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GEK-49848A
PHASE DIRECTIONAL OVERCURRENT RELAYS
TYPES
JBC51M
JBC51M(-)Y1A
JBC51P
JBC52M
JBC52P
JBC53M
JBC53P
JBC54M
JBC77M
JBC77P
JBC78M
DESCRIPTION
The Type JBC relays are phase directional overcurrent relays that are used
primarily for the protection of feeders and transmission lines.
They are available
with inverse, very inverse, or extremely inverse time characteristics.
All the JBC relays contain a time overcurrent unit of the induction disk type,
an instantaneous overcurrent cup type unit, and an instantaneous directional cup
type unit.
The directional unit is quadrature polarized, and it directionally
controls the operation of both the time overcurrent disk unit and the instantaneous
cup unit.
Those relays having the designation Y1A following the model number also contain
a Hi-Seismic instantaneous unit of hinged armature contruction.
This unit is non
directional and has a self-contained hand reset target that will show whenever the
unit has operated.
Two target seal-in units are provided in each of the relays.
The operating
coil of each of these units respectively is connected in series with the contacts of
the time overcurrent unit and the instantaneous overcurrent unit.
The contacts of
each seal-in unit respectively are connected in parallel with the contacts of the
time overcurrent unit and the instantaneous overcurrent unit to provide protection
for them and the associated control spring.
All the JBC relays are mounted in standard L2 size drawout cases, the outline
and panel drilling dimensions for which are shown in Fig. 27. Internal connections
for the relays are shown in Figs. 5 thru
9 .
Typical external connections are shown
by Figs. 10 and 11.
These instructions do not purport to cover all details or variations in equipment nor provide for every
possible contingency to be met in connection with installation, operation or maintenance. Should further
information be desired or should particular problems arise which are not covered sufficiently for the
purchaser's purposes, the matter should be referred to the General Electric Company.
To the extent required the products described herein meet applicable ANSI, IEEE and NEMA
standards; but no such assurance is given with respect to local codes and ordinances because they vary
greatly.
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