GE t60 Instruction Manual page 215

5 SETTINGS
Figure 5–78: SAMPLE INTERLOCKING BUSBAR PROTECTION SCHEME
Assume that Phase IOC1 is used by Devices 2, 3, and 4 to block Device 1. If not blocked, Device 1 would trip the bus upon
detecting a fault and applying a short coordination time delay.
The following settings should be applied (assume Bit 3 is used by all 3 devices to sent the blocking signal and Direct Inputs
7, 8, and 9 are used by the receiving device to monitor the three blocking signals):
UR IED 2:
DIRECT OUT 3 OPERAND
UR IED 3:
DIRECT OUT 3 OPERAND
UR IED 4:
DIRECT OUT 3 OPERAND
UR IED 1:
DIRECT INPUT 7 DEVICE ID
DIRECT INPUT 7 BIT NUMBER
DIRECT INPUT 7 DEFAULT STATE
DIRECT INPUT 8 DEVICE ID
DIRECT INPUT 8 BIT NUMBER
DIRECT INPUT 8 DEFAULT STATE
DIRECT INPUT 9 DEVICE ID
DIRECT INPUT 9 BIT NUMBER
DIRECT INPUT 9 DEFAULT STATE
Now the three blocking signals are available in UR IED 1 as
. Upon losing communications or a device, the scheme is inclined to block (if any default state is set to "On"), or to trip
ON
the bus on any overcurrent condition (all default states set to "Off").
EXAMPLE 2: PILOT-AIDED SCHEMES
Consider a three-terminal line protection application shown in the figure below.
Assume the Hybrid Permissive Overreaching Transfer Trip (Hybrid POTT) scheme is applied using the architecture shown
below. The scheme output operand
GE Multilin
UR IED 2 UR IED 3
: " "
PHASE IOC1 OP
: " "
PHASE IOC1 OP
: " "
PHASE IOC1 OP
: "2"
: "3"
: select "On" for security, select "Off" for dependability
: "3"
: "3"
: select "On" for security, select "Off" for dependability
: "4"
: "3"
: select "On" for security, select "Off" for dependability
UR IED 1
Figure 5–79: THREE-TERMINAL LINE APPLICATION
is used to key the permission.
HYB POTT TX1
T60 Transformer Management Relay
UR IED 1
BLOCK
UR IED 4
842712A1.CDR
,
DIRECT INPUT 7 ON DIRECT INPUT 8 ON
UR IED 2
UR IED 3
842713A1.CDR
5.7 INPUTS / OUTPUTS
, and
DIRECT INPUT 9
5-137
5