Characteristics of Induction Motors
TORQUE
FULL LOAD
SPEED
PERMANENT CAPACITOR MOTORS
Shown is a typical "torque/speed" characteristic for this type of motor, these units are only suitable for
operating from a single phase AC supply and incorporate a permanently connected capacitor.
The speed is fairly constant but it should be borne in mind that the starting torque is lower than the full load
output usually in the order of 85% of full load.
The motor however has the advantage of low starting current and is particularly suited for frequent reversing.
Capacitor motors cause no radio or T.V. interference.
(See below for capacitor details).
SHADED POLE MOTORS
Shown is a typical "torque/speed" characteristic for this motor. The speed is reasonably constant but between
no load and full load the speed variation is greater than the permanent capacitor type.
Starting torque is between 50%-80% full load torque with the advantage of low starting current.
It is important to note rotation is set and cannot be electrically reversed.
This type of motor does not cause radio or T.V. interference.
TORQUE
FULL LOAD
SPEED
CAPACITOR START INDUCTION RUN (CENTRIFUGAL SWITCH)
Shown is a typical "torque/speed" characteristic for this type of motor, the speed is fairly constant over the no
load to full load range. This unit incorporates an internal centrifugal switch which connects the starting winding,
together with an electrolytic type capacitor, in the circuit for a few seconds. This winding and capacitor is only
short time rated, the unit is not suitable for driving high inertia loads or frequent start/stops maximum
recommended 20 per hour.
The starting current is in the order of 3 x full load current. This type of motor can be electrically reversed, but
must not be reversed whilst running, the motor must be allowed to come to rest.
TORQUE
FULL LOAD
SPEED
THREE PHASE MOTORS
Shown is a typical "torque/speed" characteristic for this type of motor and where a 3 phase supply is available
this motor should be the logical choice.
The speed is constant and starting torque is good, in some cases up to 200% full load.
It is possible to instantaneously reverse this type of motor whilst running.
This type of motor does not cause radio or T.V. interference.
The photograph shows the type of capacitor we are
currently stocking.
But other types may be supplied depending upon
availability.
Plastic case with part number, capacity, working voltage
and connection diagram printed thereon.
When two or more capacitors are necessary for operation
then connect the capacitors in parallel.
Capacitors
DATA
Fixing M8 x 13mm long plastic stud and nut, lead length 30cm
MFD
Max Dimension
00
Working Voltage
Part Number
+10%
A Diameter
B Length
440
50150
1.5
30
56
440
50200
2
30
56
440
50250
2.5
30
56
440
50300
3
30
56
440
50400
4
30
56
440
50500
5
30
75
440
50600
6
30
75
440
50840
8.4
35
75
440
50942
42
63.5
98
440
50970
70
76
123
250
51000
10
30
75
250
51050
14
35
75
TORQUE
FULL LOAD
SPEED
7
Induction 1 & 3 Ph