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GEK- 264 23
R
2 2
—
M2
unit angle of niaximulTi torque adjustment
R
1 3
-
M3
unit restraint angle adjustment
R
2 3
-
M3 unit angle of maximum torque adjustment
NOTE:
Before making pickup or phase angle adjustments on the mho units, the unit should be allowed to heat
up for approximately 15 minutes energized with rated voltage.
Also it is important that the relay be
mounted in upright position so that the units are level.
RESTRAiNT CIRCUIT ANGLE ADJUSTMENT
The resistors R
1 1
-R
1
- R
13 are used to make the phase angle of the restraint circuit the same as the
phase angle of the polarizing circuit.
This is done to improve the transient performance of the unit.
To
properly adjust R
1 1
-R
12
-R
13 the following is required.
1.
Remove lower connection plug.
2.
Adjust control spring so that the contacts float between the two stationary contacts, when the
relay is de—energized.
3.
Connect studs 15 and 16 to one side of a 70 volt test source.
Connect studs 17 and 18 to the other
side of the 70 volt test source.
Adjust R
1 1 until the moving contact on the top unit floats be
tween the two stationary contacts.
4.
Connect studs 16 and 17 to one side of the 70 volt test source and studs 15 and 18 to the other
side.
Adjust R
1 2 until the moving contact of the middle unit floats between the two stationary
contacts.
5.
Connect stud 15 and 17 to one side of the 70 volt test source and studs 16 and 18 to the other
side.
Adjust R
1 3 until the moving contact of the bottom unit floats between the two stationary
contacts.
DIRECTIONAL CHARACTERISTIC
If the mho unit fails to perform properly at high current levels as outline under ACCEPTANCE TESTS
the inner stator or core must be readjusted.
This can be accomplished by means of rotating the core
(slightly clockwise or counterclockwise as required to make sure that the contacts close and remain
closed within specified currents), with the special core adjusting wrench.
(Cat. No. 0178A9455 Pt. 1)
(See Fig. 12).
MAXIMUM TORQUE ANGLE
The maximum torque angle of the mho—type units can be checked using connections shown in Fig. 10, but
with the E 2 taps disconnected, as outlined in ACCEPTANCE TESTS.
If it is found that the angle of maximum
torque is outside of limits it can be restored by means of the adjustable resistors, R
2 1
, R
2 2
. and R
2 3
for mho units Ml, M2 and M3 respectively.
PICKUP
The pickup or ohmic reach of each unit should be within +14 percent of the published minimum reach
at the angle of maximum torque as checked, in ACCEPTANCE TESTS.
On the CEYG5IA the adjustable resistors
in the restraint circuits (Ril, R12, and Rl3) are used to adjust the angle of the restraint circuit to
equal the angle of the polarizing circuit. This is done so that the restraint torque will be proportional
to the area of the voltage triangle.
Therefore, since
the
resistors R
1 1
, R
1 2 and R
1 3 are used to set the
angle of the restraint circuit, they must not be used to adjust reach.
CLUTCH ADJUSTMENI
The clutch of each unit should slip when a force of 45-65 grams is applied to the moving contact.
The
cup assembly must be held securely with a special wrench 0246A7916 (1/2 inch wrench, 1/32 inch thick)
placed between the front coils and the contact head.
The clutch pressure is varied by loosening or
tightening the self locking nut (3/8 inch) at the top of the cup shaft.
15
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