GE Multilin T60 Transformer Protection System 2-23
2 PRODUCT DESCRIPTION 2.3 SPECIFICATIONS
2
UNDERFREQUENCY
Minimum signal: 0.10 to 1.25 pu in steps of 0.01
Pickup level: 20.00 to 65.00 Hz in steps of 0.01
Dropout level: pickup + 0.03 Hz
Level accuracy: ±0.001 Hz
Time delay: 0 to 65.535 s in steps of 0.001
Timer accuracy: ±3% of operate time or ±1/4 cycle
(whichever is greater)
Operate time: typically 4 cycles at 0.1 Hz/s change
typically 3.5 cycles at 0.3 Hz/s change
typically 3 cycles at 0.5 Hz/s change
Typical times are average operate times including variables such
as frequency change instance, test method, etc., and may vary by
±0.5 cycles.
OVERFREQUENCY
Pickup level: 20.00 to 65.00 Hz in steps of 0.01
Dropout level: pickup – 0.03 Hz
Level accuracy: ±0.001 Hz
Time delay: 0 to 65.535 s in steps of 0.001
Timer accuracy: ±3% of operate time or ±1/4 cycle
(whichever is greater)
Operate time: typically 4 cycles at 0.1 Hz/s change
typically 3.5 cycles at 0.3 Hz/s change
typically 3 cycles at 0.5 Hz/s change
Typical times are average operate times including variables such
as frequency change instance, test method, etc., and may vary by
±0.5 cycles.
RATE OF CHANGE OF FREQUENCY
df/dt trend: increasing, decreasing, bi-directional
df/dt pickup level: 0.10 to 15.00 Hz/s in steps of 0.01
df/dt dropout level: 96% of pickup
df/dt level accuracy: 80 mHz/s or 3.5%, whichever is greater
Overvoltage supv.: 0.100 to 3.000 pu in steps of 0.001
Overcurrent supv.: 0.000 to 30.000 pu in steps of 0.001
Pickup delay: 0 to 65.535 s in steps of 0.001
Reset delay: 0 to 65.535 s in steps of 0.001
Timer accuracy: ±3% of operate time or ±1/4 cycle
(whichever is greater)
95% settling time for df/dt: <24 cycles
Operate time: typically 6.5 cycles at 2 pickup
typically 5.5 cycles at 3 pickup
typically 4.5 cycles at 5 pickup
Typical times are average operate times including variables such
as frequency change instance, test method, etc., and may vary by
±0.5 cycles.
BREAKER FAILURE
Mode: 1-pole, 3-pole
Current supervision: phase, neutral current
Current supv. pickup: 0.001 to 30.000 pu in steps of 0.001
Current supv. dropout: 97 to 98% of pickup
Current supv. accuracy:
0.1 to 2.0 CT rating: ±0.75% of reading or ±2% of rated
(whichever is greater)
above 2 CT rating: ±2.5% of reading
BREAKER ARCING CURRENT
Principle: accumulates breaker duty (I
2
t) and mea-
sures fault duration
Initiation: programmable per phase from any Flex-
Logic operand
Compensation for auxiliary relays: 0 to 65.535 s in steps of 0.001
Alarm threshold: 0 to 50000 kA2-cycle in steps of 1
Fault duration accuracy: 0.25 of a power cycle
Availability: 1 per CT bank with a minimum of 2
BREAKER FLASHOVER
Operating quantity: phase current, voltage and voltage differ-
ence
Pickup level voltage: 0 to 1.500 pu in steps of 0.001
Dropout level voltage: 97 to 98% of pickup
Pickup level current: 0 to 1.500 pu in steps of 0.001
Dropout level current: 97 to 98% of pickup
Level accuracy: ±0.5% or ±0.1% of rated, whichever is
greater
Pickup delay: 0 to 65.535 s in steps of 0.001
Timer accuracy: ±3% of operate time or ±42 ms, which-
ever is greater
Operate time: <42 ms at 1.10 pickup at 60 Hz
BREAKER RESTRIKE
Principle: detection of high-frequency overcurrent
condition ¼ cycle after breaker opens
Availability: one per CT/VT module (not including 8Z
modules)
Pickup level: 0.1 to 2.00 pu in steps of 0.01
Reset delay: 0.000 to 65.535 s in steps of 0.001
SYNCHROCHECK
Max voltage difference: 0 to 400000 V in steps of 1
Max angle difference: 0 to 100
° in steps of 1
Max freq. difference: 0.00 to 2.00 Hz in steps of 0.01
Hysteresis for max. freq. diff.: 0.00 to 0.10 Hz in steps of 0.01
Dead source function: None, LV1 & DV2, DV1 & LV2, DV1 or
DV2, DV1 xor DV2, DV1 & DV2
(L = Live, D = Dead)