Red for on or green for on

[akreel]

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.

Most operators hate change. Determine the existing plant convention (whatever it may be) and you'll hear a lot less griping.

 

[burnerman]

Surely it is a dodgy practice to rely on an indicator lamp to signal whether or not a plant is safe to the operator.

A plant is made safe by designing it such that no access can be obtained to moving/hot/energised parts, etc, by correct use of guarding, interlocks and lock-off systems.

Therefore ask yourself what is the purpose of the indicator lamp? I would have thought that it is to inform the operator that the process is doing what it's supposed to (or not as the case may be).

That being so then it is intuitive that green signals that things are ok. I prefer to have flashing lights for things that require operator attention - red for faults and amber (or other colours) to signal that further action is required. Having said that I'm not too concerned about colours - correct labelling and operator training are far more important - besides, what about colour blind operators and the old panels where any old lens or lamp will do to replace a broken one?

 

[CaseyK]

Well, its after midnight, I'm tired and cranky.....

We could pull off all the lenses, put them in a box, then grab one out at a time, and put it on the next lamp. No standards, no consistancy. Wait, I've seen that in some factories.

OR

We could take off all the lenses, put them in a box, then throw them away. Then they have to read the nameplate above the lights. That is, if they have them.....

As I said, I'm tired and cranky.....

Hope everyone has a GREAT WEEKEND!!!

regards.....kc

 

[bala_mk]

Hi

Red for ON and Green for OFF is purely applicable for electral side that why all the breaker manufacturers show the ON signal in RED and OFF signal in GREEN,while working with high voltage this is very inportant,even if you look in to a feeder the same wiil reflects coz there will be high voltage for running your equipment and this code is for the people who work in electrical

while coming to HMI the operators are not the persons who directly interact with the feeders or the equipment that's why there are given like GREEN for ON and RED for OFF,and there wont be any danger if they touch the softkeys given

bala murali

 

[parky]

Hmmm. came across this some years ago it wasn't brit steel was it?

they use that spec on some plants.

 

[Chuck Woodbury]

Green is go. On the Ballast Control Panel on Submarines a green board means it is okay to dive the boat. I always use green for run and red for not running. AB does it the other way around but no one in Milwaukee could give a good reason for it.

 

[rsdoran]

Onct upon a time I had the bright idea of trying to get a GLOBALLY accepted standard developed for just this purpose.
http://www.plctalk.net/qanda/showthread.php?t=12320&highlight=standard

As you can see the idea was not cordially accepted.

I use NFPA 79 Electrical Standard for Industrial Machinery, 2002 edition.
http://www.nfpa.org/catalog/product.asp?category%5Fname=Electrical+Safety&pid=7902&target%5Fpid=7902&src%5Fpid=&link%5Ftype=category&src=catalog

I still think it would be a good idea if we could combine things like NEC, CEC, IEC etc where they provide the same standard. They are working on that but its going to take time.

BTW: OSHA has developed an alliance with NFPA, ANSI and others. The electrical standards are being left up to NFPA but I am not sure of all the details. I think some of the older standards like NEMA, JIC, and possibly ANSI too, have been replaced by NFPA.

 

[Gerry M]

I still think it would be a good idea if we could combine things like NEC, CEC, IEC etc where they provide the same standard. They are working on that but its going to take time.

That statement sums up the whole thing.

If people have difficulty agreeing on something simple like red and green then it will definitely take time, and lots of it.