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

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jimiphx

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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
 

infinity

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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. :)
 

jim dungar

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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.

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.
 

don_resqcapt19

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....
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.
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.
 

GoldDigger

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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.
:thumbsup:
Green is go and red is stop (automotive model) OR
Green is safe (not running) and red is dangerous (running.)
 

kwired

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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"
 

jim dungar

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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.

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?
 
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