Damper

Actuators

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Topics

Key Selling Features (DDA, DDC, DDB, DDD)

Applications

Questions

DDA

Direct Mounted

17-70 in-lb (2-8Nm)

Actuator Travel

Indicator

Magnetic Clutch

Overload Protection

DDA

Push Button Manual Override

Floating Control signal on the DDA

Life expectancy of 60,000 cycles

Adjustable angle of rotation up to 95 degrees

DDC

Direct Mounted

17-70 in-lb (2-8Nm)

Actuator Travel Indicator

Magnetic Clutch

Overload Protection

Push Button Manual

Override

DDC

Modulating 4-20mA or

0-10 VDC control

Position feedback signal

Life expectancy of

60,000 cycles

Adjustable angle of

rotation up to 95 degrees

DDA and DDC

DDB

Direct Mounted

Thru shaft design

88-265 in-lb (10-

30Nm)

Actuator Travel

Indicator

Magnetic Clutch

Overload Protection

DDB

Push Button Manual Override

Floating Control signal on the DDB

Life expectancy of 60,000 cycles

Adjustable angle of rotation up to 95 degrees

DDD

Direct Mounted

Thru shaft design

88-265 in-lb (10-

30Nm)

Actuator Travel

Indicator

Magnetic Clutch

Overload Protection

DDD

Push Button Manual

Override

Modulating 4-20mA or

0-10 VDC control

Position feedback signal.

Life expectancy of

60,000 cycles

Adjustable angle of

rotation up to 95 degrees

DDB and DDD

Applications

Damper Control in Building Automation

Systems

Air Handlers

VAV Boxes

VAV Boxes

A VAV (variable air volume)

box controls the air addition

to a room or zone depending

on temperature

A damper inside the VAV

box controls the airflow

A damper actuator

modulates the damper

according to temperature

VAV Box with Reheat

Application with an

actuator controlling

the damper and

giving position

feedback

VAV Box In a BAS System

Negative

Pressure Room

Has VAV Box

on air inlet

Bypass Dampers

A Bypass Damper is

a pressure relief valve

placed between the

supply and return

ducts of the forced

air duct work.

Bypass Dampers

As Zone dampers start closing,

the bypass damper will open

and divert some of the supply

air to the return.

This prevents a pressure

buildup in the supply duct

which can cause fan cavitation,

excessive air velocities, and

excessive zone damper blow-

by

Air Handlers

The air handler decides how much air to reuse,

bring in new, and exhaust in a building

Dampers control the airflow through the air

handler

Return Air from the building

Outside Air from outside the building

Exhaust Air from the building and exhausted to

outside

Questions

To order a free catalog or for more information contact;

Dwyer Instruments, Inc., P.O. Box 373,

Michigan City, IN., 46361

Telephone: (800) 872-9141 or (219) 879-8000

Fax: (219) 872-9057

Internet address: www.dwyer-inst.com

E-mail: info@dwyer-inst.com