Rating Plug; 3-6.3 Current Sensors - Eaton MDN-408 Instructions For Installation, Operation And Maintenance

3-6.2 RATING PLUG

All Magnum DS/DSX/DSL circuit breaker trip units use a
fixed type rating plug. The current rating of the rating
plug must match the current rating of the integrally
mounted current sensors (Figure 2-3, 3-18 and Table
3.2). 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.
3) The National Electrical Code (NEC) requires that the
maximum ground fault pickup value not exceed 1200
amperes. A properly matched rating plug accomplishes
this requirement for higher ampere sensors by incorpo-
rating circuitry to identify that level by 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 3.2 for a tabulation of the available rating
plugs.

3-6.3 CURRENT SENSORS

Three toroidally wound current sensors are installed at
the rear of the circuit breaker on the lower terminals
(Figure 3-20). The sensors produce an output current
proportional to the load current. Under preselected con-
ditions of current magnitude and time, the sensors fur-
nish 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.
Refer to Table 3.2 for a tabulation of the available cur-
rent sensor ratings.
I.B. 2C12060H08
Figure 3-18 Digitrip RMS 1150 Programmable Trip Unit
Installed in Magnum DS Circuit Breaker
Figure 3-19 Hand Held Tester
For more information visit: www.EatonElectrical.com
Instruction Book
Effective: May 2006
Pop Out
Pop Out
Trip Flag
Trip Flag
Auxiliary Power
Auxiliary Power
Module Port
Module Port
Rating
Rating
Plug
Plug
Test Test
Receptacle
Receptacle
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