Viconics T021-M018 - Manual (Page 2)

SEQUENCE OF OPERATION
When 24 Vac is applied to the thermostat, the minimum voltage output going to the actuator is 0 Vdc, or the value adjusted on
the minimal position potentiometer.
When the dry contact closes on the supply sensor wire, the free cooling mode is activated.
The setpoint is adjusted on the thermostat, the range of the setpoint is: 5 °C to 27 °C ( 40 °F to 80 °F ). The voltage output going
to the actuator when the free cooling is activated is the highest value between the PI supply loop or the minimum position
adjustment.
To close the damper two choices are available. Remove power to the thermostat and the control signal will drop to 0 Vdc, this
will close the actuator electrically. Or remove the power to the thermostat and the actuator, this will close the actuator on its
spring mechanism if it is equipped with one.
Sensor and thermostat are made to be operated at temperature as low as -40 °C ( -40 °F ).
WIRING
24 V.a.c.
M18
2 to 10 Vdc
actuator
Ex.: NF24-SR
22-003
Supply
N.O.
N.C.
Mix air setpoint
Fresh air damper
minimum
position
Contact from a relay
authorizing free cooling
Air
Return
Fan
7
6
5
4
1 2 3
24 V.a.c.
Common
Remote
sensor
Output
0 - 10 Vdc
Order
sensor
separately
Air
Fresh
Optionnal contact from a
relay overrides the fresh air
damper to 100%
www.viconics.com Viconics Electronics Inc. 9245, Langelier Blvd, St-Leonard, Quebec, Canada H1P 3K9
[email protected]
LIT-T2118-E01
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