panel indicator color scheme

[rmiell]

I need a little guidance on a project I want to complete for our ageing light plant.

Right now the generator section, as well as the circuit feeders out of our light plant have panel indicators on breakers and controls as follows: Breaker ON, amber light, breaker OFF, green light with a 2nd light that has been added that is red if breaker is off.

I believe that the colors should be as follows: Breaker ON= Red light, breaker OFF = green light, using the logic of if the breaker is on, red cautions you not to approach the breaker, while the green tells you it's ok to approach the breaker if it is off. We have a new (2007) substation which uses this color scheme for it's indicators.

I am looking into replacing all of the lamps with LED lamps, and I would like to correct the color scheme at the same time.

Now comes my major problem: In the same light plant, there are a number of motor controller centers, with motor starters installed in them. Each starter has indicator lights on it's face, with Power on/motor off = Red and Run = Green. I am not sure of the standard colors for this, but I think green is usually used for a run indication. Is red usually used for off indication on MCCs, or should this light be amber instead?

The same operator who will be opening and closing feeder breaker or putting generators online will be starting and stopping motors from the MCC, so I would like to make the indicators all mean the same thing, if possible.

Any comments or thoughts?

TIA

Rick Miell

 

[EEJaime]

I am not sure what exactly a "light plant" does, but in many cases in commercial applications you can define the color scheme however you want.

There are traditional color schemes that are specific to different industries and operations. One such is that a "Green board" uses the logic that when all systems are operating normally, all indicators are green. When there is a trouble alarm or warning, there is an amber indication. And where any system experiences a failure or is off, then the indication is red.

MCC's traditionally indicate red for motor "off" and green for motor running. Engine controls would be similar and would also include amber indications for low oil, high temperature, and other such warnings. Again it does not matter in many instances, how you define these as long as you are clear.

I am sure that there are very specific and strict guidelines for critical facilities such as power plants, military installations and the like, but I am not familiar with those.

 

[ScottyUK]

Have a search on this site - there were a few long threads discussing this. The power industry seems to prefer one standard, and the process industry prefers the exact opposite.

Our plant uses Red = running, Green = stop, except on the distributed control system which has the colours the opposite way around. Standars. Dontcha love 'em?


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[oldfieldguy]

I fight this little battle all the time.

In power distribution equipment, red=breaker closed, green=breaker open.

In process control equipment, including motor starters, red=off, green=running.

and EVERYBODY on both sides of the table has an opinion.



old field guy

 

[BJC]

"MCC's traditionally indicate red for motor "off" and green for motor running"
Not the tradition I have worked with for 40 years and on plants that go back to before MCCs were invented.
red= run= cable energized, danger. Green = not running, cabel de-energized, safe.

As far as I have found there is no standard on this. I would like to find one because right now we have a consultant who wants to do thing backwards.
Valves are another one people get wrong. Red light = valve open, Green light = valve closed, Both lights = some where inbetween.

 

[unclebob]

My two cents:

Use two lights any color:

1- Circuit energized = light on, de-energized = light off
2- Motor running = light on, stopped = light off

 

[slavag]

Hi
To Unclebob
My two cents:
light off---no supply to led .
On the site "on" is energaizer, dangerous- red color ( CB closed)
Green, of course, opposite.

In the SCADA red=Alarm, green always O.K.
Regards.
Slava

 

[jraef]

This is / has been / will be an endless debate. There ARE standards on this, all (that I have seen) of which contradict what some people are used to and have been doing for years. In one or two of the archived threads on this subject there are recognized standards cited to this effect.

Red = Stop, Green = Go is ONLY appropriate for traffic lights.

First, recognize that Indicator lights are DIFFERENT from Push Buttons.

Indicator Lights / Flags:
Red = On, Hot, Dangerous, Running
Green = Off, Safe, Ready, Stopped.

Push Buttons:
Red = Stop, Off, Close, De-energize
Green = Start, On, Open, Energize

BTW, I disagree with the statement that MCCs use Green lights for Run. Look in ANY MCC manufacturer's standard catalog under the control options and you will see that Run lights are always Red as standard. You can ask for them to be Green but if you don't and just specify a "Run Light", they will come red.

Roughly only 50% of the people in this forum will agree with me however... Then you run in to what YOUR facility is used to! If everyone in your plant is used to it being one way, then it may be dangerous to arbitrarily decide to change it. Wrong can be right if everyone is wrong.

Like ScottyUK said,
Standards, gotta love 'em.

 

[controlsdude]

USA
"Electrical Standard 13, the Operator's Control Stations and Equipment section of NFPA 79, clearly states the color and meaning of switches and lights. Some colors are preferred for various functions, but the color red is clearly "off" or "stopped." Table 8 of NFPA 79gives device/function examples with green meaning a safe condition, ready to start, cycle complete, or running under a safe condition. " quote

Red = off
Green = safe condition

But then as you say Red means CB is on in a power plant.

I always preferred if something is energized is a plain white indicator.
White = Power on

So whose spec are we following?

searched NEC shows indicators used for certain functions but no color scheme.

 

[jraef]

thread248-39408
thread238-182086
thread249-95626

 

[jraef]

And...

http://www.iprocessmart.com/techsmart/lightcodes.htm

Interestingly, if you read this (and other) synopses of NFPA 79 you will see that technically, there is NO RUN INDICATION mentioned! Red = Abnormal, green = Normal, safe, ready. But is a piece of machinery safe if it is running? Is that "normal"? If so, then how do you reconcile that with the concept of a "Normally Open" contactor meaning it is in the Off state?

More fuel for the fire...

http://www.lmpforum.com/inforum/index.php?showtopic=1918

http://forums.mikeholt.com/showthread.php?t=91620&highlight=pilot+light+color