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Instruction Book
Page 22
Effective: May 2006
Figure 3-20 Replaceable Current Sensors Shown with
Bottom Adapters and Cover Plate Removed
Table 3.2 Magnum Current Sensors and Matching
Rating Plugs
Current Rating in Amperes
200
250
300
400
600
3-6.4 TRIP ACTUATOR
The trip actuator is a small cylindrically shaped electro-
magnetic device which acts mechanically to trip the cir-
cuit breaker (Figure 3-17). In general, it is comprised of
a permanent magnet, a spring loaded rod to produce
the mechanical tripping, and a lever for resetting the
actuator after tripping occurs. The electronic trip unit
provides a pulse which counteracts the effect of the per-
manent magnet, allowing the spring loaded rod to act
mechanically. The device is reset when the circuit
breaker opens.
3-6.5 MECHANICAL TRIP FLAG
A red, pop out mechanical trip indicator is an optional
Magnum DS/DSX/DSL feature. It is located above the
Toroidal
Sensor
800
2500
1000
3000
1200
3200
1600
4000
2000
5000
For more information visit: www.EatonElectrical.com
trip unit on the breaker's front faceplate (Figure 3-18). It
operates by releasing and popping out any time the cir-
cuit breaker trips due to to an overcurrent condition.
Note that the mechanical trip indicator will not prevent
the breaker from being reclosed. The indicator is reset
manually by pushing it back in. If the indicator is not
reset the circuit breaker will operate normally, but future
mechanical trip indication will be lost.
An optional overcurrent trip switch (bell alarm) that oper-
ates off the position of the mechanical trip indicator is
also available. The switch is reset when the trip indicator
is reset.
On optional Digitrip models with LED cause-of-trip indi-
cators, these indicators should also be reset (by pushing
momentarily) after the cause of the fault has been diag-
nosed; this will preserve the internal battery. On trip
units equipped for communication the LED reset func-
tion can be performed remotely using INCOM com-
mands.
3-6.6 MAKING CURRENT RELEASE
All Magnum DSDSX//DSL circuit breaker trip units have
a making current release function. This safety feature
prevents the circuit breaker from being closed and
latched on a faulted circuit. The non-adjustable release
is preset at a peak instantaneous current of 25 x I n ; this
corresponds to an rms current of 11 x I n with maximum
asymmetry.
The making current release is enabled only for the first 2
cycles following a circuit breaker closing operation. The
making current release will trip the circuit breaker
instantaneously, release the mechanical (pop-out) indi-
cator and flash the instantaneous LED trip indicator, if
so equipped.
3-6.7 HIGH INSTANTANEOUS TRIP OPTION
(MAGNUM DS ONLY)
The high instantaneous trip option is installed in 800 to
3200 ampere Magnum DS/DSX circuit breakers with a
100 kA interrupting capacity. In general, the high
instantaneous trip is comprised of three small air core
sensors, one in each phase, which produce a signal and
transmit it back to the trip unit when the 85 kA withstand
rating of the circuit breaker is exceeded. The result is an
instantaneous trip by the circuit breaker. This high
instantaneous trip option permits the 800-3200 ampere
Magnum DS circuit breakers to be applied where a 100
kA fault is possible, while selectivity up to 85 kA is main-
tained.
I.B. 2C12060H08
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