I.L 40-100J
6
with the stationary contact resting against the back-
stop, the index mark is offset to the right of the "0"
mark by approximately .020". The placement of the
various time dial positions in line with the index mark
will give operating times as shown on the respective
time-current curves. For double trip relays, the follow
on the stationary contacts should be approximately
1/32".
7.2
Minimum Trip Current
The adjustment of the spring tension in setting the
minimum trip current value of the relay is most con-
veniently made with the damping magnet removed.
With the time dial set on "0", wind up the spiral spring
by means of the spring adjuster until approximately
6-3/4 convolutions show.
Set the .5-2.5 amp relay and all CO-2 relays on the
minimum tap setting. With the exception of CO-2 re-
lay, set the 1-2 amp relay on the 2 amp tap setting.
Set the 1-12 amp CO-2 on the 1 amp tap. Set time
dial position 6 on all relays.
Adjust the control spring tension no that the moving
contact will leave the backstop at tap value current
+1.0% and will return to the backstop at tap value
current -1.0%.
7.3
Time Curve Calibration
Install the permanent magnet. Apply the indicated
current per Table I for permanent magnet adjust-
ment (e.g. CO-8, 2 times tap value) and measure the
operating time. Adjust the permanent magnet keep-
er until the operating time corresponds to the value
of Table I.
For type CO-11 relay only, the 1.30 times tap value
operating time from the number 6 time dial position
is 54.9
±
5% seconds. It is important that the 1.30
times tap value current be maintained accurately.
The maintaining of this current accurately is neces-
sary because of the steepness of the slope of the
time-current characteristic (Figure 16). A slight vari-
ation,
±
1%, in the 1.3 times tap value current (includ-
ing measuring instrument deviation) will change the
timing tolerance to _ 10% and the effect of different
taps can make the total variations appear to be
±
15%. If the operating time at 1.3 times tap value is
not within these limits, a minor adjustment of the
control spring will give the correct operating time
without any undue effect on the minimum pick-up of
the relay. This check is to be made after the 2 times
tap value adjustment has been made.
Apply the indicated current per Table I for the elec-
tromagnet plug adjustment (e.g. CO-8, 20 times tap
value) and measure the operating time. Adjust the
proper plug until the operating time corresponds to
the value in Table I. (Withdrawing the left hand plug,
front view, increases the operation time withdrawing
the right hand plug, front view, decreases the time.).
In adjusting the plugs, one plug should be screwed
in completely and the other plug run in or out until the
proper operating time has been obtained.
Recheck the permanent magnet adjustment. If the
operating time for this calibration point has changed,
readjust the permanent magnet and then recheck
the electromagnet plug adjustment.
7.4
Indicating Contactor Switch (ICS)
Close the main relay contacts and pass sufficient dc
current through the trip circuit to close the contacts
of the ICS. This value of current should be not great-
er than the particular ICS tap setting being used. The
operation indicator target should drop freely.
For proper contact adjustment, insert a .030" feeler
guage between the core pin and the armature. Hold
the armature closed against the core pin and guage
and adjust the stationary contacts such that they just
make with the moving contact. Both stationary con-
tacts should make at approximately the same time.
The contact follow will be approximately 1/64" to 3/
64".
7.5
ac Auxiliary Switch (ACS)
The core screw must be adjusted to the value of
pickup current desired. The nameplate data of the
ACS will furnish the actual current range that may be
obtained from the ACS unit.
7.6
Indicating Instantaneous Trip Unit (IIT)
The proper tap must be selected and the core screw
adjusted tothe value of pickup currentdesired.
The nameplate data and tap plate of the IIT will fur-
nish the actual current range that may be obtained
from the IIT unit.
