Carnes DTR User Manual

Imperial [IP] Dimensions

Metric (SI) in Parentheses

SPECIFICATION SHEET

Model DTO/R
(Double Thermostat Override Release)
For Combination Fire/Smoke Dampers

CARNES COMPANY 448 S. Main St., P. O. Box 930040, Verona, WI 53593-0040 Phone: [phone] Fax: [phone] www.carnes.com

COPYRIGHT © 2009 CARNES COMPANY

ALL RIGHTS RESERVED

40023, pg 1

Prior to today’s advancements in smoke control techniques, fan systems were required to shut down during fire
conditions and fire dampers were closed by heat. Air pressures were not utilized for the control and containment
of smoke. In recent years, the requirement that systems completely shut down and fire dampers close and remain
closed during fire conditions, has been questioned. With the current Combination fire/smoke dampers may need
to operate at temperatures above and beyond their initial closure rating. Carnes’ DTO/R option provides the capa­bility to override rated damper closure from a secure remote location (such as a fire fighter’s smoke
control command of a remotely located control to permit utilization of the HVAC/Engineered Smoke Control
System, but only until such time as the fire conditions exceed the maximum design limit. The DTO/R options also
permits a combination fire/smoke damper to be reopened after afire emergency has been controlled providing the
temperatures at the damper have cooled down below the maximum design limit. Please note that the DTO/R
option is recommended only for use in systems utilizing an Engineered Smoke Control design.

The DTO/R option is available on all Carnes Combination Fire/Smoke Dampers.

Manufacturer’s Recommendations

All moving parts of the damper must be inspected and cycled at intervals not greater than every 12 months or in accordance with the latest
edition of NFPA 90A, 92A, local codes and the actuator manufacturer. In addition, fuse links shall be removed and inspected for corrosion. Dry
lubricants are recommended.

Indicator Switch Electrical Limitations

• 10 Amperes, 1/4 HP, 120 or 240 Volts A.C.

• .5 Ampere, 125 Volts D.C.

• .25 Ampere, 250 Volts D.C.

• 5 Amperes, 120 Volts (Lamp Load)

• 15 Amperes, 24 Volts D.C.

F/S DAMPER DTO/R OPERATION

Switch is in Normal (Open) Position damper motor is energized until thermo­stat senses temperature above initial closure rating. Above temperature
closure rating, the damper motor is de-energized and damper closes.

Switch may then be moved to the Override Position and the damper will
reopen and remain open until maximum operating temperature is reached.
Once this temperature has been reached the damper motor is de-energized
and the damper closes.

Switch in Closed Position damper motor is de-energized and damper is closed.
Detailed wiring diagrams including terminal designation and/or wire color

coding furnished with each shipment.

L1

L1

L2

L2

OVERRIDE
CLOSED
NORMAL (OPEN)

120 or 24 volt ac damper actuator power

Devices to left of dashed line are located
remotely from damper - furnished by others.

Devices to right of dashed line are factory
mounted on damper.

Field wiring terminates at splice points
indicated by “ ”.

Electric damper actuator or electric/
pneumatic solenoid valve (power on opens
damper, power off closes damper).

Temperature sensing device
(opens when temperature reaches maximum operating rating).

Temperature sensing device
(opens when temperature exceeds initial closure rating).

Position indicator switch
(closes when damper is open).

Position indicator switch
(closes when damper is closed).

Blue

Yellow
Yellow

Red

Smoke detector may be field or factory supplied.

Black

Orange

Open/closed auto switching

Any supply voltage compatible

with lights & switches.

Damper open indicator light.

Damper closed indicator light.

Red

Smoke
Detector
(if used).

40023, pg 2

L1 L2

Blue

Yellow

Black

Orange

Red

DTO/R Wiring Details

L3, L4 is a Supply Voltage Compatible with Lights and Switches. Standard Voltage is Same as
Actuator Ordered.

L3 L4

S1

S2

Yellow

Red

M1

Blk.

Blk.

Control

Panel

Remote

Command

Station

Switch Package

Wiring

Compartment

Motor

Actuator

Wire Nut

Blue

Org.

TS1

TS2

Smoke Detector

If Used

Blk. Blk.

Red Light

Closed

Blk. Blk.

Green Light

Closed

S1

S2

TS1

TS2

Yellow

Red

Yellow

Red

Blue

Black

Orange

HL High Limit
Temp. Sensor
Manual Reset

FS Primary

Heat Sensor

Manual Reset