Despite the market tendencies which go in the direction of continuous control of air flows (VFD/inverter, brushless), in low-cost applications and in plant revamping one can find motors with 3 speed operation.


For this purpose, CRIOTHERM ZETA PLUS proposes a conversion module 0..10 V with 3 relays, having the following characteristics:

  • 4 DIN format with optional integrated display
  • 230 Vac electrical supply
  • Integrated RS485 serial port
  • MODBUS RTU communication protocol
  • 0..10 V analogue piloting signal
  • Up to 3 relay outputs (speeds)
  • Activation steps of the various speeds as a function of the piloting signal, freely settable from the parameter