Allen-Bradley SMC-50 Quick Start

Rockwell Automation Publication 150-QS003E-EN-P - April 2017 19
Installation Chapter 1
Bypass Operation and
Diagrams
Bypass operation varies between the SMC-50 controller with internal bypass
and the solid-state controller.
SMC-50 Controllers with Internal Bypass
SMC-50 controllers with internal bypass have one or more built-in contactors
that close when the motor is up to speed. This reduces heat because the motor
current is now flowing though the internal bypass contactor(s) and not
through the SCRs.
SMC-50 Controllers with External Bypass
For external bypass operation, you must supply a bypass contactor. An auxiliary
relay contact that is programmed for external bypass is used to control a
properly sized external contactor once the motor is at full speed.
You can accomplish overload protection in several ways. Table 9
provides a
summary of motor overload protection options.
Table 9 - Motor Overload Protection Options
Power
Structure Type
Catalog
Number
Overload Protection Option
150-SM2 and
825-MCM180
150-SM2,
825-MCM20, and
External CTs
Bypass Kit
External
Overload
Internal Bypass
150-S108…
X
(1)
(1) Not available for inside-the-delta applications.
——X
150-S135…
150-S201…
—X
(1)
—X
150-S251…
150-S317…
—X
(1)
—X150-S361…
150-S480…
Solid-State
150-SB… X — — X
150-SC… — X X X
150-SD… — X X X

Allen-Bradley SMC-50 Specifications

General

Brand	Allen-Bradley
Model	SMC-50
Category	Controller
Language	English