Red for on or green for on

What colour should the run lamp be?

  • Red

    Votes: 22 17.5%
  • Green

    Votes: 100 79.4%
  • Other

    Votes: 4 3.2%

  • Total voters
    126

Johnny T

Member
Join Date
Jul 2003
Location
Fife, Scotland
Posts
642
Just been visiting a site that uses red lamps to indicate that a machine is on and green lamps to indicate that a machine is off.. the logic being that if it is on the red lamp indicates there is a potential danger.

Seems a bit daft to me as, going by the logic of traffic lights, green should be go (run) and red stop.

Just wondered what the balance of opinion was and if, anywhere in the world, there was any kind of standard for this...

Sad question, I know, but its Friday afternoon and so I'm just winding down for the weekend.

JT ;-)
 
I hate the Red on/open/danger and Green off/closed/safe convention. I think it came from the power generation industry. It is incredibly couter-intuitive to most operators, and in my experience most operators hate it as well.
 
For me, for 10 years it was Green=ON, Red=OFF for HMI graphic indication.

Then I helped build a plant where they decided prior to my involvement to do as you said, for the same reasons. Red = On = Unsafe to perform maintenance on etc.. Someone said the person who made that call had never been in the process world but came from U.S.Navy Nuke Submarines, I don't know if that is true or not. Any jarheads out there to confirm that?

I was there for 4 years and I swear it took me a year to get that burned into my brain because I spent 10 years doing just the opposite. For the past 4 years I've been back in the Green=ON/ Green=Open/ Flashing red=Failure or alarm world.
 
I wish someone would come out with a standard, if you want bizzare try my current place. A buzzer goes off together with a flashing orange lamp to warn of start-up, a blue lamp comes on with a fault. Unless its a pick up point where the conveyor only starts when there's something to deliver onto it, it flashes orange all the time its enabled.

We have a couple of places where green lamps are, F..k knows what their for?

The system you talk about seems perfect sense really, except red would normally be for fault.


Another question on lamps, each emergency stop and safety device we have has a lamp next to it, which when the device is operated the lamp goes on. This is a massive conveyor hall with E-Stops dotted around everywhere.

I would prefer the lamp always on, off when operated, this way if the lamp fails you will see it, not find out after you've been looking for a damned E-Stop for hours.
 
For Estops I like to have the red lamp flashing if the fault/safety breach condition is still active and then solid for when the safety circuit can be reset.

I can understand your point of view though if you have loads of estops. Plus, doing it my way there's no way of knowing if the lamp has blown..

Tom, you are perfectly correct that it is very counter intuitive. It was probably dreamt up by some shiny a*se in an office somewhere who was trying to make an impression with his boss...
 
I drive up to a busy intersection and I want to cross.

A red light tells me that the action I want to take is not safe to do so at this time. I wait for the green.

I continue on to arrive at a railway crossing only to find that there is a red light announcing an approaching train.

A red light tells me that the action I want to take is not safe to do so at this time. I wait for the red to go out. (and the train to pass)

I continue into my workplace and walk up to a 15KV vacuum breaker which I am suppossed to rack out to isolate for maintenance.

A red light tells me that the action I want to take is not safe to do so at this time. I wait for the green.

At the HMI where I am not in a position to be harmed (hopefully), I understand that the colour represents the state of the machine and is not being used to tell me what I can safely do.

If I was waiting for a permissive to safely proceed I hope I would be given a big red stop sign symbol.

Brian.
 
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As far as E-Stops, after working in a meat processing plant with tons of mushroom-head maintained, lighted e-stop PBs. We sensed from the e-stop circuit (PLC IN) which button had been pushed and flashed the corresponding light (PLC OUT) because we got tired of people freaking out because the line was down when it turned out an E-Stop had been pushed (many times by accident). Also had indication on HMI's so safety would be expedited in the event of an actual emergency situation. Light would remain flashing until the button had been pulled back out and 'E-Stop Reset' had been pushed, then light would be back to steady on.

To add to the confusion, the current person I work for want's a pushbutton on a screen to be the color of the current status of the device (even though the status is directly above the button, with colored background) I think the button should be red if you want to stop/close the device and green on the button if you want to start/open a device. We use one button that changes from Start/Open to Stop/ Close. I guess I think it should match a field or MCC mounted start/ stop station that has two buttons. One red for stopping, one green for starting.
 
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I use green for running or open and red for stopped or closed. I also take the traffic light analogy a little further and use yellow for alarms and waringings. For an undetermined state I use blue (neither LS on a valve is on).I have worked at places where they use red as running and green as stopped. It always confuses me - I look at the screens and think to myself "**** - why is that pump not running?", then after a mild 5 second panic I think "Oh, it is.".
 
There is a standard for this - for us Europeans anyway, standards for actuator and indicator light colours (and just about everything else to do with machine wiring) are covered in:

EN60204-1:2006 'Safety of Machinery - Electrical equipment of machines - Part 1: General requirements'

I've scanned in a couple of pages covering actuator and indicator light colours - I don't want to post it here for obvious reasons....

PM me if you want a copy....


Kevin H
 
cntrlfrk said:
Someone said the person who made that call had never been in the process world but came from U.S.Navy Nuke Submarines, I don't know if that is true or not.

Any jarheads out there to confirm that?

Jarheads are MARINES not SAILORS aka SQUIDS.

BTW, all US NAVY nukes have a mysterious green glow about them.

I have been to wide variety of plants and countries and seen many manufacturer's equipment doing service work. Typically RED is off and GREEN is on.
 
Leadfoot said:
Jarheads are MARINES not SAILORS aka SQUIDS.

My apologies to the honorable men and women who serve this country.

What I meant was 'Bubbleheads'.

(Hope that isn't a derogatory reference)
 
cntrlfrk said:
My apologies to the honorable men and women who serve this country.

What I meant was 'Bubbleheads'.

(Hope that isn't a derogatory reference)

That's not derogatory. Now if you had said that submariners are stupid for wanting to go on a boat that sinks on purpose, or something about how they like to go down on something long and hard and full of seamen, that would have been derogatory.

Now the Naval Air Squadron maintenance crews - those folks are classy. At least they're more classy since I got out anyway.
 
jtn said:
That's not derogatory. Now if you had said that submariners are stupid for wanting to go on a boat that sinks on purpose, or something about how they like to go down on something long and hard and full of seamen, that would have been derogatory.

Now the Naval Air Squadron maintenance crews - those folks are classy. At least they're more classy since I got out anyway.

Nothing like a sewer pipe sailor, a black shoe sailor and an airdale discussing NICK NAMES.

Calling a sailor a JARHEAD may cause some of

U ncle
S am's
M isguided
C hildren

to get a trifle upset.
 
Ok....Did I read the thread to fast? who voted other?


I have used Yellow (flashing) as runing but a warning condition


.
 
In our plant (printing) a flashing red indicator and buzzer means "about to start". A steady red means "running". A steady green means "stopped and safe". When I set the lamps and buzzers up I went by a corporate directive that is based on an ANSI code. I have it some where in my office at work. I'll try to remember to pull it out on Monday morning.
BTW- I'm proud to be called a jarhead, leatherneck, devil dog, teufelhunden, soldier of the sea, and all of the other various names given to Marines.
Bit of trivia for you. Know where the U.S.M.C. credits as being their birthplace? Tun Tavern, yep, a bar.
Did you know that the Marines is a part of the Department of the Navy? The men's department. Kidding squids. But it really is a part of the Navy.

Semper Fidelis
Dale
 
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