Critical Failure Relay #8 - GE 845 Instruction Manual

CHAPTER 4: SETPOINTS
RESET (Command)
SETPOINT
TYPE
Latched
Self-Reset
Pulsed
SETPOINT
OPERATE
Off = 0
Operation (from Protection,
Control, or Monitoring Elements)
SETTING
Relay ( Ready = 1)
BLOCK
Off = 0
Relay ( Ready = 1)
Critical Failure Relay
#8
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
EVENTS
Range: Disabled, Enabled
Default: Enabled
Figure 4-42: Auxiliary Relays generic logic
The 845 relay is equipped with one output relay (# 8 - "Critical Failure Relay") for failsafe
indication. The Critical Failure Relay is a Form-C contact with one NO and one NC contact
(no control power). There are no user-programmable setpoints associated with this output
relay. The logic for this relay is shown below.
Figure 4-43: Critical Failure Relay 8 Scheme
This setpoint is displayed only
upon "Pulsed" output type selection
SETPOINT
SEAL-IN TIME
t
892828A3.cdr
OUTPUTS
Operate Aux Output Relay
FLEXLOGIC OPERAND
Aux Relay X ON
Relay ( Ready = 1)
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