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Rotary screw air compressors are very common compressors available in today’s market. They are used for a wide variety of applications across many industries. Like any machine, they are likely to have some troubleshooting issues that will require action.
This article will provide examples of troubleshooting tips for a reciprocating air compressor from a popular manufacturer’s owner’s manual.
Table of Contents
- Rotary Screw Air Compressor Troubleshooting Examples
- FAQs (Frequently Asked Questions)
- Additional Troubleshooting Pages
Rotary Screw Air Compressor Troubleshooting Examples
I have picked out this manual for an Eaton rotary screw air compressor which provides tips on how to take action on various troubleshooting issues.
Though these troubleshooting tips are specifically provided by Eaton for one of their models of rotary screw compressors, it is likely that you will be able to transfer this information and apply it to your rotary screw air compressor.
I will recommend reviewing your reciprocating air compressor’s owner’s manual to find the troubleshooting guidance provided by your manufacturer. If you do not have the manual, then search for it online or contact the manufacture directly.
We will take a look at the possible causes, and the correct action to take for the following symptoms:
- Compressor will not start
- Compressor shuts down under compression
- Air pressure is too low
- Line pressure exceeds upper preset safety limit
- Air exhaust temperature lower than normal
- Excessive air exhaust temperature causing compressor to shutdown
- Excessive oil consumption
- Pressure relief valve opens repeatedly
- Water in air sytem
- Excessive noise level
- Excessive vibration
- Black residue on belt guards
- Shaft seal leak
- Low air pressure in storage tank while compressor maintains programmed air pressure
Rotary Screw Compressor Will Not Start
| Possible Causes | Correct Actions |
|---|---|
| Electrical power supply problem | Check complete circuit for proper voltage, ensure all electrical connections are secure; once electrical power is restored, press Enter button on the controls. |
| Blown circuit fuse and/or internal fuse | Replace fuses as required. |
| Poor contact on start push button | Have an electrician or manufacture of the compressor inspect and replace the push button. |
| Failed electric motor | Have an electrician or manufacturer of the compressor dealer inspect and replace the push button. |
| Failed compressor pump | Attempt to move by hand to check for free movement of pump. If not possible, contact the manufacturer’s customer service. |
Rotary Screw Compressor Shuts Down Under Compression
| Possible Causes | Correct Actions |
|---|---|
| Loss of control voltage | Reset-Press Enter button on controls. If trouble persists, check line pressure does not exceed the maximum operating pressure of the compressor (specified on the nameplate). |
| Low incoming voltage | Wire size for power supply too small. Contact local power company. |
Rotary Screw Compressor Air Pressure is Too Low
| Possible Causes | Correct Actions |
|---|---|
| Air demand too high | Decrease the air consumption or increase the number of compressors in the system. |
| Blocked air filter | Clean or replace the air filter. |
| Inlet valve not opening properly which reduces incoming airflow | Disassemble and clean the inlet valve. Apply lubricating oil to the valve. |
| Improperly adjust pressure regulator | Adjust pressure regulator to proper settings. |
| Load solenoid not operating properly | Disassemble and clean solenoid valve. Replace if needed. Check for proper voltage – 220V required. |
| Low oil level | Top up the oil to the correct level. |
| V-belts slipping | Adjust belt tension |
| Air leak | Check compressor & complete air system for air leaks. |
| Compressor running in unload mode | Check pressure switch settings; make sure unload pressure is set properly. |
Rotary Screw Compressor Line Pressure Exceeds Upper Preset Safety Limit
| Possible Causes | Correct Actions |
|---|---|
| Control system leak causing pressure signals to be lost | Check pressure switch for leaks and/or air restriction. Repair as needed. |
| Defective pressure switch/sensor | Check for damage to diaphragm and contacts. Replace if necessary. |
| Defective solenoid valve | Replace valve. |
| Defective blow-down valve | Check that sump pressure is exhausted in the atmosphere when the machine is unloaded. Repair or replace if necessary. |
| The high-pressure shut-down preset is incorrectly programmed | Reset to the proper setting. |
| Additional compressor piped into the system causing preset to be exceeded | Reset additional compressor pressure settings to 145 psi or lower |
Rotary Screw Compressor Air Exhaust Temperature Lower Than Normal
| Possible Causes | Correct Actions |
|---|---|
| Compressor running under no-load excessively | Reset motor shut-down time |
| Temperature sensor malfunction | Replace temperature sensor |
Rotary Screw Compressor Excessive Air Exhaust Temperature Causing Compressor to Shutdown
| Possible Causes | Correct Actions |
|---|---|
| Low oil level | Add oil to a sufficient level |
| Incorrect oil used | Drain all oil and replace it with oil recommended by the manufacturer |
| Blocked oil filter | Replace oil filter |
| Surrounding temperature too high | Check for air exhaust blockage. Increase air ventilation |
| Blocked cooler | Clean cooler |
| Temperature sensor malfunction | Replace temperature sensor |
| Cooling fan failure | Replace cooling fan |
Rotary Screw Compressor Excessive Oil Consumption
| Possible Causes | Correct Actions |
|---|---|
| Clogged return/scavenge line or orifice | Clear blockage |
| Damaged or improperly functioning air/oil separator filter | Change air/oil filter |
| Excessive foaming | Drain and change the oil |
| Oil level too high | Drain oil then check at sight glass for proper level |
| Lubrication system leak | Check all pipes, connections, and components. Repair if necessary |
| The low minimum pressure in the separator tank | Minimum pressure should be around 65 psi depending on make and model |
Rotary Screw Compressor Pressure Relief Valve Opens Repeatedly
| Possible Causes | Correct Actions |
|---|---|
| Defective pressure relief | Replace valve |
| Clogged air/oil separator | Replace filter |
Rotary Screw Compressor Water in Air System
| Possible Causes | Correct Actions |
|---|---|
| Defective moisture separator/Drain trap | Inspect & clean if required; Replace separator if necessary |
| Trap drain or drain piping blocked | Inspect & clean |
| Aftercooler core dirty | Inspect & clean |
| No aftercooler on unit | Install aftercooler |
| Drain line/drip leg incorrectly installed | Slope drain line away from the trap; Install drip leg |
| No refrigerated or desiccant air dryer in the air system | Contact manufacturer |
Rotary Screw Compressor Excessive Noise Level
| Possible Causes | Correct Actions |
|---|---|
| V-belts slipping | Adjust belt tension or replace belts |
| Compressor defective | Replace bearing; contact manufacturer |
| Enclosure panels not in place | Install enclosure panels |
| Loose component mounting | Inspect & tighten |
| Shipping brackets in place | Remove shipping brackets |
Rotary Screw Compressor Excessive Vibration
| Possible Causes | Correct Actions |
|---|---|
| Loose component mounting | Inspect & tighten |
| Motor or compressor bearing failure | Replace bearing; contact manufacturer |
| External sources | Check for other sources of vibration, other than the compressor |
| V-belts slipping | Adjust belt tension or replace belts |
| Shipping brackets in place | Remove shipping brackets |
Rotary Screw Compressor Black Residue on Belt Guards
| Possible Causes | Correct Actions |
|---|---|
| V-belts loose | Adjusted belt tension |
| Sheave misaligned | Align sheaves |
| Excessive belt wear | Replace belts |
| Using non-OEM belt | Use only OEM parts |
Rotary Screw Compressor Shaft Seal Leak
| Possible Causes | Correct Actions |
|---|---|
| Defective shaft seal | Replace or contact the manufacturer |
Rotary Screw Compressor Low Air Pressure in Storage Tank While Compressor Maintains Programmed Air Pressure
| Possible Causes | Correct Actions |
|---|---|
| Check valve installed between compressor & storage tank | Remove check valve |
| Air dryer frozen-up restricting airflow | Bypass dryer |
| Inline filter between compressor & storage tank is clogged | Replace filter |
FAQs (Frequently Asked Questions)
How do I troubleshoot my air compressor?
To troubleshoot your air compressor, you are best following the guidance in your compressor’s user manual provided by the manufacturer. This will contain all the possible issues you may encounter, why they have been encountered, and steps to take to fix them. If you cannot locate your compressor’s user manual, you should contact the manufacturer directly.
Do rotary screw compressors run constantly?
If the rotary screw has a 100% duty cycle and is rated for continuous use then yes, the compressor can run constantly. They typically have better cooling systems to allow them to run for extended periods of use.
Additional Troubleshooting Pages
Air Compressor Types Troubleshooting
- Centrifugal Air Compressor Troubleshooting
- Rotary Vane Air Compressor Troubleshooting
- Reciprocating Air Compressor Troubleshooting
- Scroll Air Compressor Troubleshooting
Air Compressor Part Specific Troubleshooting
- Air Compressor Troubleshooting, Solutions, Common Problems & Causes
- Air Compressor Check Valve Troubleshooting
- Air Compressor Electrical Troubleshooting
- Air Compressor Pressure Regulator Troubleshooting
- Air Compressor Pressure Switch Troubleshooting
- Air Compressor Reed Valve Troubleshooting
- Air Compressor Smells Like It’s Burning? Troubleshooting Compressor Burning Smell
If you have any questions regarding rotary screw air compressor troubleshooting, please leave a comment below, with a photo if applicable, so that someone can help you!
