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circuit breaker "push to close" button color
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Author:  MattB [ Mon Feb 17, 2014 7:51 am ]
Post subject:  circuit breaker "push to close" button color

What are the standards that dictate what the red button does? Should it open a breaker or close a breaker? Does it depend on the voltage? Does it depend on the continent?

At low voltage:
Schneider Masterpact Circuit Breaker
open push button = red
close push button = black
http://static.schneider-electric.us/docs/Circuit%20Protection/0613CT0001.pdf

At medium voltage:
Schneider VR Vacuum Circuit Breaker
open push button = green
close push button = red
http://static.schneider-electric.us/docs/Circuit%20Protection/Medium%20Voltage%20Circuit%20Breakers/Type%20VR%20Circuit%20Breakers/6055-33.pdf

Author:  Larry Stutts [ Mon Feb 17, 2014 10:50 am ]
Post subject: 

Red generally means "Stop" or "Emergency Stop"

Author:  tim8282 [ Mon Feb 17, 2014 12:21 pm ]
Post subject: 

Matt- good catch, I would have thought that button colors would at least be the same for a manufacturers entire product line.

The only thing I can say is that IEC circuit breakers/switches typically use the color green to indicate "open" and red for "closed" with the logic being an open breaker is an electrically safe condition, red = hazardous. Some US breakers (SquareD QO, Cutler Hammer CHF) use a red or orange indicator to show that they are tripped in order for them to be spotted easier.

Maybe one of those breakers is sold internationally and the other is not? It's possible that one of the international standards calls out a requirement for button color which contradicts the US's standard practice (which would confirm your comment about continent).

Author:  JBD [ Mon Feb 17, 2014 2:09 pm ]
Post subject: 

tim8282 wrote:
Maybe one of those breakers is sold internationally and the other is not? It's possible that one of the international standards calls out a requirement for button color which contradicts the US's standard practice (which would confirm your comment about continent).


The 600V breaker with integral pushbuttons is an international design. The color black is associated with the symbol 1 meaning ON, the Red is the symbol 0 meaning OFF.

The medium voltage device is a breaker in an enclosure built to ANSI standards. It uses industrial pushbuttons which were probably chosen to mimic the colors of typical breaker control switches.

Medium voltage and 600V equipment have never had the same colors. The MV equipment followed utility color coding while the 600V followed industrial ones.

Author:  CSC [ Mon Feb 17, 2014 2:19 pm ]
Post subject: 

The confusion comes from what are used as "safety" colors, where green means SAFE and red means DANGER, as opposed to what we see every day while driving a car, where green is interpreted as GO and red means STOP. However, the traffic signal colors were misinterpreted, as a green light originally meant "safe to proceed" and a red light meant "dangerous to proceed", not GO and STOP. This improperly carried over into the electrical world, especially for electrical controls for operators, where green was used for RUN (i.e. GO) and red indicated STOP.

For electrical equipment, pushing a green button should render a safe condition (i.e. de-energized or OPEN or TRIP) and pushing a red button should initiate an unsafe condition (energizing a circuit or CLOSE). However, ANSI, UL, NEMA, etc. haven't come to a consensus on that yet, and probably never will, because the green = GO and red = STOP is in such widespread use. But that's just my opinion.

Author:  JBD [ Mon Feb 17, 2014 3:46 pm ]
Post subject: 

CSC wrote:
However, ANSI, UL, NEMA, etc. haven't come to a consensus on that yet, and probably never will, because the green = GO and red = STOP is in such widespread use. But that's just my opinion.

I agree, even though Red/Green color blindness is so predominant (about 8% of men).

Author:  PaulEngr [ Mon Feb 17, 2014 4:12 pm ]
Post subject: 

NFPA 79 defines green as on/run, and red as stop/off. I forgot where but I believe ANSI C37 series does the opposite. At this point it's pretty much an item to specify or ask but I've seen just about everything both ways. Generally something more akin to distribution or switchgear uses red for energized, while machine control tends to go more towards red meaning "off".

Author:  jdsmith [ Mon Feb 17, 2014 5:28 pm ]
Post subject: 

PaulEngr wrote:
NFPA 79 defines green as on/run, and red as stop/off. I forgot where but I believe ANSI C37 series does the opposite.



The IEEE Standard for Metal-clad Switchgear, C37.20.2, states
Quote:
7.19 Circuit breaker open/close position indication

Indicating lights shall be provided to indicate the open and closed positions of the circuit breaker. Unless
otherwise specified, the closed position shall be indicated by a red light and the open position by a green
light.


This being said, the two metal-enclosed switchgear standards (IEEE C37.20.1 and IEEE C37.20.3) do not have any requirement for the function of red or green lights, and do not even require indicating lights at all.

Author:  stevenal [ Tue Feb 18, 2014 9:59 am ]
Post subject: 

And in case anyone is interested, the "Green Light Club" is one you don't really want to join :)

Author:  David Castor [ Wed Feb 19, 2014 12:34 pm ]
Post subject: 

There is no standard in the US. Electric utilities almost universally use red to indicate a closed breaker or energized equipment and green to indicate open. At utility power plants this generally carries over to the low voltage equipment and process equipment (red indicates an open valve, green is a closed valve) In other industries, pushbutton colors and light colors vary. It is more important to be consistent within a particular facility.

Author:  scott hill [ Thu Feb 20, 2014 11:43 am ]
Post subject: 

Usually closing a breaker is done in a unrestricted time frame were you have plenty of time to read the instructions or consult someone familiar with the system . And opening a breaker alot of times is done in an emergency situation were all you have time to do is react. That`s why I prefere red for open because most people with little to no knowledge of an electrical system can relate 'red to stop'.

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