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GEK-2 64 23
Since all the values of T in the above table are negative, these equations impose no restrictions on
the tap setting for this application.
Thus, the relays may be set in the range of 10 to 61 percent.
Since the 61 percent setting will insure that the relay will reach only to the remote bus, a lower
setting should be used.
It is desirable to set the relay to reach at least 25 to 50 percent beyond the
remote terminal.
Thus, for 50 percent additional reach the restraint tap setting should be:
61
T
=
-
41 percent
Set tap on 40 percent
These same calculations should be repeated for the relays at the remote end of the line at terminal B.
If the application is for directional comparison carrier, it will also be necessary to determine the set
tings of the carrier starting CEYG51A relays at both terminals.
The carrier start relay settings should
be at least 1.25 times the setting of the tripping relay at the remote terminal.
This will insure that
the carrier starting relay at the rear terminal will outreach the carrier tripping relay at the remote
terminal and they will, therefore, coordinate properly.
In any event the carrier starting units should
be set as sensitively as possible.
In any case, ALWAYS set the relays that must coordinate with each other on the same basic minimum tap
setting.
Thus, the carrier start CEYG51A relay at terminal B should be set with the same basic minimum
reach setting as the tripping CEYG51A relay at terminal A.
If zero sequence current compensation is used, equation Ic should be used instead of equation lb.
Thus, we obtain.
6.95
-
2.36
4.59
K
=
=
=
0.65 per unit
3(2.36)
7.08
T
=
0.33K
=
0.33 x 300
=
99 percent
For the ground fault F2 immediately behind the relay, use the equation of Appendix III to calculate
the maximum safe reach setting when using zero sequence current compensation.
CONSTRUCTION
The Type CEYG51A relay consists of three mho—type, 4—pole induction cylinder units.
Each unit has an
associated tapped autotransformer for controlling reach and adjustable resistors in the polarizing and
restraint circuits for adjustment of angle and basic minimum ohmic reach.
Figures 1 and 2 show construc
tion details of the relay.
Internal connections of the relay are shown in Figure 3.
The components are mounted on a cradle assembly which can be easily removed from the relay case.
The
cradle is locked in the case by means of latches at the top and bottom.
The electrical connections between
the case block and cradle block are completed through a removable connection plug.
A separate testing
plug can be inserted in place of the connection plig to permit testing the relay in its case.
The cover
attaches to the case from the front and includes the target reset mechanism and an interlock arm to pre
vent the cover from being replaced until the connection plug has been inserted.
Outline and panel drilling dimensions are shown in Figure 15.
RECEIVING, HANDLING AND STORAGE
These relays, when not included as a part of a control panel, will be shipped in cartons designed to
protect them against damage.
Iriniediately upon receipt of a relay, examine it for any damage sustained in
transit.
If injury or damage resulting from rough handling
is
evident, file a damage claim at once with
the transportation company and promptly notify the nearest General Electric Apparatus Sales Office.
Reasonable care should be exercised in unpacking the relay.
If the relays are not to be installed
immediately, they should be stored in their original cartons in a place that is free from moisture, dust,
and metallic chips.
Foreign matter collected on the outside of the case may find its way inside when the
cover is removed and cause trouble in the operation of the relay.
9
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