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How to avoid issues when restarting machines- contact Compressed Air Controls


If your air compressors or pneumatic equipment ever have a break- say over Christmas- you may come across issues with this equipment on startup. 

Here's how to avoid them when you are leaving the site:

  • Disconnected the compressors main power line to avoid short circuitíng
  • Kept the compressor doors closed to avoid dust entry
  • Closed the cable entry points to avoid rats getting in
  • Avoided moisture and dust entering the system by closing the air outlet valve (after de-pressurizing the system and line) and closing the dryer and downstream filters in and out valves.

Here is a list of issues your pneumatic machinery/air compressors/dryers may have:

  • Weakened circuit breakers or fuse links could finally trip causing loss of power to the machine.

  • Sticky valves will cause machines to malfunction-  MAC Valves don’t stick so we can replace any problematic valves with MAC Valves.

  • Jammed/sticky condensate drains may stay open rather than automatically closing when air pressure builds up

  • A compressor may not “load up” running but not producing air for the factory.

  • Air dryers will take an hour plus to reduce air temperature and remove water.

  • System does not build pressure as drain valves are open in the factory

How to prevent issues:

  • Start machines up one at a time to prevent overloading the power supply causing fluctuation/surges that may cause circuit breakers/overloads to trip.

  • Take caution when starting up compressors as pneumatic machinery that operates on compressed air could have gone into a “relaxed” state due to the compressed air being off. Isolate machines prior to starting the compressor as air pressure is regained then components may start moving.

  • Make sure your staff are not in ‘holiday mode’, encourage them to take extra care, check the air is isolated, check electrically that nothing is going to be compromised.

  • Ensure air intakes and ducting are clear of debris.

Things to check before starting up a compressor:

  • Clean the cooler, pre-filter, air filter and complete machine. (Use dry air with pressure below 2.5 bar). Ensure cleanliness of control panel.
  • Ensure tightness of power cable, control wiring, connectors, transmitters, motor terminal connections and VFD cables – check for damages
  • Check for free rotation of airend and motor
  • Ensure oil levels are as recommended in the manual
  • Ensure oil condition is good and there is no de-colourisation, emulsification, solidification or dust contamination
  • Drain moisture from separator tank and air receiver
  • Clean moisture separator ADV and air receiver ADV
  • Ensure that it is not overdue for a service (i.e. Oil and consumables change, Motor greasing must have not crossed beyond recommended hours/months whichever earlier, as given in manual)
  • Disconnect the air outlet pipe and ensure there are no rust particles

Things to check once it is powered up:

  • Check incoming voltage as per specification and change the transformer tapping accordingly
  • Ensure there are no alarm and trip messages in the PLC
  • Ensure earth voltage is less than 3 volts
  • Check the direction of motor rotation (as per the sticker on motor)

Things to check once you have started the compressor:

  • Check for smooth running without abnormal sound
  • Ensure there are no air and oil leakages in the compressor
  • Ensure there is no water leakage (applicable for water-cooled compressors)

Things fo check for compressors with a VFD:

  • Check for foreign particles, condensation, insects inside panel and VFD. Clean the drive with dry air (air pressure less than 3 bar)
  • Tightness check of all wirings (L1, L2, L3, U, V, W)
  • Check for corrosion on bus bars and earthing (Applicable for standalone VFD)
  • Check the insulation of motor and cables
  • Clean the heat sink, cooling fan and duct channels
  • Check for alarm and warning during power-up
  • Check cooling fan operations
  • Check the healthiness of monitoring parameters on display
  • Start VFD and run in manual unload mode
  • Run system with load