
Control scale
Common transformer data settings for all functions in transformer module, protection logic, HMI and
IO.
Settings
Transformer application nominal data
Other features
Status hours counters (normal load, overload, high overload)
Transformer status signals
Transformer data for functions
Outputs
Light /No load
Im < 0.2xIn
Inrush HV side
detected
Im < 0.2xIn
→
Im >1.3 xIn
Inrush LV side
detected
Im < 0.2xIn
→
Im >1.3 xIn
Load normal
Im > 0.2xIn… Im <1.0 xIn
Overloading
Im > 1.0xIn… Im <1.3 xIn
High overload
Im > 1.3xIn
Inaccuracy
Current detection
±3% of set pick-up value > 0.5 x In setting. 5 mA < 0.5 x In setting
Detection time
±0.5 % or ±10 ms
9.2.1.19. Transformer differential (87T,87R) Idb>, Idi>,HV Iod>, LV Iod>
Table. 9.2.1.19. - 280. Transformer differential (87T,87R) technical data
Input signals
Input magnitudes
Phase currents of HV/LV side. Fundamental residual current measurement for HV/LV REF
protection. 2
nd
and 5
th
harmonic measurement.
Characteristic (Differential and REF)
Differential calculation
mode
Bias calculation mode
Add or Subtract (CT direction)
Average or maximum (Sensitivity)
Idb> Pick-up
Turnpoint 1
Slope 1
Turnpoint 2
Slope 2
0.01…100.00% by step of 0.01%, Default 10.00%
0.01…50.00xIn by step of 0.01xIn, Default 1.00xIn
0.01…250.00% by step of 0.01%, Default 10.00%
0.01…50.00xIn by step of 0.01xIn, Default 3.00xIn
0.01…250.00% by step of 0.01%, Default 200.00%
Idi> Pick-up
200.00%...1500.00% by step of 0.01%, Default 600.00%
Internal harmonic
blocking selection
None, 2nd harmonic, 5th harmonic, both.
2
nd
harmonic blocking
Pick-up
0.01…50.00% by step of 0.01%, Default 15.00%
5
th
harmonic blocking
Pick-up
0.01…50.00% by step of 0.01%, Default 35.00%
Inaccuracy
Differential current
2
nd
harmonic
±2.5 %I
SET
or ±50 mA (0.10…4.0 x ISET)
±1.5 %I
SIDE1
Instant operation time
Instant operation time
>1.05xISET
<40 ms (Harmonic blocking active)
AQ-T257
Instruction manual
Version: 2.00
347
© Arcteq Relays Ltd