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I.L 40-100J
5.2
Instantaneous Reclosing
The factory adjustment of the CO unit contacts pro-
vides a contact follow. Where circuit breaker reclos-
ing will be initiated immediately after a trip by the CO
contact, the time of the opening of the contacts
should be a minimum. This condition is obtained by
loosening the stationary contact mounting screw, re-
moving the contact plate and then replacing the
plate with the bent end resting against the contact
spring.
For double trip relays, the upper stationary contact is
adjusted such that the contact spring rests solidly
against the back stop. The lower stationary contact
is then adjusted such that both stationary contacts
make contacts simultaneously with their respective
moving contact.
5.3
Indicating Contactor Switch (ICS)
The only setting required on the ICS unit is the selec-
tion of the 0.2 or 2.0 amperes tap setting. This selec-
tion is made by connecting the lead located in front
of the tap block to the desired setting by means of
the connecting screw.
When the relay energizes a 125 or 250 volt dc type
WL relay switch, or equivalent, use the 0.2 ampere
tap; for 48 volt dc applications, use the 2.0 ampere
tap and use a type WL relay with a Style
#304C209G01 coil, or equivalent. The relay is
shipped set for 2.0 tap.
5.4
Indicating Instantaneous Trip (IIT)
The IIT setting is the level of ac current at which it will
pickup. It should be set to coordinate with other de-
vices so it will never operate for a fault in a protective
zone where tripping should be produced by other de-
vices. The transient reach will not exceed 130% for
an 80o circuit angle or 108% for a 60o circuit.
The proper tap must be selected and the core screw
must be adjusted to the value of pick-up current de-
sired.
The nameplate data will furnish the actual current
range that may be obtained from the IIT unit. It is rec-
ommended that the IIT be set on the higher tap
where there is a choice of tap settings. For example,,
for a 20 amperes setting use the 20 to 40 tap rather
than the 6 to 20 tap.
4
Courtesy of NationalSwitchgear.com
5.5
ac Auxiliary Switch (ACS)
The core screw must be adjusted to the value of
pickup current desired.
6.
ADJUSTMENTS & MAINTENANCE
The proper adjustments to insure correct operation
of this relay have been made at the factory. Upon re-
ceipt of the relay no customer adjustments, other
than those covered under "SETTINGS" should be
required.
For relays which include an indicating instantaneous
trip unit (IIT), the junction of the induction and indi-
cating instantaneous trip coils is brought out to
switch jaw #3. With this arrangement the overcurrent
units can be tested separately.
Performance Check
The following check is recommended to verify that
the relay is in proper working order:
6.1
Contact
The index mark on the movement frame will coincide
with the "0" mark on the time dial when the stationary
contact has moved through approximately one-half
of its normal deflection. Therefore, with the station-
ary contact resting against the backstop, the index
mark is offset to the right of the "0" mark by approxi-
mately .020". The placement of the various time dial
positions in line with the index mark will give operat-
ing times as shown on the respective time-current
curves. For double trip relays, the follow on the sta-
tionary contacts should be approximately 1/32".
6.2
Minimum Trip Current
Set the time dial to position 6 using the lowest tap
setting, alternately apply tap value current plus 3%
and tap value current minus 3%. The moving con-
tacts should leave the backstop at tap value current
plus 3% and should return to the backstop at tap val-
ue current minus 3%.
6.3
Time Curve
Table I shows the time curve calibration points for
the various types of relays. With the time dial set to
the indicated position apply the currents specified by
Table I, (e.g. for the CO-8, 2 and 20 times tap value
current) and measure the operating time of the relay.
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