqcapt19 said:
Without some other indication, I would have no idea what green and red means as far as off and on, since those colors are used both ways in the electrical industry in the US.
Click to expand...

I agree, especially when looking at indicating lights. NFPA79 and UL508A have suggestions but they are universally applicable.

I think it has been more than 20 years since I have seen a red colored button that did not mean Off, but I know some exist.
I and O have been found on household 'electronic' devices for decades, so why would we need a change to the NEC?
 
Status
Not open for further replies.
Top