What is the difference between circuit breaker auxiliary switches S1, S2, S3, S4 etc.?

[electrical429]

On high voltage circuit breaker schematics there are circuit breaker auxiliary switches S1, S2, S3, S4. All can be normally open, normally closed, late break, early make. But what is the difference between them? The only explanation that I have found anywhere states the following:

Auxiliary circuit component in circuit breaker:
S1 - Auxiliary switch on mechanism
S2 - Auxiliary switch on block magnet -Y1
S3,S4,S5 - Auxiliary switch on switch shaft
S7 - Fleeting contact ≥ 30 ms for c.b.

Auxiliary circuit component in truck:
S8 - Limit switch test position
S9 - Limit switch service position

That doesn't really tell me a lot. I assume S8 changes its state when CB truck is in test position? And S9 when CB truck is in service position? But what about S1-S7? If I need to use aux. switches for indication, tripping, blocking, interlocking - can I use any of the S1-S7 switches? I need normally open aux. switch when CB is closed and normally closed switch when CB is open.

 

[cranky108]

You will need a mechanical diagram to show you when each operates during the open and close cycles.

 

[electrical429]

Without mechanical diagram can you explain S1 and S2 switches only? Or at least tell me which one can be used for indication, tripping, blocking, interlocking?

 

[cranky108]

Unless they are labeled something like 52a, or 52b, or older terms like 52aa, etc, no I can't tell you.

 

[bacon4life]

I have never seen standardization of auxiliary switch labeling for S1, S2, etc. Each specific breaker model may use each auxiliary switch for a different purpose.

 

[crshears]

What cranky and bacon said; without device function numbers, it's anybody's guess . . . and speaking only for myself, if this a company you are only just starting to deal with, and if this is the way they do things, IMHO you might be very well advised to just walk away.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[Sn00ze]

I've seen Iljin and siemens use the S1,S2,ETC designation for their auxiliary relays.

@electrical429, these are just arbitrary letters chosen by manufacturer for their devices (usually). without context (in this forum) they are almost meaningless.

What you need to do is look up the device function/designation table which could also be in your BOM for the equipment and see what each is assigned for.