5.38
SEL-400 Series Relays Instruction Manual Date Code 20171006
Control
Bay Control Example Application
Disconnect Alarm Pickup Delay
This setting monitors disconnect open/close operations (the undetermined time)
of the disconnect switch. When the disconnect alarm timer expires, an alarm con-
dition exists and the 89AL1 Relay Word bit asserts. Set the 89ALPm timer longer
than the expected operation (undetermined state) time, but less than the 89CSITm
or 89OSITm seal-in timers. The expected disconnect operation time in this exam-
ple is 250 cycles. 89ALPm is entered in cycles and has a range of 1–99999.
89ALP01 := 260
Disconnect Close/Open Control
Program SELOGIC control equations 89CCNn and 89OCNn to close or open dis-
connect switch n, respectively. Great care needs to be used when programming
these equations because there are no breaker jumper supervision or access level
safeguards in place for this disconnect operate method. The settings in this exam-
ple close the disconnect switch when Remote Bit 1 is set and open the disconnect
switch when Remote Bit 1 is cleared. The 89CCN01 SEL
OGIC example below
also includes additional supervision logic where the close operation only operates
if Breaker 1 is open (NOT 52CLS1) and the disconnect switch is in the opposite
state (89OPN1). When these conditions are met, a close disconnect operation will
initiate. Relay Word bit 89CLS1 is the output of the seal-in timer and asserts
when Relay Word bit 89CCN01 asserts. Relay Word bit 89OPN1 deasserts as
soon as the disconnect switch starts to move. The OR combination of Relay Word
bit 89CLS1 and 89OPN1 keeps the close disconnect signal asserted until the dis-
connect operation has completed. The SEL
OGIC control equations below demon-
strate disconnect lockout control in the relay. The 89OCN01 SEL
OGIC control
equation illustrates the same type of supervision for the disconnect switch open
logic.
89CCN01 := RB01 AND (89OPN1 OR 89CLS1) AND NOT 52CLSM1
89OCN01 := NOT RB01 AND (89CL1 OR 89OPEN1) AND NOT 52CLSM1
Disconnect Close/Open Seal-in Timers
The seal-in timers assert the close or open signal long enough to allow the dis-
connect operation to complete. Set the seal-in timer 10 to 15 percent longer than
the expected disconnect operate time to give the disconnect switch time to com-
plete the operation. 89CSTm and 89OSTm are entered in cycles and have a range
of 1–99999. The example shown anticipates a disconnect switch operate time of
approximately 250 cycles.
Cold weather and low battery voltages can impact operation times. Be sure to
consider these conditions when setting the seal-in timers.
The output contacts must not be used to break the motor coil current. An auxil-
iary contact with adequate current interrupting capacity must first interrupt cur-
rent supply to the motor before the relay contact opens. Include the auxiliary
contact clearing time when setting the disconnect seal-in timer.
89CST01 := 280
89OST01 := 280
Disconnect 2–5
Disconnect switch settings 2–5 are similar to the Disconnect Switch 1 examples
above. See Table 5.6 for a complete list of Bay Class settings for this application.
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