Table 46. Negative-sequence overcurrent protection for machines (MNSPTOC)
Characteristic Value
Operation accuracy At the frequency f = f
n
±1.5% of the set value or ±0.002 × I
n
Start time
1)2)
I
Fault
= 5.0 × set
Start value
Typically 43 ms (±15 ms)
Reset time <70 ms
Reset ratio Typically 0.96
Retardation time <35 ms
Operate time accuracy in definite time mode ±1.0% of the set value or ±35 ms
Operate time accuracy in inverse time mode
±5.0% of the theoretical value or ±30 ms
3)
Suppression of harmonics DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,…
1) Negative-sequence current before = 0.0 × I
n
, f
n
= 50 Hz
2) Includes the delay of the signal output contact
3)
Start value
multiples in range of 1.10...5.00
Table 47. Negative-sequence overcurrent protection for machines (MNSPTOC) main settings
Parameter
Function Value (Range) Step
Start value MNSPTOC 0.01...0.50 pu 0.01
Operating curve type MNSPTOC ANSI Def. Time
IEC Def. Time
Inv. Curve A
Inv. Curve B
-
Operate delay time MNSPTOC 0.10...120.00 s 0.01
Cooling time MNSPTOC 5...7200 s 1
Table 48. Three-phase thermal overload protection, two time constants (T2PTTR)
Characteristic
Value
Operation accuracy At the frequency f = f
n
Current measurement: ±1.5% of the set value or ±0.002 × I
n
(at currents
in the range of 0.01...4.00 × I
n
)
Operate time accuracy
1)
±2.0% or ±1000 ms
1) Overload current > 1.2 × Operate level temperature,
Current reference
> 0.50 pu
Table 49. Three-phase thermal overload protection, two time constants (T2PTTR) main settings
Parameter
Function Value (Range) Step
Temperature rise T2PTTR 0.0...200.0° 0.1
Max temperature T2PTTR 0.0...200.0° 0.1
Operate temperature T2PTTR 80.0...120.0% 0.1
Weighting factor p T2PTTR 0.00...1.00 0.01
Short time constant T2PTTR 60...60000 s 1
Current reference T2PTTR 0.05...4.00 pu 0.01
Generator Protection and Control
1MRS757583 C
Product version: 1.3
ABB 33
To Next Page
Loading...
