- Phase-Sequence-Change Relays DRR20 measure the sequence of the phases and switch – if necessary the rotation of the field. At the output (connect relays K1 and K2 in series in this application) two contactors are connected. The contactor at the normally-open contact of K2 switches the phases 1:1without changing them, the second (atnormally-closed contact) changes 2 phases.
- automatic change of wrong phase-sequence when connected falsely (2 contactors afforded)
- running backward of motors is avoided
- no switching on at asymmetry or undervoltage
- relay K2 picks up when phase-sequence is correct
- relay K1 picks up (after K2) when symmetry and voltage is correct
- 3 LEDs for state of relays and errors
- measuring-voltage 3 AC 400 V
- limit asymmetry adjustable 5…25 %
- limit undervoltage adjustable 70…95 %
- alarm-delay adjustable 0,1…10 s (undervoltage and asymmetry)
- no supply-voltage required
Thông số kỹ thuật
- Rated supply voltage Us : 3-phase, 400 V without N
- Admissible tolerance Us : +20%...-30%
- Output relay : ca. 3 VA
- Type of contact : 50/60 Hz
- Output relay : 2 change-over contacts (co)
- Type of contact : type 2 see general technical informations
- Test conditions : see general technical informations
- Rated ambient temperature range : -20°C...+55°C
- Limit asymmetry : adjustable 5...25 %
- Limit undervoltage : adjustable 70...95 %
- Hysteresis : app. 2%
- Delay undervoltage/asymmetry : adjustable 0,1...10 s
- Delay phase-loss (<60% Us) : < 0,2 s
- Pick-up delay after recovery of Us : < 0,5 s
- Delay K2 - K1 : app. 100 ms