Wye-Delta Starters

Wye-Delta motors are similar in construction to standard squirrel cage motors, except both ends of each of the three (3) windings are brought out to terminals. By using starters having the required number of contacts properly wired, the motor starts in Why and runs in Delta. This starter can be built as either an open or closed transition device. The closed transition starter requires an extra contactor and resistor bank and are considerably more expensive. By far, the majority of Wye-Delta starters supplied world wide are OPEN transition type.

By starting with Wye connection, line current is reduced to one-third (1/3) of the current which would be obtained with a Delta connection.

This starter is frequently applied to unload compressors and other loads that require less than 33% of normal starting torque.

 

Full Voltage and Part Winding Starters

Full Voltage Magnetic Starters provide the simplest method of starting and stopping AC squirrel cage motors. a full voltage starter connects the motor windings directly to the power line. It consists of magnetically actuated switch and thermal overload relay.

A typical squirrel cage motor when started across-the-line will result in a line current of approximately 6 times full load current as shown in the diagram.

Part-Winding Reduced voltage Starters are the simplest type reduced voltage starters.

Part-Winding motors have two sets of identical winding which are energized in sequence to reduce the starting inrush current. The two identical windings are operated in parallel. Most (but not all) 230/460 volt motors are suitable for part-winding start is required. During the period when one winding only is energized, a part-winding motor will draw approximately 60-70% inrush current and will develop approximately 40-50% torque.

 

AC	60Hz	50Hz
-G	24	24
-A	120	120
-B	200	200
-C	220	220
-H	277	230
-E	480	380
-F	600	500
DC add $60
-MSW	12VDC
-NSW	24VDC
-OSW	48VDC
-PSW	110VDC
-RSW	220VDC

AC	60Hz	50Hz
-G	24	24
-A	120	120
-B	200	200
-C	220	220
-H	277	230
-E	480	380
-F	600	500
DC add $90
-NSW	24 - 28VDC
--OSW	42 - 48VDC
-PSW	110 - 127VDC
-RSW	220 - 250VDC

AC/DC	50/60Hz +DC
-N	24 - 28v
-AP	110 - 127V
-CR	220 - 250V
-EX	440 - 500V