Emotron EMX-R Series, Instruction Manual, Page: 12 / 169

Emotron AB 01-3333-01r3 Description 7
1.3.2 Rotation monitor (DIP switch 4)
Two different rotation monitors can be selected. The first, RotoSens

, which is
an integrated electronic rotation monitor, and secondly a rotation monitor
using an external rotation sensor.
RotoSens uses the motor as the sensor. By allowing the control unit to measure
the load on the motor, you can determine whether the drive belt has broken.
When the drive belt has broken, the motor load will be low. As the heat
exchanger rotors which rotate very easily also give a low load on the motor, it is
necessary to also measure the load during acceleration - you then get a
measurement of the rotor’s torque of inertia. After 2 minutes of operation at a
low load, a load measurement is made during acceleration. If the drive belt is
broken an alarm is given, if it is undamaged the load measurement during
acceleration is repeated again after 24 hours. In cleaning mode, measurement
during acceleration is made once every 24 hours.
The rotation monitor with external rotation sensor requires a magnet fitted on
the periphery of the rotor. The magnet activates the external rotation sensor
once every revolution. Should, for example, a belt break and the rotor stops, the
pulses cease and an alarm is given. The time until the alarm is given is speed
dependent and is 24 seconds at max. speed, 20 minutes at min. speed and about
8 hours in purge mode.
The rotation monitors give alarms through operating indications (display or
LED) and via the alarm relay (external signal). The motor does not stop with
this alarm.
Following rotation monitor functions are available:
• DIP switch 4( see chapter 2.2.7 page 17)in position “OFF” (downwards),
NOTE: In order to use RotoSens the load on the motor should not be too low.
The minimum diameter for the heat exchanger rotor and belt pulley for each
size of the drive system must be:
EMX-R-15: Belt pulley

63 mm, heat exchanger rotor diameter

630 mm
EMX-R-25: Belt pulley

63 mm, heat exchanger rotor diameter

1200 mm
EMX-R-35: Belt pulley

100 mm, heat exchanger rotor diameter

2000
mm
If the belt pulley or heat exchanger rotor are smaller, RotoSens can not be
used, however, the rotation monitor with sensor can always be used.