TYPE BL-1 RELAY
LL. 41-553.2B
The vertical edge setting may be set for a larger
contact gap but should not be set for more than six
minor divisions if the break contacts are to be in a
closed position at full load.
External diagram in Fig. 9 show several com-
binations for applying these units.
ADJUSTMENT & MAINTENANCE
The proper adjustments to insure correct
operation of this relay have been made at the fac-
tory. Upon receipt of the relay no customer ad-
justments, other than those covered under
“SETTINGS” should be required.
ROUTINE MAINTENANCE
All relays should be inspected and checked
once a year or at other time intervals as dictated by
experience to assure proper operation. Generally a
visual inspection should call attention to any
noticeable changes. A minimum suggested check
on the relay system is to close the contacts manual-
ly to assure that the breaker trips and the target
drops. If an additional time check is desired, pass
test current through the relay and check the time
of operation.
All contacts should be periodically cleaned. A
contact burnisher #182A836HOl is recommended
for this purpose. The use of abrasive material for
cleaning contacts is not recommended, because of
the danger of embedding small particles in the face
of the soft silver and thus impairing the contact.
ACCEPTANCE CHECK
AND
CALIBRATION
ICS ACCEPTANCE CHECK
Refer to test diagram shown in Fig. IO.
Connect an adjustable dc current source to relay
terminal 4 as shown with a jumper type connection
made inside the relay. Connect the jumper to the
right hand (facing the front of the relay) stationary
contact of the ICS located in the lower right posi-
tion.
Close switch S1 and pass sufficient dc current
through the trip circuit to close the contacts of the
ICS. This value of current should not be greater
than the particular ICS nameplate rating. The in-
dicator target should drop freely.
Repeat above except to pass 85% of ICS
nameplate rating current. Contacts should not
pick up and target should not drop. Open switch
S1 when checking is completed.
ICS
CALIBRATION
Use the following procedure for calibrating the
relay if the relay has been taken apart for repairs
or the adjustment have been disturbed. This
procedure should not be used unless it is apparent
that the relay is not in proper working order. (See
“Acceptance Check”).
Initially adjust unit on the pedestal so that ar-
mature lingers do not touch the yoke in the reset
position. This can be done by loosening the moun-
ting screw in the molded pedestal and moving the
ICS in the downward position.
1. Contact Wipe: Adjust the stationary con-
tacts so that both stationary contacts make
with the moving contacts simultaneously
and wipe l/64” to 3/64” when the armature
is aganist the core.
For double trip type units, adjust the third
contact so that it makes with its stationary
contacts at the same time as the two main
contacts or up to 1/64” ahead.
2. Target: Manually raise the moving contacts
and check to see that the target drops at the
same time the contacts make or up to 1 / 16"
ahead. The cover may be removed and the
tab holding the target reformed slightly if
necessary. However, care should be exer-
cised so that the target will not drop due to a
slight jar.
3. Pickup: Unit should pickup at 98% of rating
and not pickup at 85% or rating. If
necessary the cover leaf springs may be ad-
justed. To lower the pickup current, use a
tweezer or similar tool and squeeze each
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