To Next Page

To Previous Page

22 Rockwell Automation Publication 150-QS003E-EN-P - April 2017

Chapter 1 Installation

Bypass Contactor with SMC-50 Bypass Kit (Solid-state Controllers ONLY)

C- and D-Frame SMC-50 controllers with solid-state power structure (cat.

nos. 150-SC… and 150-SD…) can use an optional bypass kit. This bypass kit

allows the SMC-50 controller to perform the overload function and eliminates

the need for the Bulletin 825 converter module and 150-SM2 option module.

Figure 12 - Wiring Diagram for Frame C (Cat. No. 150-SC…) or Frame D (Cat. No. 150-SD…)

Devices with Bypass Contactor and Bypass Bus Kit

(1) Customer supplied.

(2)

SMC-50 controller Bypass bus kit Cat. No. 150-SCBK (Frame C; Cat. No. 150-SC…) or 150-SDBK (Frame D; Cat. No. 150-SD…).

NOTE: Controller FRN 3.001 or higher is required.

(3) Due to current leakage through an SCR in the OFF state (controller stopped), some form of upstream line power isolation is recommended if maintenance is required on the motor.

See the Isolation Contactor Applications for details.

(4) Bypass must be controlled by an auxiliary contact of the SMC-50 controller that is configured for external bypass.

(5) In North America, size the bypass contactor per the motor Hp and FLA. In IEC applications, size the bypass contactor per the motor AC-1 rating. The short-circuit rating of the

bypass contactor must be similar to that of the SMC-50 controller.

NOTE: In addition to a small amount of leakage current flowing through an SCR in the off-state, failure of one or more solid-state power switching components allows uncontrolled

current to flow to the winding(s) of the motor. This could potentially result in overheating or damage to the motor. To prevent potential personal injury or equipment damage,

the installation of an isolation contactor or shunt trip-type circuit breaker capable of interrupting the motor’s locked rotor current on the line side of the SMC-50 controller is

recommended. Operation of the isolation device should be coordinated using one of the SMC-50 controller auxiliary contacts configured to NORMAL.

T1/2

T2/4

T3/6

L1/1

L2/3

L3/5

Motor (1) (3)

Circuit

Protective

Device

3-phase AC line power