Effective July 2010
Instructional Leaflet
IL8700C39-04
Installed
pick-up (Dial) setting
rating
amperes
j
plug
amperes a
k
B
k
C
k
D
k
E
k
f
h
k
(In)
100
25
30
35
40
50
60
75
100
200
50
60
70
80
100
120
150
200
250
63
75
88
100
125
150
188
250
300
75
90
105
120
150
180
225
300
400
100 120
140
160
200
240
300
400
600
150 180
210
240
300
360
450
600
800
200 240
280
320
400
480
600
800
1000
250 300
350
400
500
600
750
1000
1200
300 360
420
480
600
720
900
1200
1600
400 480
560
640
800
960 1200 1200
2000
500 600
700
800
1000 1200 1200 1200
2400
600 720
840
960
1200 1200 1200 1200
3200
800 960 1120 1200 1200 1200 1200 1200
4000 1000 1200 1200 1200 1200 1200 1200 1200
5000 1200 1200 1200 1200 1200 1200 1200 1200
j
Except as noted, tolerances on pick-up levels are ±10% of values
shown in chart.
k
Ground fault pick-up levels shown are nominal values when
tested with external control power present. Without external con-
trol power, such as is the case with the Digitrip RMS 510, ground
pick-up levels may exceed these values and be as high as the
value shown for the “E” setting of that particular rating plug.
l
Not applicable to Digitrip OPTIM. The ground fault pick-up setting
is read directly from Digitrip OPTIM. These settings range from
25% to 100% of the rating plug value up to a maximum NEC
limitation of 1200 amperes.
Depending upon the installation requirements, alternate
ground fault sensing schemes may be employed. Two
popular methods include: Ground return and zero sequence.
Either method can be employed with the Digitrip Trip Unit.
For either type application, a ring type current sensor, as il-
lustrated in Figure 7, is normally employed. For ground return
sensing, the sensor is arranged to have the system “main
bonding jumper” pass directly through the sensor. For zero
sequence sensing methods, all phase and neutral conduc-
tors must pass through the sensor.
Where multi-conductor cables are required for a particular
circuit and the window opening in a single BYZ sensor is too
small to accommodate all cables, separate BYZ sensors may
be installed on each set of cables
(3 phase, neutral) and the secondaries connected in paral-
lel. (Note: Proper polarity markings must be observed.) The
resultant secondary current signal will be equivalent to a
single BYZ sensor.
The BYZ current sensor styles shown in Figure 7 are avail-
able for all previously mentioned applications. When either
style sensor is used, the ground fault values shown in Table
3 are not applicable and the values shown in Table 4 should
be used. One of the reasons for using the BYZ current
sensors is to improve the level of sensitivity. This being the
case, then the ground fault functional pick-up setting should
be placed on position “A.” The sensitivity of the ground ele-
ment for this kind of arrangement will depend upon the ratio
of the BYZ sensor used.
A variety of utilization schemes are available utilizing each of
the above methods of ground fault sensing. Therefore, the
individual installation requirements must be closely studied
to insure proper application.
5.5 Current Sensors
The three current sensors installed in the circuit breaker are
located at the rear of the circuit breaker on the lower studs.
The location is shown in Figure 3-1 of l.B. 694C694. They
produce an output signal proportional to the load current
and furnish the Digitrip Trip Assembly with the intelligence
and energy to trip the circuit breaker when the time-current
conditions exceed the functional protection settings.
The continuous current rating for any frame size breaker can
be changed by changing the rating plug. A complete tabula-
tion of available current sensors and rating plugs is given in
ratings sensor ratings - amperes
plug
amps 200 300 400 600 800 1200 1600 2000 2400 3200 4000 5000
100 6.3
200 12.5 8.3 6.3
250
10.4 7.8
300
12.5 9.4 6.3
400
12.5 8.3 6.3
600
12.5 9.4 6.3
800
12.5 8.3 6.3
1000
10.4 7.8 6.3
1200
12.5 9.4 7.5 6.3
1600
12.5 10 8.3 6.3
2000
12.5 10.4 7.8 6.3
2400
12.5 9.4 7.5
3200
12.5 10 8.0
4000
12.5 10.0
5000
12.5
j
Except as noted, tolerances on pick-up levels are ±10% of values
shown in chart.
k
Ground fault pick-up levels shown are nominal values when
tested with external control power present. Without external
control power such as is the case with the Digitrip RMS 510 trip
unit, ground pick-up levels can vary between the minimum and
maximum values shown for each sensor rating.
l
For BYZ (100/5) sensor, multiply above values by two.
14
eaTOn CORPORaTIOn
www.eaton.com
Table 3 Ground Current Pick-up Settings
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Table 4 Approximate Ground Fault Pick-up Amperes Using BYZ
(50/5) Sensor and “A” Position Setting on Ground Fault Pick-up
j
k
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Summary of Contents for Digitrip RMS Series
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