Allen Bradley SMC-3 and SMC Flex Smart Motor Controllers
SMC™ Flex Smart Motor Controllers
Bulletin 150 — SMC™ Flex Smart Motor Controller
The SMC Flex controller provides microprocessor controlled starting
for standard 3-phase squirrel-cage induction or Wye-Delta (6-lead)
motors. Seven standard modes of operation are available within a
1…1250 A Range
Seven Standard Start Modes
Options Include Pump Control and Braking Control
Built in SCR Bypass/Run
Built in Electronic Motor Overload
CT on each Phase
Four Programmable Auxiliary
The SMC Flex controller is available for motors rated 1…1250 A;
200…480V AC, 200…600V AC, or 230…690V AC, 50/60 Hz. In
addition to motors, the SMC Flex controller can be used to control
Description of Features
Electronic Motor Overload Protection
The SMC Flex controller incorporates, as standard, electronic motor
overload protection. This overload protection is accomplished
electronically with an I2t algorithm.
When coordinated with the proper short-circuit protection, overload
protection is intended to protect the motor, motor controller, and
power wiring against overheating caused by excessive overcurrent.
The SMC Flex controller meets applicable requirements as a motor
overload protective device.
The controller’s overload protection is programmable, providing the
user with flexibility. The overload trip class consists of either OFF,
10, 15, 20, or 30 protection. The trip current is programmed by
entering the motor full-load current rating, service factor, and
selecting the trip class.
Thermal memory is included to accurately model motor operating
temperature. Ambient temperature insensitivity is inherent in the
electronic design of the overload.
The SMC Flex controller’s undervoltage protection will halt motor
operation if a drop in the incoming line voltage is detected.
The undervoltage trip level is adjustable as a percentage of the
programmed line voltage, from 0…99%. To eliminate nuisance trips,
a programmable undervoltage trip delay time of 0…99 seconds can
also be programmed. The line voltage must remain below the
undervoltage trip level during the programmed delay time.
If a rise in the incoming line voltage is detected, the SMC Flex
controller’s overvoltage protection will halt motor operation.
The overvoltage trip level is adjustable as a percentage of the
programmed line voltage, from 0…199%. To eliminate nuisance
trips, a programmable overvoltage trip delay time of 0…99 seconds
can also be programmed. The line voltage must remain above the
overvoltage trip level during the programmed delay time.
Excessive Starts Per Hour
The SMC Flex controller allows the user to program the allowed
number of starts per hour (up to 99). This helps eliminate motor
stress caused by repeated starting during a short time period.
Power monitoring parameters include:
3-phase current Power Factor
3-phase voltage Motor thermal capacity usage
Power in kW or mW Elapsed time
Power usage in kWH or mWH
Note: The motor thermal capacity usage allows the user to monitor
the amount of overload thermal capacity usage before the
SMC Flex controller’s built-in electronic overload trips.
Built-in DPI Communication Capabilities
A serial interface port is provided as standard, which allows
connection to a Bulletin 20 Human Interface Module and a variety of
Bulletin 20-COMM Communication Modules. This includes Allen-
Bradley Remote I/O, DeviceNet, ControlNet, Ethernet, ProfiBUS,
Interbus, and RS485-DF1.
The SMC Flex controller’s three-line 16-character backlit LCD
display provides parameter identification using clear, informative
text. Controller set up can be performed quickly and easily without
the use of a reference manual. Parameters are arranged in an
organized four-level menu structure for ease of programming and
fast access to parameters.
Programming of parameters is accomplished through a five-button
keypad on the front of the SMC Flex controller. The five buttons
include up and down arrows, an Enter button, a Select button, and
an Escape button. The user needs only to enter the correct
sequence of keystrokes for programming the SMC Flex controller.
Four fully programmable hard contacts are furnished as standard
with the SMC Flex controller:
Aux #1, Aux #2, Aux #3, Aux #4
The SMC Flex can have up to two inputs and four outputs
controlled via a communication network. The output contacts use
the auxiliary contacts.
Ground Fault Input
The SMC Flex can monitor for ground fault conditions. An external
core balance current transformer is required for this function. See
SMC Flex User Manual for additional information.
A motor tachometer is required for the Linear Speed Start mode.
Please see the Specifications section on page 22 for tachometer
A motor PTC input can be monitored by the SMC Flex. In the event
of a fault, the SMC Flex will shut down and indicate a motor PTC