Please Note: Prices subject to change without notice

Price: $459 + freight & handling + GST

This is a ‘multi-functional’ 3 Phase Squirrel-Cage-Induction-Motor(SCIM) manual starter switch

It can be used to simultaneously demonstrate 3 methods of starting a 3 Phase SCIM motor, i.e.
1. Direct-on-Line(DOL), or Full Voltage starter,
2. Star/Delta, ‘Open circuit transition’ starter,
3. Star/Delta, ‘Closed circuit transition (‘Wauchope) starter.

SET-UP

Connect the six SCIM terminals to the six motor terminals on the starter switch (Note, in the correct sequence i.e. U1 to U1, V1 to V1 etc.)
Connect the external 3 phase 41.5V supply the the Input supply terminals on the starter

To best observe the operation of each starting method, connect a 5A Ammeter in series with Line 1(A1),  and a second 5A ammeter in series with motor lead U1 (A2).
And replace the standard metal coupling (090206-614) with the Inertia Wheel (130712-614)
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Description of Starting Methods
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1. D.O.L operation:
a. Rotate switch from ‘OFF’ in a clockwise(CW) direction one step to Δ (delta).
b. Note the currents and time (in seconds) for the Inertia Wheel to accelerate to full speed.
c, To switch off rotate switch Anti-clockwise(ACW) one step to ‘OFF’
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2. Star/Delta – OPEN Circuit Transition operation:
a. Rotate ACW one step to ‘Y’ (Star).
b. Note the start Star connection currents (i.e. 1/3 the DOL value).
c. By observation of both the Inertia Wheel & Ammeters,
d. note the time (in seconds) for the Inertia wheel to accelerate to full speed.
e. When the current has been observed to fall to the minimum value, rotate the switch quickly CW two(2) steps to Δ (delta).
In this process it will be observed that the motor is disconnected from the line (as it passes through the ‘OFF‘ position) in order for the motors connections to be changed from Star to Delta.
i.e. ‘Open’ circuit transition’.
f. To switch off, rotate switch ACW one step to ‘OFF’
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3. Star/Delta – Closed Circuit Transition (Wauchope) operation: a. Rotate the switch ACW one step to ‘Y'(star).
b. By observation of both the Inertia Wheel & Ammeters note the time (in seconds) for the Inertia Wheel to accelerate to full speed.
c. When the current has been observed to fall to the minimum value, relatively quickly rotate the switch ACW two steps through T1 to T2.         IMPORTANT, PLEASE NOTE:
Step T1 is the first stage of the transition from Star to Delta. It is here a set of 3 relatively low resistance resistors are connected both in Star and in parallel  with the motor,
Note, the resistors are connected across the full voltage and thus will be required to dissipate a large amount of heat.
In practice this is a momentary  transition step and the heat loss is negligible.
Thus the student must be instructed to only dwell at step T1 long enough to observe Ammeter readings.
A Prolonged stay at switch position T1 may cause the resistors to overheat and burn-out.
d. When the switch is at position T2 the star point is opened, Thus without disconnecting the motor from the line the motor winding and resistors are connected in Series and in Delta (i.e.a Delta connected primary resistance starter connection).
e. Rotating the switch ACW one more step to Δ (delta) short circuits the series resistors, thus connecting the motor in Delta across the full voltage with out disconnecting the motor from the supply.
i.e. ‘Closed Circuit Transition.
f. To switch the motor off rotate the switch ACW two steps to ‘OFF’.