Datasheet

56
Application
The main purpose of motor starters is to start the electrical motor
by switching ON the contactor inside the starter. The relay inside
the starter additionally protects the motor in case of overload and
single phasing condition. The starter is nothing but a pre-wired
assembly of contactor(s), relay and ON-OFF push buttons. Direct
on line and star delta are two methods of starting the electric
motors which is achieved by our DOL and star delta starter
respectively.
Standard
Siemens starters confirms to IS/IEC 60947-4-1
Range
Agricultural starters
3TW42 DOL starters (A1, A2, A3, A4): upto 10Hp
3LW42 Handle operated star delta starters (B1): upto 15Hp
3TS02 Semi-automatic and 3TE02 fully automatic star delta
starters (B2, B3, B4): upto 25Hp
Industrial starters
3TW04 DOL and 3TE04 star delta starters (C1, C2): upto 75Hp
Benefits and features
Flexibility
• Starters with or without enclosure
Pre-wired DOL as well as star delta starters are available either
in open execution or in sheet steel enclosure.
• Industrial starters without relay
Industrial DOL as well as star delta starters have provision for
mounting relay but the relay is not provided in the starter. Thus
offering flexibility of selecting 3UA relay range as per
customers requirement.
Reliability
• Wide band coil voltage
Agricultural DOL starters are having option of 200-400 V and
agricultural star delta starters are having option of 230-400 V
coil voltage which takes care of wide fluctuations in the supply
voltage occurring especially in the remote places.
High performance
• In-built single phasing protection
In case of phase loss the current through the other two
windings increases by 1.732 times the rated current of the
motor. The current now flows only through the 2 bimetallic
strips which should produce the required force on the tripping
mechanism. This needs higher currents for longer time. As
current is not too high so the relay might take higher time to
trip. This can cause damage to the motor. Similar condition
happens in case of phase unbalance. To take care of these
conditions our birelays provided in the starters are constructed
such that they offer a built-in single phasing protection using
differential slider principle.