ABB RET630 - Underfrequency Protection; Overfrequency Protection; Frequency Gradient Protection Main Settings

Table 58. Frequency gradient protection (DAPFRC) main settings
Parameter Function Value (Range) Step
Start value DAPFRC -10.00...10.00 Hz/s 0.01
Operate delay time DAPFRC 0.120...60.000 s 0.001
Table 59. Overfrequency protection (DAPTOF)
Characteristic Value
Operation accuracy At the frequency f = 35 to 66 Hz
± 0.003 Hz
Start time
1)2)
f
Fault
= 1.01 × set
Start value
Typical < 190 ms
Reset time < 190 ms
Operate time accuracy in definite time mode ±1.0% of the set value or ±30 ms
Suppression of harmonics DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,
…
1) Frequency before fault = 0.99 × f
n
, f
n
= 50 Hz
2) Includes the delay of the signal output contact
Table 60. Overfrequency protection (DAPTOF) main settings
Parameter
Function Value (Range) Step
Start value DAPTOF 35.0...64.0 Hz 0.1
Operate delay time DAPTOF 0.170...60.000 s 0.001
Table 61. Underfrequency protection (DAPTUF)
Characteristic
Value
Operation accuracy At the frequency f = 35 to 66 Hz
± 0.003 Hz
Start time
1)2)
f
Fault
= 0.99 × set
Start value
Typical < 190 ms
Reset time < 190 ms
Operate time accuracy in definite time mode ±1.0% of the set value or ±30 ms
Suppression of harmonics DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,
…
1) Frequency before fault = 1.01 × f
n
, f
n
= 50 Hz
2) Includes the delay of the signal output contact
Transformer Protection and Control 1MRS756788 A
RET630
Product version: 1.0 Issued: 15.09.2009
42 ABB