Rockwell Automation Allen-Bradley SMC-PLUS Bulletin 150, Installation Manual

Page: 13 / 25

3 Chapter Set-up Procedures: SMP PLUS
Controller without Options
During the “Starting” and “Running” modes, the controller’s microcomputer
monitors the following conditions. If any of the conditions exist, the controller
shuts down and lights the FAULT LED and the appropriate LED. The controller
provides the following protection:
•
Start Fault
•
Temperature Fault
•
Stalled Motor
•
Line Fault
Any fault condition will cause the auxiliary contacts to change over and hold in
circuit to release.
NOTE: The Fault LEDs remain ON as long as control power is applied to the
logic. If control power is removed, the controller resets and the LEDs turn
off.
The controller also has advisory LEDs. They indicate:
•
Energy Saver Active
•
Running Mode
•
Stopping Mode
•
Control Voltage Present
•
Starting Mode
The Start Fault indicates an abnormal condition has been sensed. This is any fault
which causes faulty SCR firing (for example, open SCR gate). If the fault occurs in
this category, the controller will attempt to restart three times. After the third
unsuccessful start, the controller will go into a fault condition. The FAULT and
START LEDs light.
The controller is designed to sense motor stall in both the “Starting” and “Running”
modes. If during the “Starting” cycle, the controller senses that the motor is stalled
and the motor remains stalled, the controller shuts down in a predetermined time
based on the selected ramp time. In the “Running” mode, the controller will trip in
5 seconds in the event of a locked rotor condition. The FAULT and STALL LEDs
light. Starting stall trip times are illustrated in the table in Figure 3.1.
The stall option does not replace the need for properly coordinated overload relay
protection.
Figure 3.1 - Starting Stall Trip Characteristics
Soft Start — 2 5 10 20 25 30 — —
Start
Times
Current Limit — — — — — — — 15 30
Times
(sec.)
Full Voltage 1/4 — — — — — — — —
(sec.)
Stall Trip Times (sec.) from Start 5 7 10 10 20 25 30 20 35
The microcomputer monitors the temperature of the SCRs by means of internal
thermistors. When the power poles’ maximum rated temperature is reached, the
microcomputer turns off the SCRs. The controller trips and the FAULT and TEMP
LEDs light.
An overtemperature condition could indicate inadequate ventilation, high ambient
temperature, overloading or excessive cycling.
If an overtemperature condition exists at start-up, the SCR gate signals will be
inhibited to guard against start-up, the controller will trip and the appropriate LEDs
light. After the SCR temperature is reduced to allowable levels, the fault can be
reset by removing and reapplying the control power.
Protective Features
Start Fault
Stalled Motor
Temperature
Fault