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HHCompact Air Handling Units
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
25QT23 (QT).
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 following 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 18°C. If the control demands
cooling, the control damper will open, if the water
temperature measured is below 18°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 18 + 10 = 28°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
26TA23 (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
Systemair B.V. 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.
