Datasheet

25
Contactors for Hoisting Duty
AC slipring motors are most commonly used for the hoisting applications. AC2 duty pertains to starting
and switching off the slipring motors. In case of hoisting duty breaking current is the starting current
and frequency of switching is high.
The table shows the making and breaking capacity at normal and
at hoisting application where Ie indicates the rated full load
current.
Making Breaking
During Normal operation at full load 2.5 * Ie Ie
Hoisting application at full load 2.5 * Ie 2.5 * Ie
During Normal operation at less than 2.5 * Ie Less than Ie
partial load
Application
AC-2 operation is the typical duty for starting and switching off
fully-loaded slipring motors in the starting phase. The rating of
the contactor, to switch the motors, is selected primarily on the
basis of rated make & break capacity and desired electrical
endurance.
Standard
The contactors comply with the “Regulations to low voltage
switchgear” of DIN VDE 0660 and IS/IEC 60947-4-1.
Range
Hoisting duty contactors are available from 110A to 400A
(AC2/AC3 rating).
Benefits and features
Long life
• “Hoisting Duty “Contactors are provided with new design of
contacts (AgSnO
2
instead of AgCdO) resulting in high
electrical and mechanical life.
• They are electrically superior in taking care of excessive stresses
coming on contactors during their operations in crane
applications.
Reliability
• The “Hoisting Duty” Contactors have vacuum impregnated coils
which are suitable for high frequency switching and high
vibrations. This helps in reducing coil failures.
• Side mounted auxiliary contact blocks are screw mounted and
not snap fitted to withstand vibrations and high frequency
operation.
Operator safety
• Arc Chamber Interlock
It prevents the contactor from switching ON, if the arc chamber
is not fitted properly. Thus avoids accidents to plant and
personnel.
• Finger touch proof terminals
It protects against accidental contact with live parts which
ensures operator safety.
High performance
• No duration upto 55°C
Contactors are suitable for operation in service temperature
upto 55°C without derating. This avoids selection of higher
rated contactor, thereby reducing cost.
Selection and ordering data
Hoisting duty contactors –
For high switching frequency / inching applications with AC
coils, 2NO+2NC aux. contacts
Contactor Rated current Ie (A)
Type
Std. pkg.
size AC2/AC3 at 415V (nos.)
6 110 3TF50 00-0A..
8 170 3TF52 00-0A..
1
10 250 3TF54 00-0A..
12 400 3TF56 00-0A..
Coil voltages:
Coil voltage - 50Hz 110V 230V 415V
Code F0 P0 R0
(Other coil voltages are also available)