GEK-65525
A cutaway view of the case, cradle blocks, and connection plug is shown in Figure 4.
DRAWOUT RELAYS, GENERAL
Since all drawout relays in service operate in their cases, it is recof!lmended that
they be tested in their cases or an equivalent steel �ase.
In. th1s w�y, any
magnetic effects of the enclosure will be accurately dupl1cated dunng test1ng.
A
relay may be tested without removing it from the panel, by using a 12X�A13A test
plug.
This plug makes connections only with the relay and does not d1sturb a�y
shorting bars in the case.
The 12XLA12A test plug may also be used; although th1s
test plug allows -greater testing flexibility, it requires CT shorting jumpers and
the exercise of greater care, since connections are made to both the relay and the
external circuitry.
POWER REQUIREMENTS, GENERAL
All alternating-current (AC)-operated devices are affected by frequency. Since
non-sinusoidal waveforms can be analyzed as a fundamental frequency plus harmonics
of the fundamental frequency, it follows that alternating-current devices (relays)
will be affected by the applied waveform.
Therefore, in order to test alternating-current relays properly it is essential
to use a sine wave of current and/or voltage.
The purity of the sine wave (i.e.,
its freedom from harmonics) cannot be expressed as a finite number for any
particular relay; however, any relay using tuned circuits, RL or RC networks, or
saturating electromagnets (such as time-overcurrent relays), would be essentially
affected by non-sinusoidal waveforms.
DIRECTIONAL UNITS
Polarity
Complete polarity tests are made at the factory, but these may be checked by using
the connections shown in Figure 10. Each unt should be checked separately.
The cup
should rotate in the direction to close the left-hand contact (front view).
Pickup
The pickup of the CCP13E relay may be checked by applying rated voltage and
frequency to the relay as in Figure 11. The relay should close its left contact at
the current specified on the nameplate (relays are shipped with current pickup set
to the minimum setting) multiplied by 1.15.
The 1.15 multiplier is used to
compensate for the test being made 300 off the angle of maximum torque (1/cos 300
=
1/0.866
=
1.15). A phase shifter and phase angle meter could be used to give a test
circuit that would test the units at the angle of maximum torque.
However, most
phase-angle meters will not operate correctly with only 0.004 amperes in their
current coils. For this reason, the three-phase test circuit with phase shifter and
phase-angle meter is
not
recommended.
9
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