Construction - GE CEY51A Instructions Manual

GEK-1275
CONSTRUCTION
The type CEY51A relays are assembled in a deep, large-size, double-end (LZD)
drawout case having studs at both ends in the rear for external connections. The
electrical connections between the relay units and the case studs are made through
stationary molded inner and outer blocks, between which nests a removable connecting
pl ug tha t compl etes the ci rcui ts. The outer blocks attached to the case have the
studs for the external connections, and the inner blocks have the terminals for the
internal connections.
Every circuit in the drawout case has an auxiliary brush, as shown in Figure 8,
to provide adequate overlap when the connecting plug is withdrawn or inserted. Some
circuits are equipped with shorting bars (see internal connections in Figure 9), and
on those circuits it is especially important that the auxiliary brushes make
contact, as indicated in Figure 8, with adequate pressure to prevent the opening of
important interlocking circuits.
The relay mechanism is mounted in a steel framework called the cradle, and is a
complete unit with all leads terminated at the inner blocks. This cradle is held
firmly in the case with a latch at both top and bottom and by a guide pin at the
back of the case. The connecti ng pl ug, bes ides ma ki ng the el ectri cal connecti ons
between the respective blocks of the cradle and case, also locks the latch in place.
The cover, which is drawn to the case by thumbscrews, holds the connecting plugs in
place. The target-reset mechanism is part of the cover assembly.
The relay case is suitable for either semi-flush or surface mounting on all
panels up to two inches thick and appropriate hardware is available. However, panel
thickness must be indicated on the relay requisition in order to make sure that
proper hardware will be included.
A separate testing plug can be inserted in place of the connecting plug to test
the rel ay in pl ace on the panel, ei ther from its own source of current and vol tage,
or from other sources. Or the relay can be drawn out and re pl aced by another that
has been tested in the laboratory.
Figure lA and IB show the relay removed from its drawout case, with all major
components identifi ed. Symbol s used to identify ci rcuit components are the same as
those that appear on the internal connection diagram in Figure
9.
The relay includes three similar mho subassembly elements mounted on the front
of the cradl e and a pl ate wi th transformers and transactors mounted on the back of
the c radl e.
The mho subassembly includes the four-pole unit and associated circuit
components. Adjustable reactors XII, XIZ, X13, used in setting the angle of maximum
torque, and rheostats RII, RIZ, R13, used in setting the basic minimum reach, can be
adjusted from the front of the relay.
The transactors (TR-01-Z, TR-0z-3, TR-03-1) with their tap blocks are mounted
on the back. The relay must be removed from its case to make the transactor (or
minimum ohm) settings.
See Figure 8, Cross Section of Case and Cradle Block Showing Auxiliary Brush
and Shorting Bar.
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