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When was your Rotary Screw Compressor last overhauled?

 Is here to offer you a step-by-step approach when determining if your Rotary Comrpessor is worth overhauling. 

ECA ALWAYS recommends you have a STRICT safety policy.

If you have an efficient, quality compressor that is old or broken down, it is worthwhile to consider rebuilding to save $$$$.

It is always critical when working in or around your rotary compressor that safety is the number 1 thing on your mind. Please make sure to disconnect and lock all electrical supplies before attempting any inspection. Always vent any compressed air remaining.

Get the Service and Parts Manual for the compressor. If you are unable to locate this, contact the team and we will try and track one down. Usually, compressor manufacturers provide the manual for a reasonable fee.

Performing the inspection should be performed by a knowledgeable compressor expert. It may take approximately 4 hours for a V-belt driven compressor. Gear driven or direct coupled compressors may take longer.

How’s your airend?Compressor Airend

The best way to inspect your airend is to run it. Before, make sure running the airend is safe or if it will cause more damage to your machine.

  1. Disconnect the motor from the airend. If the airend is connected to the motor, simply remove the V-belts. If the airend is directly coupled to the motor or is gear-driven, the task is more difficult.

  2. Once you have airend is disconnected, slowly rotate the airend's input shaft by hand.

  3. If the airend rotates, continue rotating it several times. There should be no tight spots when rotating.

  4. Move the airend shaft up and down and from side to side. You should detect only the slightest movement.

  5. If you find any tight spots in the rotation the ECA team can evaluate the airend for possible bearing damage.

If the airend rotates freely and shaft movement is minimal, the airend should be safe to run.

If the airend does not rotate, then we may have to overhaul or even replace the airend itself.

Call our team to discuss airend options


Electric motors

WEG electrid Motor

Disconnect the airend and motor as stated in the previous step, remove any electrical wires and jumpers and turn the motor by hand.

If the motor rotates, continue rotating it several full revolutions. Listen and feel for any cluncking or tight spots that indicate bearing problems. Typically, replacing the motor bearings is a relatively inexpensive repair.

Check the condition of the windings using a Mega-Ohm meter or High Pot Tester.

  • Measure the resistance of each winding. Open windings have more resistance than the others. A short within the winding is identified by a lower reading.

  • Resistance between windings should be extremely high — infinity on some meters — since windings should not be interconnected. A lower resistance in one or two windings may indicate a short between the two windings.

  • Resistance to ground should be extremely high since the windings should not be connected to a ground. A lower resistance in a winding may indicate a short to ground.

If the motor does not rotate, the motor bearings are likely damaged. Check out our new WEG motor Line or Call us for more details.

Control panel

Inspect the control circuits. Be sure to inspect starters, relay timers, terminals, wires and other components for signs of high heat. Look for melted or heated-discolored plastic and burnt contacts. If the components look fine, use a Mega-Ohm meter or High Pot Tester to verify whether the circuit is safe to operate. If you notice damage, replace the components.

Inspect the oil

Much of the wear and dirt collects on the bottom of the separator tank. Drain the tank f\ and analyze the contents. We can subject your oil to a lubrication analysis, call us for details.

 Time to make your Decision!

Contact our Team for Answers!

Phone: 866-650-1937


If your rotary compressor is old and broken down it could be worthwhile to rebuild it into the same efficient machine it was when you first put it into your compressor system. Rotary screw compressors have few major components, the overhaul procedure is fairly straightforward requiring only a reasonable amount of time.

For more information, visit our website or contact our customer service team by calling toll-free: (866) 650-1937 or emailing