Operating range monitoring
Multiple fans driven by multiple motors are connected to a frequency converter. The internal monitoring systems in the frequency converter cannot recognise the failure of an individual fan.
The permissible operating range of the electric motor for each fan is monitored with a cos phi monitoring unit using the “under” function. As soon as the cos phi leaves the acceptable range, for example because of a load reduction due to a defective V-belt or a dirty filter, the relay output is tripped, and the higher-level control system can recognise the fault.
– Fast and low-cost monitoring, simple retrofit
– No sensor needed in the air channel – relevant for dust, heat and aggressive exhaust gases
– Lower maintenance requirements than for direct measurement in the air channel
– Measuring relay suitable for use with frequency converters