Substation Trip versus Open nomenclature 1

[RSChinn]

In our substations there is mixed nomenclature,including nameplates, over our control switches and pushbuttons. Sometimes it say "Open" and other times it says "Trip". Does anyone have a code, standard, or utility practice on a this? We haven't thought this was a big deal, but somebody questioned it so I thought I would ask it in this forum. Thanks.

 

[patrick7961]

open is an action done by a person. does not matter if the person is standing at the breaker, in the control building or in teh dispatch center.

trip is an action initiated by a relay for any reason, could be transfer trip, breaker failure trip, overcurrent trip, ect.

 

[patrick7961]

at least that is the standard if you will that the utility that i worked at followed.

sorry for the double post..

 

[jghrist]

open is an action done by a person. does not matter if the person is standing at the breaker, in the control building or in teh dispatch center.

trip is an action initiated by a relay for any reason, could be transfer trip, breaker failure trip, overcurrent trip, ect.

But then why do most manual control switches in the USA say "Trip" instead of "Open"? Look at all of the photos and diagrams of breaker control switches in the Electroswitch catalog.

I would say Trip for any operation that energizes a "Trip" coil to open a device. This would cover any electrical opening of a circuit breaker.

Breakers are tripped, switches are opened.

 

[ScottyUK]

Breakers are tripped, switches and disconnectors are opened.

jghrist beat me to it.


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If we learn from our mistakes I'm getting a great education!

 

[Zogzog]

But after the breaker is tripped the position indicator says "Open", not "Tripped".

"Trip" refers to a device for tripping a mechanism.
"Tripping" means to release or be released as a catch or trigger.

So when you push the "trip" button, or move the remote actuator to the "trip" position, or a relays sends a "trip" signal, they all do the same thing, rotate the "trip" bar, witch moves the "trip" latch, which releases the "trip" springs (the energy has now been released), which "Opens" the breaker.

So breakers are opened, springs are tripped. Ta Da!!!

Switches have no catches or triggers hence the absense of the term "trip" for switches.

 

[slavag]

Oh English man :-(.
Please decide it for us, non-English.
Our rules are very simple: what patrick7961 and Zogzog saied.
Trip is function of protection ot another system, is command.
Open command is handle operation. Open is position/indication

 

[jghrist]

Oh English man .
Please decide it for us, non-English.
Our rules are very simple: what patrick7961 and Zogzog saied.
Trip is function of protection ot another system, is command.
Open command is handle operation. Open is position/indication

Yeah, yeah! Then explain why all of your switches say I and O.

 

[slavag]

:-( I don't know :-(

O-open?
I-insert?

 

[PHovnanian]

Hmm. In my home electrical panel, "Trip" and "Open" are distinct handle positions indicating the outcome of different actions. I can open the breaker, but the overcurrent function trips it.

I've seen the same confusion at several utilities, so I'm not certain if there's an industry standard (or perhaps they aren't following it). I've overheard radio conversations between service personnel and the system operators:

"Check the breaker position."

"Its tripped."

"Is there a relay target visible?"

"No. The handle was placed in the 'open' position."

 

[msb10]

I'm pretty sure the "I" and "O" are really the number "1" and the number "0"; the number 1 represents "on" and the number 0 represents off.

Regards,

Matt

 

[Zogzog]

There are 10 types of people in the world, those that understand binary and those that don't.

 

[rbulsara]

This is just my view and opinion.

Manually tripping a breaker is functionally (electrically) same as manually opening a breaker. That is the intent was to open a breaker after all. Also "Open" goes well with the label for the opposite action of closing the breaker as "Close". I personally prefer labeling the remote breaker control switch positions as "Open"/"Close". It is very common to write in switching procedures as "Close the breaker or Open the breaker".

Trip is generally associated with automatic tripping of the breaker on a fault by relay or a trip unit. I do not recall seeing "Trip" as the switch control label in the USA, that does not mean that it does not exist.

 

[Zogzog]

The pistol grip switches all seem to say open, but most pushbuttons on the breaker say "Trip" or "Push to Trip"

IMO this is because your are tripping the springs, the springs open the breaker, as I posted earlier.

I did some real research on my ealier post, I think it is correct.

 

[rbulsara]

zogzog:

that also reminds me, the push button that are labeled as "trip" or "Push to trip" such as one that you posted the picture of, are intended to be used during a test or some kind of emergency conditions. Even the PB intended for "normal" opening functions are still labeled Open. For example all PBs on the LV power CBs.

On MCCB's the almost hidden "Trip" push button are included to simulate a "trip" condition and breakers "tripped" using that requires a "reset" before closing.

 

[jghrist]

See page 11 (.pdf page 12) of the Electroswitch Series 24 control switch publication

http://www.electroswitch.com/electroswitchesandrelays/technical_publications/24_1.pdf

Standard nameplates for Series 24 breaker control switches say "Trip".

 

[rbulsara]

jghrist:

Refer to page 7 (midway on right) of your link. It lists the labels one can have. Both Open-Close and Trip-Close are available. There is no so called "standard". I have used and specified a lot of these switches. Mfrs. will provide what is specified. (if specified).

I personally associate Trip action with something that would require a reset to reclose.

 

[dpc]

Questions similar to this (red light vs green light) come up fairly frequently. At least in the US, there is no one standard that covers things like this, only customary practices that vary from industry to industry and region to region.





"Theory is when you know all and nothing works. Practice is when all works and nobody knows why. In this case we have put together theory and practice: nothing works... and nobody knows why! (Albert Einstein)

 

[PHovnanian]

Questions similar to this (red light vs green light) come up fairly frequently. At least in the US, there is no one standard
that covers things like this, only customary practices that vary from industry to industry and region to region.

Oh now you've gone and done it! Try getting the lid back on that can or worms.

I've sat in on far too many safety meetings where the operators and other personnel argue the meanings of red vs green and open vs closed when they have to deal with both valves (fluid/steam flow) and electrical system status.

 

[Zogzog]

"For example all PBs on the LV power CBs."

Most of those say trip too.

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