MCC run, ready light

[cmelguet]

Hi,

Anyone know an standard that define the colours in the lights on LV MCC modules. I mean the lights that indicate Runnign status, ready status, and fault.

Regards,

 

[LionelHutz]

Where are you?

Around here, red and green are used for stopped and running, some places use green for running and others use red for running. Amber is generally for faults.

 

[jraef]

You have fallen down the rabbit hole. The Cheshire Cat awaits you with a grin...

It is a never ending debate to which there is no definitive answer, including on the concept of whether or not there IS a definitive answer. The "Stoplight" convention (Green = Go, Red = Stop) is equally valid to some people, whereas the "Industrial Safety" convention (Red = On / Dangerous, Green = Off / Safe) is the only one worth considering to others yet is itself often considered "dangerous" by those who adopt the Stoplight convention (and vice versa).

One issue that I think causes some of the confusion is the aspect of color definitions for Push Buttons getting inappropriately (in my opinion mixed in with indicator light colors. In the Industrial Safety convention and most other standards I've seen, a Green PB = Start, a Red PB = Stop. So many people translate that over to the indicators, which then becomes the Stoplight convention.

In general, Amber / Yellow is most often used for a Fault indication, but then there are those who make up their own scheme: I am working on one right now that is White for Ready, Green for Running, Blue for Off and Red for Fault (I think it's nuts myself, but I'm not the design engineer).

There are probably more "standards" that support the Industrial Safety convention, but then there are standards that support the Stoplight convention or having no definitive answer as long as it is well defined and understood in a facility.

Probably not what you wanted to hear though...

"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> faq731-376

 

[micksouth]

Hello Mate,
I think most people would agree an emergency stop is invariably red in colour.
Therefore, a 'normal' stop push button is normally red (in the UK at least).
When an engineer walks into a plantroom and sees all green lights he assumes all is ok and operating normally.
If he sees a red light, this will subconsciously attract his attention(as does a red stop traffic light or a red warning sign etc).
Hope this helps.
p.s. a red light in Amsterdam means something entirely different!

 

[ScottyUK]

Mick,

Over there it's the blue lights you need to watch out for. And I don't mean the ones on the top of the police cars!

 

[davidbeach]

Red lights mean all is well. It's green lights that signify trouble. Transforming a substation full of red lights into station full of green lights results in lots of 'splaining.

 

[GTstartup]

Agreed - Red is pump running/breaker closed/valve open. Green Pump Off/breaker opened/valve closed. I normally see white lights on the MCC to indicate that the control circuit is good/not tripped.

 

[jraef]

Aaaaaand, the rabbit hole goes deeper...

"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> faq731-376

 

[DRWeig]

It's a deep rabbit hole, jraef.

I don't know of a standard, either.

Old Square-D and newer Schneider/Square-D low-voltage switchboards with integral control of a backup generator have:

White = ready
Yellow = trouble (can still operate transfer apparatus manually)
Red = breaker closed (source connected to bus)
Green = breaker open (source disconnected from bus)
Blue = fault (both breakers disconnected, fixing needed)

For manual operation of the breakers, though, black = close, red = open



Good on ya,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies

 

[ScusaMe]

In the USA, there's NFPA 79 Electrical Standard for Industrial Machinery.
In the 2012 edition, see Section 10.3 Indicator Lights and Icons of Color Graphic Interface Devices and Table 10.3.2 Machine Indicator Lights and Icons.

 

[jraef]

Table 10.3.2 Machine Indicator Lights and Icons (paraphrased)
RED = Danger / Emergency / Faulty
YELLOW (AMBER) = Warning(Caution) / Abnormal
GREEN = Safe / Normal
BLUE = Mandatory action
CLEAR / WHITE = No specific meaning assigned

So I know how I interpret this, Red = Running, Green = Off. But the argument I always hear, is running "Danger" or is Running "Normal"? I understand that this may seem irrational to those that think like I do, yet those who believe the other way say that WE are equally irrational!

"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> faq731-376

 

[ScusaMe]

Jeff,

Consider that the antipode of SAFE is DANGER ... and set your mind at ease.

" It was ever thus. " <g>