22
Thermostat, cooling coil with
changeover function
The chilled-water coil can be set by
the controller to operate as a
cooling coil, or a heating coil, if
warm water is available for this coil.
The controller needs to know if
warm or chilled water is available.
The passive thermostat supplied for
this purpose must be installed on a
supply water pipe after this coil.
Position the thermostat in a place in
the piping system where continuous
flow and a temperature for the
medium can be guaranteed that is
independent of the control damper
position. If the sensor is installed in
the wrong position in the water
piping, the system will not work.
The followings standard settings are reqired.
•
Cooling mode detection: if the measured water
temperature is lower than the value set at the top dial,
set this to 20°C. If the control demands cooling, the
control damper will open, if the water temperature
measured is below 20°C.
•
Heating mode detection: if the measured water
temperature is higher than the sum of the setting
values at the bottom and top dials, set the value at the
bottom dial to 10 K. If the control demands heating,
the control damper will open, if the water temperature
is 20 + 10 = 30°C.
•
If the temperature is between the values above, the
last mode detected applies.
Ensure that the gland is at the bottom.
This sensor (if required) is supplied separately and must be
connected to the control panel after the unit has been
installed. In the control diagram this sensor is shown as
26TA22(TS1)
4.15 - Sensor replacement
• If sensors are replaced, ensure that the new sensor is the
same type as the installed sensor and of a Carrier
authorised replacement type.
• Before connecting the ducts and completing the other
installation procedures ensure that all sensors are still
accessible for maintenance in their final location. This
can be achieved by installing inspection hatches in the
ducts to be connected.
