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If the unit calibrations are found to be out of limits during installation or
periodic tests, they should be recalibrated as outlined in the following paragraphs.
The calibrations should be made in the laboratory.
below,
normally considered as factory adjustments,
units. The parts may be physically located on Figures 1 and 2.
the relay circuit is shown on the internal connection diagrams, Figures 10, 11 and
12.
P1: Angle of maximum torque adjustment on upper unit
P2: Angle of maximum torque adjustment on lower unit
P3
Ohmic reach of top unit
P4: Ohmic reach of bottom unit
NOTE:
Before making pickup or phase angle adjustments on the units,
be allowed to heat up for approximately 15 minutes, energized with rated
voltage alone,
also important that the relay is mounted in an upright position so that
the units are level.
CONTROL SPRING ADJUSTMENT
Make connections to the relay as shown in Figure 128:
Set voltage to zero ohms
Put basic reach taps in 1. 5 ohm taps
Set current to 1.0 ampere.
Insert the blade of a thin screwdriver into one of the slots in the edge of the
spring adjusting ring (see Figure 2) and turn the ring until the left contact of the
unit just closes.
to close the left contact.
the current to zero, and check that the right contact is closed.
ANGLE OF MAXIMUM TORQUE ADJUSTMENT
The angle of maximum torque is primarily controlled by the adjustment of the
upper rheostat on each unit (P1 for the upper unit, or P2 for the lower unit), .and
by whether a jumper is applied across studs 13-14 and 15-16.
each unit (P3 for the upper unit, or P4 for the lower unit), has a secondary effect
on the angle of maximum torque.
For angle of maximum
connected between studs 13-14, and a second jumper between studs 15-16.
For angle of maximum torque between 30 and 35 degrees, no connections should be
made to studs 13, 14, 15 or 16.
For angle of maximum torque between 25 and 30 degrees,
jumpers between studs 13-14 and studs 15-16 should or should not be used.
vary from unit to unit, depending upon actual value of capacitors C1 and C2.
GEK-49778
and the restraint tap leads set for 100 percent.
Turning the ring to the right will increase the current required
When the left contact just closes at 1. 0 ampere, reduce
torque between 5 and 25 degrees,
SERVICING
The circuit components listed
are used in recalibrating the
16
Their location in
they should
It is
The lower rheostat on
a
jumper
should
determine whether the
This will
be
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