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Caution – Rockwell Automation 140U Q, M frame CB Electronic RMS Trip Unit installation and operation User Manual

Page 12

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If the system is a 4-wire system with a neutral current

sensor, apply the same current as described above
through one phase of the breaker, returning through the

neutral sensor, as shown in Fig.

breaker should

not trip, and the alarm indicator,

if supplied, should not

operate. Repeat the test on the other two phases.

If the system is a 3-wire system with no neutral current

sensor, apply the same current as described above
through any two phases of the breaker, with the connec-
tions exactly as shown in Fig. 14-3. The breaker should

not trip, and the alarm indicator,

if supplied, should not

operate. Repeat the test using the other two combinations
of breaker phases.

CAUTION

SHOULD BE USED FOR

AND NOT FIELD

CALIBRATION OF THE ELECTRONIC RMS GROUND

UNIT.

ANY TEMPORARY CONNECTION MADE

PURPOSE OF CONDUCTING TESTS SHOULD BE
RESTOREDTO PROPER OPERATING CONDITIONS
BEFORE

BREAKERTO SERVICE.

The results of the test are to be recorded on the test form

provided with the equipment.

7.0

RATING PLUG

The rating plug, as illustrated in Figure 15, is used to
establish the continuous ampere rating of the related
circuit breaker.

For adjustable rating plugs (Table 1

the primary

current carrying conductors used with the breaker must
be sized to correspond with the maximum setting of the

rating plug, in accordance with National Electric Code
requirements.

The Long Delay protection function of the trip unit is set at
the rating plug value

Short Delay and Instanta-

neous protection functions are set as a multiple of
Ground Fault protection function is independent of

Different rating plugs are available (Table 1-2) to match

the desired current rating and type of circuit breaker into
which the trip unit is to be installed.

Complete catalog descriptions of all available rating plugs
are given in the applicable circuit breaker supplementary
instruction leaflets (see Section 8.0).

8.0 REFERENCES

8.1 Q-Frame Molded Case Circuit Breakers

Frame Instruction Leaflet

Contact AB

8.2 Internal Accessories: The following types of internal
accessories, which mount on the trip unit, are available for

use. The number of the instruction leaflet covering the
installation of each accessory is shown.

Typical Time-Current Characteristic
curves for L Frame Breakers

.

Alarm

(ASL) Switch

...........

40752-076

.

Auxiliary Switch

...........................................

40752-074

.

....................................................

40752-075

Undervoltage Release Mechanism (Handle
Reset

...........................................................

40752-070

40752-072(2)

Effective 6/02

40752-078