Thermolec AcuSteam - Manual (Page 3)

Installing and Connecting the ACU-STEAM Humidistat and the Outdoor Sensor
1.1 The humidity sensor is not located at the same place in a wall mount or in a duct mount humidistat and
therefore the two models of humidistats are not interchangeable. Please see Fig.1a and Fig.1b.
1.2 A three wire control cable (not supplied) has to be connected between the wall (or duct) electronic
humidistat and the humidifi er electronic board at the three terminals marked “H-STAT”.
Please respect the sequence and connect
GND to GND 24V to 24V ST1 to IN
1.3 The outdoor sensor S-15 (please see Fig.1c) is supplied with the humidistat (wall or duct mount). It
ideally should be installed on an outside wall facing North. This outdoor sensor automatically reduces the
setting of the humidistat according to the outdoor temperature in order to avoid condensation on windows
during extremely cold days. It does the opposite during the mild days without your having to manually adjust
the humidistat. The outdoor sensor is a 10 kilo-ohms NTC thermistor (negative temperature coeffi cient).
GND 24VST1 COM ODR
Terminal
Block
Jumper
Red LED
Green LED
Humidity
sensor
Fig. 1a Wall Mount Humidistat
Humidity
sensor
Fig. 1b Back View of a Duct Mount Humidistat
Jumper - MUST be removed when outdoor sensor is connected
- remains in place if the outdoor sensor is not used
S-15
Fig. 1c