Viconics T550 User Manual
Cro-st ∆ t, Electronic thermostat, Applications

APPLICATIONS
•
VAV box control
•
Proportional room electric heating control
•
Proportional room hot water heating control
•
Air conditioning control
ADVANCED DESIGN AND PI CONTROL
Advanced microcomputer electronics and PI control algorithms
provides precise temperature control and eliminates wasted
heating energy caused by the typical On-Off cycling in
conventional thermostats. As a result the room occupant is able to
reduce the setpoint or desired temperature to the lowest
comfortable setting. The result is energy savings ranges from 5%
to 10%.
DAY-NIGHT MODE
A night mode, initiated by a remote timer or computer contact,
provides energy savings during unoccupied periods of up to 10 %,
without sacrificing comfort in occupied rooms. A flashing LED
indicator warns an person in an occupied room that the
thermostat is in Night mode. The occupant may override this
condition locally for 4 hours by pressing the switch on the
thermostat.
HIGH COOLING SIGNAL OUTPUT
A optional 0 to 10 Vdc cooling voltage output can be wired to
other thermostats and used as a signal to a voltage relay to
initiate cooling demand.
REPROGRAMMABLE
Each thermostat is computer calibrated and factory programmed
to the ordered specification. However, over 10 control parameters
( such as heating/cooling mode, stage differential, night set-back
etc. ) may be changed in the field with programming tool without
having to remove the thermostat cover. The C263 also doubles as
a diagnostic tool and indicates the status of all the inputs and
outputs to each stat, and will reduce troubleshooting time by
quickly identifying the specific problem.
COVERS
The thermostats are available with 4 covers options in either °C
and °F. Thermostat cover plugs in to base for easy wiring and
service. The base fits onto a standard electrical box. The User
adjustable front models feature internally selectable minimum
and maximum setpoint knob stops.
ELECTRONIC THERMOSTAT:
• TRI-STATE FLOATING
DAMPER MOTOR OUTPUT
• TWO MORE STAGES
• DAMPER CHANGEOVER INPUT
• DAY-NIGHT MODE ( T550 ONLY )
The model T500 and T550 are part of Viconics' Micro-Stat
Series low voltage RHVAC room temperature and
humidity controls line.
DAMPER CHANGEOVER INPUT
When the damper operation is selected for cooling mode, a closed
contact to the changeover input will reverse the operation of the
damper motor to heating mode. In the automatic mode a duct
sensor (S60 or S70) must be installed just before the VAV box.
When duct temperature is higher than room heating set point, the
damper operates in heating mode. When duct temperature is
lower than room cooling set point the damper operate in cooling
mode. With the recirculation mode selected, when the supply
temperature is in the dead zone between the heating and cooling
set point, the damper goes fully open to allow full ventilation.
This feature improves air quality and reduces temperature
variations across the room.
CONTROL OUTPUTS FOR ALL APPLICATIONS
The thermostats are available with various outputs to drive:
•
Relays
•
Motors
•
Contactors
•
SSR's
•
Solenoids
•
SCR Power Controllers
•
Valves
•
Three position motor
SENSORS
Each thermostat can be either room or duct mounted with local or
remote sensors, and can be selected by an internal jumper.
SPECIFICATIONS
Operating Conditions:
0 °C to 50 °C ( 32 °F to 122 °F )
0% to 95% R.H. non-condensing
Sensor:
Local 47 K NTC thermistor
Resolution:
± 0.1 °C ( ± 0.2 °F )
Control accuracy:
( calibrated )
± 0.2 ° C ( ± 0.4 °F ) for low ranges
± 0.9 ° C ( ± 1.8 °F ) for high ranges
Ranges:
10 °C to 32 °C ( 50 °F to 90 °F )
-18 °C to 82 °C ( 0 °F to 180 °F )
Outputs:
Isolated Triac: 30 Vac at ½ A max.
0 to 10 Vdc into 2K
Ω resistance min.
0 / 5 Vdc at 20 mA max. for both outputs.
Power:
24 Vac -15%, +10% 50/60 Hz; 2 VA
DIMENSIONS
Specifications and equipment are subject to change without prior notice.
µ
i
CRO-ST
∆T
T500
T550
0
180
135
90
45
F
VICONICS
5
4
3
2
1
10
9
8
7
6
114 mm
32 mm
( 71 mm )
( 71 mm )
2.8"
2.8"
( 114 mm )
( 83 mm )
4.5"
4.5"
1.275"
3.275"
COVER
SECURITY SCREW
OR FROM BACK
FROM TOP
WIRING
MODEL
VERTICAL
HORIZONTAL MODEL
BASE