Drawout Relays, General; Power Requirements, General - GE IJC51E Instructions Manual

GEK-65583
or from other sources.
Or if desired, the relay can be drawn out and replaced by
another which has been tested in the laborato ry.
Figures 1 and 2 show the relay removed
from its drawout case with all
major
components identifie d.
Symbols used to identify circuit components are the same as
those which appear on the internal connection diagram in Figure 14.
The relay includes three similar subassembly elements called induction units,
mounted on the front of the cradle.
The induction unit is the basic unit in all IJC relays.
These units are of the
inductio n-disk
construc tion. The disk
is
actuated
by a current operatin g coil
assembled on a laminated U-magnet.
The disk shaft carries the moving contact, which
completes the alarm or trip circuit when it touches the stationar y contact.
The
disk
shaft is restraine d
by a spiral spring
to give the proper contact-c losing
current, and its motion is retarded by a permanent magnet acting on the disk to give
the correct time delay.
There is a seal—in unit mounted on the front, to the left of the shaft.
This
unit has its coil
in series and its contacts
in parallel with the main contacts ,
such that when the main contacts close, the seal-in unit picks up and seals in.
When the seal-in unit picks up, it raises a target into view, which latches up and
remains exposed until released by pressing a button beneath the lower left corner of
the cover.
NOTE: All tests must be performed with the relay in its case or in an equivale nt
case.
TESTS
DRAWOUT RELAYS, GENERAL
Since all drawout relays in service operate in their cases, it is recommended
that they be tested in their cases or an equivale nt steel case.
In this manner, any
magnetic effects of the enclosur e will be accurate ly duplicat ed during testing.
A
relay may be tested without removing it from the panel
by using a 12XLA13A test
plug.
This plug makes connections only with the relay and does not disturb any
shorting bars in the case.
The 12XLA12A test plug may also be used.
Although this
test plug allows greater testing flexibilit y,
it also 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 alternati ng—cur rent-ope rated devices are affected by frequency.
Since non
sinusoid al waveforms can be analyzed as a
fundamental frequency plus harmonics of
the fundamental frequency,
it follows that alternati ng-curre nt devices (relays) will
be affected by the applied waveform.
Therefor e, in order
to test alternati ng-curre nt
relays properly ,
it is
essential to use a sine wave 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
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