Color of On-Off Lights

[hockeyoligist2]

The engineering Dept where I work specifies red for on (motor running), green for off, on all of our equipment and MCC's. That seems odd to me because all of my prior jobs were the opposite. Is their a rule on this or is it up to them? What do most of Y'all see or do?

 

[jim dungar]

The engineering Dept where I work specifies red for on (motor running), green for off, on all of our equipment and MCC's. That seems odd to me because all of my prior jobs were the opposite. Is their a rule on this or is it up to them? What do most of Y'all see or do?

There is no standard.
NFPA 79 has some recommendations but it is really up to each location, just like color coding of conductor phases.

The NFPA 79 light colors are:
Red - danger, process is in emergency state, equipment is faulty
Yellow/Amber - warning/caution - process is abnormal, equipment is abnormal
Green - safe, process is normal, equipment is normal.

 

[weressl]

The engineering Dept where I work specifies red for on (motor running), green for off, on all of our equipment and MCC's. That seems odd to me because all of my prior jobs were the opposite. Is their a rule on this or is it up to them? What do most of Y'all see or do?

Neverending binary debate with equally good arguments.

Green: ready, free to go.
Red: operating, be cautious, source of danger.

 

[celtic]

I go with the Green - OFF; Red - ON mentality.
Isn't that the coloring on some Air Circuit breakers?

 

[stickboy1375]

Reminds me when I went to a house with an alarm system, two LEDs (green/red) at the door with a key switch... yeah, I guessed wrong... Police officer was nice though...

 

[LarryFine]

I go with the Green - OFF; Red - ON mentality.
Isn't that the coloring on some Air Circuit breakers?

But your pic shows opposite of what you said.

 

[hockeyoligist2]

I may need to add something here........ The start buttons at work are green the stop buttons are red. We have separate lights indicating the status of the motors/machines. If it's running they are red, off they are green, trouble/fault yellow.

 

[jim dungar]

I may need to add something here........ The start buttons at work are green the stop buttons are red. We have separate lights indicating the status of the motors/machines. If it's running they are red, off they are green, trouble/fault yellow.

Pilot lights and pushbuttons often have opposite color meanings.

For example:
Green light on means machine is off/safe. Therefore push green button to change state.

Red light means machine is on/dangerous. Therefore push red button to change state.

 

[JohnHurst]

When I was designing equipment for some semiconductor capital equipment manufacturers, they stated that in most European factories the workers are trained that a red light is immediate cause to hit the Emergency Off switch.

 

[celtic]

But your pic shows opposite of what you said.

I can't actually SEE what's in the picture :smile: ..."looks" like a bucket with a red and a green square....and I haven't had the pleasure of working with the big stuff in a few years now.

 

[mdshunk]

I did some work in a hospital that had an old MCC in the original section, and a newer MCC in a more modern addition. The pilot lamps were different in each MCC. I traditionally see red for running and green for off. Seems sorta counter-intuitive, but you sorta get used to it. I mentally think of it like a traffic signal. Red for "stop, don't work on the motor because it's running", and Green for "safe to go and work on the motor".

 

[e57]

I can't actually SEE what's in the picture :smile: ..."looks" like a bucket with a red and a green square....and I haven't had the pleasure of working with the big stuff in a few years now.

It's the (for buttons) Euro/international red and green, off and on (O/I), stop and start or open/closed?????

Anyway, IMO there should be no light in the "off" at all. Unless it is yellow, indicating the machine is powered, or green only if there is an addition safety device like a lock-out for safety that is engaged. Red (as an indicating light) should only be a hazard or fault of some sort. Well - you could illuminate the "STOP" button in red....

 

[Overkill]

The engineering Dept where I work specifies red for on (motor running), green for off, on all of our equipment and MCC's. That seems odd to me because all of my prior jobs were the opposite. Is their a rule on this or is it up to them? What do most of Y'all see or do?

When I first started in this business, it was green, machine running, red, machine down. Then about 4 years ago, out of the blue with no explanation, it got switched. I have no idea why or know of no rule, or don't know where it originated from. But red, machine running...danger, green, machine down...safe, is the norm now.

 

[benaround]

I like to use a red lamp inside the green indicator.

 

[petersonra]

Most of our customers spec it one way or the other. Its pretty close to 50/50 as to whether red is running or not running.

Chemical plants and power stations seem to more commonly use red = not running.

Most industrial plants follow the NEMA/NFPA79 standard of red=running.

However, I have also seen a fair number of plants where they have both, sometimes on equipment sitting right next to each other. Once I was in a place where everything on the ground floor was one way, and it was the other way on the other floors.

I have seen many times where the physical equipment running/not running lights are color coded exactly the opposite as on the HMI panels for the same piece of equipment.

I did a painted color graphic panel one time where the end user insisted that motors use red=running, and valves use red=closed.

A job I did for the navy used all white lights for status indication of motors. It had a white light for running, and another white light next to it for not running. They were concerned about color blind people.

 

[LarryFine]

"I watched you very carefully. Red light stop, green light go, yellow light go very fast. " ~ Starman