About Motion Control
KVAL 990-F4 Service Manual
4-4
Typical Positioning Systems
Typical Contactor Control
Unlike general-purpose relays, contactors are designed to be directly connected to
high-current load devices. Contactors are designed to control and suppress the arc pro
-
duced when interrupting heavy motor currents.The figure below shows a block dia
-
gram of a typical contactor circuit with typical voltages.
FIGURE 11.
Typical Contactor Control
PLC
Output
Fuse(s)
Line
Voltage
(Power)
Motor
Contactor
Control
(Coil)
Input
Power
Input
Power
Output
Control Circuit
Common
ON
Should measure
Control Voltage
120 VAC here
Should measure
Line Voltage here
Should measure
Line Voltage here
Should measure
Line Voltage here
ON
Relay
120 VAC
DC -
Should measure
24 VDC here
Control Voltage