Schneider Electric MK-4461 Catalog Page

GENERAL INFORMATION

Proportiona l pneumatic actuator with 11 sq. in. (71 cm2) effectiv e area used to control damper and air valves in heating, vent il ating and air conditioning systems.

OPERATION

The type of positioning, proportional or two-position, is determined by the controller, such as a thermostat or relay. Actuators are posit ioned by air pressure acting upon a diaphragm and piston. Opposing the force on the top of the piston is a spring. The piston force overcomes the spring force, as the air pre ssure increases, extending the actuator shaft if the pressure lessens, the spr ing force retracts the shaft.

MK-44X1

Pneumatic Damp er Actu ato r

General Instructions

CONSTRUCTION

Units are constructed of a sturdy die cast alumin um housing enclosing an easily replaceable beaded molded neoprene diaphragm, steel piston, piston shaft, sintered bronze shaft-gui de bushing and steel spring .

The molded neoprene diaphragm has a circular bead which mates with a gr oove in the pr essure housi ng insuri ng positive locating and sea li ng of the diaphragm with the housing.

Stroke Length: Adjustable 1/2 to 3" (13 t o 76 mm). Factor y set at 2" (51 mm).

Maximum Safe Air Pressure:

30 psig (207 kPa).

Ambient Temperature Limi ts: -20 to 160°F (-29 to

°C).

Mounting: In any position. Mounting bracket, linkage and connector for 5/16" (8 mm ) di am eter push rod included.

Air Connections: 1/8" FNPT. Dimensions: 7-7/16" (189 mm) high x 5-3/4" (146 m m) wide

x 4-7/8" (124 mm) deep.

OPTIONS

None.

ACCESSORIES

AM-111 Crank arm for 5/1 6" di am eter damp er sh aft. AM-112 Crank a rm for 3/8" diameter damper shaft AM-113 Crank a rm for 1/2" diameter damper shaft AM-115 Crank arm for 7/1 6" di am eter damp er sh aft AM-122 Linkage connector straight type AM-123 Damper clip AM-125 5/16" x 20 " da m pe r ro d AM-125- 0 4 8 5/16" x 48 " da m pe r ro d AM-132 Ball joint connector AM-161-3 Damper linkage kit Tool-95 Pneumatic calibration tool kit

Table-1

Nominal Damper

Damper Type

Parallel

Blade

Opposed

Blade

MK-4421 requires 15 psi be available to actuator, MK-4461 requires 20 psi be available to actuator.

Damper ratings are nominal and based on standard (not low leakage) damper at 1" W.C. static pressure and 2000 fpm (10 m/s) velocity.

Area for

Proportional

Control

4.4 sq. ft. 13.2 sq. ft.

5.6 sq. ft. 16.8 sq. ft.

Nominal Damper Area for

Two-Position Control

MK-4421 (8-13 Spring, 20

psi Supply)

Table-2

15 psi

Supply

Single Press.

System

20 psi

Supply

Single or

Dual Pres s.

System

Nominal Torque

Proportional Control

15 psi

Supply

Dual

Press.

System

15 psi

Supply

Single Press.

System

20 psi Supply

Sing le or Dual

Maximum Force

Power Stroke

Dual

Part

Number

Nominal

Operating

Range

Starting

Pressure

Adjustable

Stroke

Based on

1.5 psi

Pressure

to Actuator

15 psi

Supply

Press.

System

psi psi lb. lb. lb. lb. lb-in. lb-in. lb-in.

MK-4401 3-8 3 ± 1 8.25 30.25 38.5 66 7.9 7.9 7.9 MK-4411 5-10 5 ± 1 19.25 19.25 27.5 55 7.9 7.9 7.9 MK-4421 8-13 8 ± 1 35.75 2.75 11 38.5 2.6 7.9 7.9 MK-4451 3-6, 9-12 3 to 6 8.25 8.25 16.5 44 7.9 7.9 7.9 MK-4461 3-6, 11-17 3 to 6 8.25 0 0 16.5 0 0 7.9

Force and torques based on factory set stroke and starting pressure.

Nominal torque for actuators is based on 1.5 psi pressure change at the actuator..

Adjust pressure reducing valve so that listed pressures are available at the actuator.

aReturn

Press.

System

Figure-1 Relationship between Strok e and Control Air

Pressure for MK-4451 Two-Stage Actuators.

Figure-2 Relationship between Strok e and Control Air

Pressure for MK-4461 Two-Stage Actuators.

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