AC Controls

Manual Starters and Switches




Class MMS and MRS





These motor starting switches provide





manual ON / OFF control of single or





three-phase AC motors, where overload





protection is not required, or is provided










These devices are suitable for use with





AC three-phase motors up to 10 HP.





Compact construction and a 600 volt





rating make these switches suitable for



Type F02

a wide range of industrial and commer-

Type K02

cial uses. Typical applications include





Class SMF

small machine tools, pumps, fans, con-

versions allowing more wiring space. A

Class SMF fractional horsepower

veyors, and many other types of electri-

zinc alloy die casting or non-metallic

starters provide overload protection as

cal machinery. They can also be used

enclosure is used for NEMA Type 4

well as manual ON / OFF control for

on non-motor loads such as resistance

enclosures. NEMA 7 & 9 enclosures are

small motors in a variety of industrial


supplied as standard with provisions for

and commercial installations.

The continuous current rating is 30

locking in the ON or OFF position.

Available in one or two pole versions,

amperes at 250 volts max., 26.4 am-

Standard red or non-standard green

these devices are suitable for use with

peres at 277 volts max., 20 amperes

neon pilot light units are available facto-

AC single phase motors to 1 HP. Two

at 600 volts max, 30 ampere resistive

ry installed in NEMA Type 1 surface and

pole starters can also be used with DC

at 600 volts max.

flush mounting, and NEMA Type 4

motors to 3⁄ HP. Typical applications

Class MMS, two-speed manual switch-

enclosures, or as a field modification kit



for NEMA Type 1 enclosures and gray

include fans, conveyors, pumps, and

es may be used with separate winding,

small machine tools. The continuous

three-phase or single-phase AC motors

flush plates.

current rating is 16 amperes.

where overload protection is not

An “Emergency-OFF” toggle operator

Overload trip assembly motor protection

required, or is provided separately. Two

extender is available for NEMA Type 1

is provided by a Type SMFH thermal

switches are employed to give ON /

surface mounted units. The extender

heater element which must be installed

OFF control in each speed.

has a red vinyl button that provides a

before the starter will operate.

Class MRS, reversing manual switches

fast and easy method for locating and

Two-Speed Class SMF manual starters

provide a compact means of starting,

switching the device’s toggle operator

are designed for control of small single

stopping and reversing AC motors where

into the OFF position. The Emergency

phase AC motors having separate wind-

overload protection is not required, or is

OFF Actuator is available in kit form

ings for high and low speed operation.

provided separately. They are suitable for

only for field installation.

Two toggle operated starters are used,

use with three-phase squirrel cage

An optional Handle Guard / Lock-OFF on

with overload protection included for

motors, and for single-phase motors

NEMA Type 1 enclosed starters pre-

each motor winding. Surface mounting

which can be reversed by reconnecting

vents accidental operation of the toggle

devices, and those with a gray flush

motor leads. Two switches are used, one

and also allows the toggle operator to

plate, utilize a mechanical interlock

to connect the motor for forward rota-

be padlocked in either the ON or the

which allows direct control of the motor

tion, and one for reverse.

OFF position. This handle guard can be

by means of the toggle operators.

Class SMF, MMS and MRS

factory installed on NEMA Type 1



enclosed starters and is also available in



NEMA Type 1 surface mounting enclo-



kit form for field installation on NEMA



sures are sheet steel with a thermoplas-



Type 1 surface and flush mounting



tic wrap-around cover for convenience



enclosures. Standard NEMA Type 4



in wiring. The NEMA Type 1 enclosure



metallic enclosures include provision for



is also available in oversized and jumbo



padlocking in the OFF position.

Typical Wiring Diagrams











Class SMF

Class MMS















1 Pole

2 Pole

2 Pole with

2 Pole –– 1 Phase

3 Pole –– 3 Phase

Selection Switch


Controls AC

CSI Section 16160

Siemens Electrical Products and Systems



Specification Guide