Stack Light Format

A few of our engineers are in a debate over what the green stack light should mean for a production cell.
Does anyone have a standard that they have used in the past?

Thanks

Tim

Hi
I normally use green for 'OK' , amber for 'NOT OK' and red for 'PRIORITY'

So, if an engineer or manager was on the floor, green means no problems, amber means i need help but manye a running repair situation, red means broken down / out of materials etc

We use the same concept as CJD1965.

We use a simular set up:
Green-OK to Run
Amber-Running
Red-Fault Condition

Green = in cycle
Amber = waiting for operator
Amber flashing = hurry up!!!!!!!
Red = Knackered read alarm messages for assistance

Ditto...

Green = good
Red = bad


However -- I have seen systems that were Green = safe (system OFF), Red = danger (system running) But this just seems backwards from every other color coding used in anyplace and tends to confuse people. Hopefully, you're not considering this...

OZEE said:

Ditto...

Green = good
Red = bad


However -- I have seen systems that were Green = safe (system OFF), Red = danger (system running) But this just seems backwards from every other color coding used in anyplace and tends to confuse people. Hopefully, you're not considering this...

Click to expand...

This is very standard in the power industry. Here red denotes the breaker is closed (thus supplying power) and green means open. I have never seen switchgear that was any other way. Since it was that was for the breakers, it usually spilled over into all the controls in the powerhouse. Red ON - Green OFF.

For me the biggest benefit is for you to develop a plant standard and then follow that standard throughout the plant. It really doesn't matter what colors are chosen if you are consistant everywhere. In addition, our standard here (which is green running, red stopped, yellow fault) we use a small sign beside every light to denote what it means. We also use blue and white lights to denote different things.

Red = STOP = warning unsafe
Green = GO = safe to go

On the other hand with machinery 'GREEN - Safe to GO' is actually machine is in a dangerous condition as it can mulch you up and spit you out in solids/liquids/gases... whilst 'RED - Unsafe' allows you to open up the contraption and get it to mop up your buddy!

Everyone reacts better to a red lamp!

I liked my previous employers standards...too bad they did not consistently use them throughout the plant:

AMBER=AUTO
BLUE=MANUAL
RED=STOP
GREEN=control power on (meaning it was ready to GO)
Flashing AMBER="Single cycle" or mode change in progress. Some machines would complete the current step when switched from AUTO to normal STOP or MANUAL, and the indicator would flash until it finished or timed out.
Flashing RED=Fault or Alarm

My new job uses purple for critical alarms and that works quite well for graphic displays, but I have not seen any purple lamps...

I usually have 2 Green states:
Green Solid = running
Green Flashing = All ok but not running

This way the floor manager knows if equipment is not being utilized from a distance.

However -- I have seen systems that were Green = safe (system OFF), Red = danger (system running) But this just seems backwards from every other color coding used in anyplace and tends to confuse people. Hopefully, you're not considering this...

Click to expand...

Ozee,

Please do not blame the Green/Off Red/On on backwards people. It was a NEMA (National Electrical Manufacturer's Association) standard for many, many years, and also a JIC (Joint Industrial Council) standard. If you were building electrical equipment to meet NEMA standards, you HAD to use that color code. Period. If you didn't care if you met NEMA standards, then you were free to use whatever you wanted.

When NEMA first introduced it, it made perfect sense to everyone. If you are walking across the street (most people did walk a lot back in those good old days), Red = Danger, but go. Green = Don't go, stay safe.

Over the years, perceptions here gradually changed, as America's facination with the automobile grew and grew. Walking/Not walking is no longer the first thing that the average American person thinks of when they see red and green lights. It seems that everyone in the U.S. now thinks of himself as being in the driver's seat AT ALL TIMES.

Does that say something about our inflated egos? Perhaps it says more about our lack of passenger transportation systems and the amount of time we spend in cars waiting at red lights.

One time I remember meeting the truck from the motor control center factory and climbing up and swapping all the red and green lens, before our customer got a chance to complain. The customer's written specifications had stated that the motor control center "must meet all NEMA standards", but it turned out that is not what he wanted. What he meant was that it should "meet all NEMA standards (except the ones I don't like)."

NEMA finally deleted that code, after much confusion. Now we have no NEMA color code standard (that I know about) for process functions.