Effective 11/2003
Page 34
I.L. 66A7535H02
Suitable
Conductors
Low-Voltage
ac Current
Source
A
B
C
Polarity &
Identification
Figure 5.3 Connection Details to verify a trip (Ground)
Suitable
Conductors
A
B
C
Polarity &
Identification
Shorting
Conductors
Low-Voltage
ac Current
Source
Figure 5.4 Connection Details to verify Sensor Polarities
TEST 4. Connect primary current circuit such that two
circuit breaker poles
(See Figure 5.4)
are in series and
ramp current up to 40% of plug rating. The circuit breaker
should not trip. If the CH Type-V current sensor’s polarities
are incorrectly wired, the circuit breaker will trip out on
ground fault at about 20%. If a ground fault trip occurs,
check secondary wiring of CH Type-V current sensors for
proper polarity.
Note:
For circuit breakers with 100A thru 400A sensors the
Ground Fault Setting
could be raised or turned
OFF
and
additional “Long Time” or “Short Time” tests could be
conducted. Adjusting the
Long Delay Setting
to 0.4x would
help to minimize the current requirements to simulate to
overload levels.
5.3.2.2 Secondary Injection Testing
If desired, further testing can be done by injecting test
current across the CH Type-V current sensor’s output
terminal screws or injecting directly into the circuit
breaker’s secondary contacts (A-4, A-19) or (A-5, A-20) or
(A-6, A-21)
(See Figures 1.5 and 5.5)
Note:
If the circuit breaker is out of the cell, it may be
beneficial to make a test harness.
The test harness will
have female AMP sockets (#66598-2) in one housing on
the one end. The other should consist of spade
terminations that connect to the
5A
and
Common
posts on
the MS-2 current source.
An inductor (Signal Transformer CL-1-2) or 25 ohm resistor
should be placed in series with the red terminal post to
stablize the output for currents less than 1.5 amperes.
Attach the separate True RMS ammeter in series with this
component. The rest of the wiring is direct to the phase
input secondary contacts.
Connect the Auxilary Power Module to the Digitrip 1150’s
upper right hand corner connector.
Hook up a circuit breaker
Auxiliary Switch
to the MS-2
tester’s
Contacts
terminals to stop the clock and the
source of current.
Test Procedure:
Jumper B-6 to B-7 to temporarily defeat Ground Fault.
TEST 1. Turn power switch
ON
and ramp up current
slowly to about 30% (0.3A). Enter the Meter Menu and
verify current value is 30% of rating plug amperes.
TEST 2. Keep increasing current and note where the
flashing
Unit Status
LED is about four times faster. This
point is the “Long Delay Pickup Point” and is nominally
1.1x
Long Delay
Setting
(1.1A).
TEST 3. Repeat Test 1 and 2 for other two inputs.
TEST 4. Set the current to 300% which is 3A (+/- 0.1).
Remove or short out the series resistor for the trip tests.
NOTE:
Three Amperes is truly 300% only when the
Long
Delay Setting
is set to 1x. Other 300% test current levels
will need to be calculated if the
Long Delay Setting
is set
other than 1x. Set
Ground Setting
to
OFF,
Instantaneous
to 4x and
Short Delay
Setting
to 8x.