Table 42. Three-phase thermal overload protection, two time constants (T2PTTR) main settings
Parameter Function Value (Range) Step
Temperature rise T2PTTR 0.0...200.0°C 0.1
Max temperature T2PTTR 0.0...200.0°C 0.1
Operate temperature T2PTTR 80.0...120.0% 0.1
Short time constant T2PTTR 6...60000 s 1
Weighting factor p T2PTTR 0.00...1.00 0.01
Current reference T2PTTR 0.05...4.00 × I
n
0.01
Operation T2PTTR 1 = on
5 = off
-
Table 43. Stabilized and instantaneous differential protection for two-winding transformers (TR2PTDF)
Characteristic
Value
Operation accuracy Depending on the frequency of the measured current: f
n
±2 Hz
±3.0% of the set value or ±0.002 × I
n
Start time
1)2)
Minimum Typical Maximum
Low stage
High stage
36 ms
21 ms
41 ms
22 ms
46 ms
24 ms
Reset time Typically 40 ms
Reset ratio Typically 0.96
Suppression of harmonics DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5, …
1) Current before fault = 0.0, f
n
= 50 Hz, results based on statistical distribution of 1000 measurements
2) Includes the delay of the output contact. When differential current = 2 × set operate value and f
n
= 50 Hz.
Transformer Protection and Control
1MRS756891 M
Product version: 5.0 FP1
ABB 41
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