In last month’s column [“Automatic Pumpdown Systems,” Nov. 5], we talked in general about the automatic pumpdown cycle and why it is the only sure remedy for refrigerant migration to a compressor ...

The way we control the speed of fan motors or pump motors has tremendously changed in the past two decades with the introduction of variable-frequency drives (VFDs), aka variable-frequency controllers ...

Withclosed loop speed control, the fan controller ensures that the fan isrunning at the desired speed by measuring the actual speed and adjustingthe duty cycle accordingly. Here the host specifies the ...

Fan control is an important aspect of system architecture. Though often left as a secondary activity, its implementation has significant effects. Customer response can be immediate to factors such as ...