Siemens LV 10 · 2004
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Switch Disconnectors and FusesIntroduction
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Overview
Type 3LD20 3LD21 3LD22 3LD25 3LD27 3LD28
SENTRIC LD main control and EMERGENCY-STOP switches from 16 A to 125 A
Rated uninterrupted current
I
U
at 35°C ambient temperature A16 25 32 63 100 125
Rated operating voltage
U
eV 690 690 690 690 690 690
AC-3 motor load switch
operational switching of individual motors
at 220 ... 240 V kW 3.0 4.0 5.5 11.0 18.5 22.0
at 380 ... 440 V kW 5.5 7.5 9.5 18.5 30.0 37.0
at 660/690 V kW 5.5 7.5 9.5 15.0 22.0 30.0
AC-23A main control switch,
maintenance switch
Frequent, but not operational switching of
individual motors
at 220 ... 240 V kW 4.0 5.0 6.0 11.0 18.5 22.0
at 380 ... 440 V kW 7.5 9.5 11.5 22.0 37.0 45.0
at 660/690 V kW 7.5 9.5 11.5 18.5 30.0 37.0
Switch versions
Front mounting
•Central ✓ ✓ ✓ ✓ – –
•Four-hole ✓✓✓✓✓✓
Base mounting
•Central ✓ ✓ ✓ ✓ – –
•Four-hole ✓✓✓✓✓✓
Distribution board mounting ✓✓✓✓✓✓
Molded-plastic enclosure
•Heavy-gauge threaded joints ✓✓✓✓✓✓
•Metric screws ✓ ✓ ✓ ✓ ✓ ✓
Switch accessories
4th pole (N conductor)
(leading switch-on,
delayed switch-off contact)
✓✓✓✓✓✓
N terminal ✓ ✓ ✓ ✓ ✓ ✓
PE/ground terminal ✓✓✓✓✓✓
Auxiliary contacts
1 NO + 1 NC ✓ ✓ ✓ ✓ ✓ ✓
1 NO ✓✓✓✓✓✓
1 NC ✓ ✓ ✓ ✓ ✓ ✓