Why "Shunt trip" breaker?

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iwire

iwire

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Open Neutral said:
But it isn't.... The coil is in series with the [ STOP button] contacts and the supply voltage...
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We are not talking electrically in series or parallel. We are talking mechanically in parallel.

The mechanical action of the solenoid is in parallel with the mechanical action of the standard trip mechanism.
 
mbrooke

mbrooke

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iwire said:
That's dangerously close to the ground up vs ground down or Chevy vs Ford type topics. :D

If we start debating that I am going to move it into its own thread.
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Not meant to debate, just to point out that what we may call something doesn't always reflect the literal definition of said name :thumbsup:
 
G

GoldDigger

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Another way of looking at it is that you can trip the breaker by shunting (diverting) a small amount of current around it.
Not only are we not sure of the origin yet, we are not even sure which dictionary entry for shunt was part of the origin.
 
ATSman

ATSman

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Open Neutral said:
But it isn't.... The coil is in series with the [ STOP button] contacts and the supply voltage...
Click to expand...

When they say "in parallel with other tripping functions" they mean that typically a small breaker has (3) ways of
automatically tripping open: Trip Unit [1. Long Delay: sustained overload, like 300% rating 2. Instantaneous: short circuit, like >1000% rating] Shunt Trip, solenoid energized by an external voltage source. On large power breakers, LV, MV & HV class, other trip unit functions exist such as Short Time, Ground Fault, Isq T, etc for system coordination.
"Tripping" is usually referred to as the automatic opening as apposed to the manually opening by operating the breaker handle to off.
 
F

Fnewman

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From Schneider Elecrtric

From Schneider Elecrtric

: A shunt trip device is an optional accessory in a circuit breaker that mechanically trips the breaker when power is applied to the shunt trip terminals. The power for the shunt trip does not come from within the breaker, so it must be supplied from an external source.
 
Tony S

Tony S

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Resting under the Major Oak UK
Various shunt trips in a MG M-Pack 1000A ACB.

M-Pack-shunttrips_zps7xv3cr5r.jpg


Watch out if UV coils are fitted, they get very hot and can burn the skin.
 
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