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Instruction Book
Page 46
Effective: May 2016
5-5.2 RATING PLUG
All trip units use a fixed type rating plug. The current
rating of the rating plug must match the current rating of
the current sensors (Figure 3-9
The rating plug performs several functions:
1. It tells the trip unit what the rating is of the current
sensors. A label on the front of the rating plug clearly
indicates that the rating plug and sensors must have the
same rating.
2. It determines the maximum instantaneous setting
which is a function of the current sensor rating.
If the rating plug is removed from the trip unit, the circuit
breaker will trip if it is carrying current. Make certain the
rating plug is secured in position with its retaining screw.
Do not torque the retaining screw beyond 15 In-Oz.
Refer to Table 5.2 for a tabulation of the available rating
plugs.
5-5.3 CURRENT SENSORS
Three current sensors are installed at the rear of the
cassette on the lower terminals. The sensors produce
an output current proportional to the load current. Under
preselected conditions of current magnitude and time, the
sensors furnish the trip unit with a signal and the energy
required to trip the circuit breaker.
Neutral current sensors are available for customer
installation. The additional sensor is not supplied with
the circuit breaker and must be ordered separately.
They are wired to the trip unit through the secondary
contacts of the circuit breaker.
Zero sequence transformers (vectorial summation) are
available with a 100:1 and 200:1 tap ratio.
Refer to Table 5.2 for a tabulation of the available cur-
rent sensor ratings.
Table 5.2 Current Sensors and Matching Rating Plugs
Current Rating in Amperes
100
300
6 3 0
1200
5-18 and Table 5.2).
,
200
250
400
600
800
1000
1250
1600
For more information visit:
5-5.4 CIRCUIT BREAKER CONTROLLER
The trip unit is wired to the circuit breaker's controller.
Under pre-selected conditions, the controller receives
a pulse from the trip unit and the controller trips the
circuit breaker.
www.Eaton.com
IB131017EN
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