Compressor Sequencer Control

Compressor Sequencer Control


  • Stages multiple compressors on one or more common suction lines.
  • Use of a common suction pressure sensor or one of the screw compressor sensors.
  • One set of common control parameters on the master sequencer is used for all compressors to eliminate sensor differences and piping loss.
  • Separate control parameters for compressor capacity control and compressor starts/stops
  • Adjustable staging parameters for both staging up and down compressors
  • Starting of next compressor inhibited until trim compressor is fully loaded or limited.
  • Re-configurable lead lists allows easy addition or removal of swing compressors.
  • Multiple lead lists to allow different compressor configurations to be stored and scheduled (Standard is two with more available on request)
  • Ability to select maximum compressors allow to run for each lead list
  • When lead lists are changed, compressors start and stop in a controlled manner to smooth out transitions.
  • Starting of skipped compressors using a standby monitor timer to maintain lead list order, as those compressors become available.
  • Hot standby feature reduces starting and stopping of trim compressor.
  • Support for screw, rotary, and reciprocating compressors.
  • Automatic interlocks between booster and high stage systems
  • Setpoint and lead list scheduling:
    • Four (4) programmable setpoint groups (control setpoint, deadband, low alarm, and low failure).
    • Seven (7) daily schedules each with eight time slots.
    • Each time slot contains a desired lead list and a desired setpoint group
    • Manual override provided for schedule number, setpoint group and lead list.


  • Support for control parameters being changeable by the end user between suction pressure and process temperature.
  • Ability to force a compressor on in anticipation of a load
  • Support for disable ling sequencer based on conditions ( i.e. All zones are satisfied) stopping all compressors

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