LV1_17.book Seite 2 Freitag, 26. Januar 2007 11:33 11
Siemens AG 2007
SENTRON Switching and Protection Devices Switch Disconnectors
Introduction
Overview
Type 3LD20 3LD21 3LD22 3LD25 3LD27 3LD28
3LD main and EMERGENCY-STOP switches from 16 A to 125 A
Rated uninterrupted current I
u
at 35 C ambient temperature A 16 25 32 63 100 125
Rated operational voltage
U V 690 690 690 690 690 690
e
AC-3 motor load switches
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 switches, maintenance switches
Frequent, but not operational switch-
ing of single 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
Floor mounting
Central -- --
Four-hole
Distribution board mounting
Molded-plastic enclosures
Metric screwed glands
Switch accessories
4th pole (neutral conductor)
(leading switch-on,
delayed switch-off)
N terminals
PE-ground terminals
Auxiliary contact elements
1 NO + 1 NC
Available
-- Not available
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17LV1_17.book Seite 14 Freitag, 26. Januar 2007 11:33 11
Siemens AG 2007
3KA, 3KE, 3LD Switch Disconnectors
3LD Main Control and EMERGENCY-STOP Switches up to 125 A
General data
Overview
7
3
8
2
6
3
1
5
4
1 4th contact (N conductor)
2 N or PE/ground terminal, continuous
3 Auxiliary switch 1 NO + 1 NC
4 Rotary operating mechanism, red/yellow
5 Rotary operating mechanism, black
6 Front plate, English/German
7 Terminal cover, three-pole
8 Terminal cover, one-pole
Application
The 3LD switches are used for switching main and auxiliary In EN 60204-1 (VDE 0113 Part 1), main control switches are
circuits, but also for switching induction motors and other loads calledmains isolating device, while EMERGENCY-STOP
during maintenance and repair work. switches are termeddevices for emergency shutdow.
Maintenance personnel can protect themselves against
They are manually operated switch disconnectors according to
unauthorized startup with padlocks (up to three can be fitted).
IEC 60947-3/VDE 0660 Part 107 (EN 60947-3) and comply with
the conditions for switch disconnectors. 3LD main control and EMERGENCY-STOP switches are
approved according to UL 508.
The 3LD can be used as
ON-OFF switch
EMERGENCY-STOP switch
Main control switch according to EN 60204-1
* You can order this quantity or a multiple thereof.
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