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Scroll air compressors are positive-displacement type compressors that are commonly used in various applications. Of course, from time to time, something is going to hinder the scroll compressor’s performance. Therefore, it is important to understand the troubleshooting steps you can take when you encounter such issues so that you can find a solution to your problem.
This article will provide examples of troubleshooting tips for a scroll air compressor from a popular manufacturer’s owner’s manual.
Table of Contents
- Scroll Air Compressor Troubleshooting Examples
- FAQs (Frequently Asked Questions)
- Additional Troubleshooting Pages
Scroll Air Compressor Troubleshooting Examples
I have picked out this manual for a Quincy scroll air compressor which provides tips on how to take action on various troubleshooting issues.
Though these troubleshooting tips are specifically provided by Quincy 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 scroll 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 manufacturer directly to obtain it.
It’s very common for scroll compressors to have built-in refrigerated dryers, and so, these troubleshooting tips also include ones for built-in refrigerated dryers. To learn more about them, visit our Refrigerated Air Dryer Guide – Best Refrigerated Air Dryers!
We will take a look at the possible causes, and the correct action to take for the following symptoms:
- The compressor does not start
- The compressor does not stop and/or the safety valve blows
- The pressure difference between stopping and starting cannot be adjusted
- Compressor capacity or pressure below normal
- Compressor overheating and/or shut down by an air temperature switch
- The Dew point is too high
- Condenser pressure too high or too low
- Motor refrigerant compressor stops or does not start
- Evaporator pressure is too high or too low
- Condensate trap continuously discharging air and water
- Electronic condensate drain inoperative
Scroll Compressor Does Not Start
| Possible Causes | Correct Actions |
|---|---|
| Pressure too high | The compressor will start again when the pressure drops to starting pressure. |
| On/off switch malfunctioning or loose connection | Have electrical connections checked? Test switch and replace if necessary. |
| Thermal overload switch | Restart after cooling down. |
| Switch open or motor protection relay tripped | Wait for the switch to cool down. Reset the overload relay and replace the switch if necessary. |
| Air pressure switch out of order | Has the valve been replaced? |
Scroll Compressor Does Not Stop and/or Safety Valve Blows
| Possible Causes | Correct Actions |
|---|---|
| The Air pressure switch opens too late or not at all | Readjust switch and replace if necessary. |
| The safety valve opens too soon | Has the valve been replaced? |
Scroll Compressor Pressure Difference Between Stopping and Starting Cannot Be Adjusted
| Possible Causes | Correct Actions |
|---|---|
| Air pressure switch out of order | Replace if necessary |
Scroll Compressor Capacity or Pressure Below Normal
| Possible Causes | Correct Actions |
|---|---|
| Air consumption exceeds the capacity of the compressor | Check equipment connected. |
| Choked air filter | Remove and check the filter. Replace if necessary. |
| Safety valve leaking | Replace valve. |
| Drive belts slipping | Check the condition of belts and belt tension. correct or replace as required. |
| Compressor element out of order | Consult the manufacturer. |
Scroll Compressor Overheating and/or Shut-down by Air Temperature Switch
| Possible Causes | Correct Actions |
|---|---|
| Insufficient compressor cooling | Clean compressor element fins and fan. Improve ventilation of compressor room. Reset overload relay if necessary. |
| Cooling fans out of order | Check and correct, and reset the overload relay if necessary. |
| Temperature shutdown switch out of order | Replace switch. |
Scroll Compressor Refrigerated Dryer Dew Point Too High
| Possible Causes | Correct Actions |
|---|---|
| Air inlet temperature too high | Check and correct. |
| Fuses blown | Check fuses and remedy the cause. |
| Shortage of refrigerant | Has the circuit been repaired or recharged? |
| The refrigerant compressor does not run | See table below. |
| Evaporator pressure is too high | See table below. |
| Condenser pressure is too high | See table below. |
Scroll Compressor Refrigerated Dryer Condenser Pressure Too High or Too Low
| Possible Causes | Correct Actions |
|---|---|
| Fan control switch out of order | Replace the switch. |
| Condenser fan motor out of order | Have the fan motor inspected. |
| Ambient temperature too high | Improve ventilation of compressor room. |
| Condenser externally clogged | Clean condenser. |
Scroll Compressor Refrigerated Dryer Motor Refrigerant Compressor Stops or Does Not Start
| Possible Causes | Correct Actions |
|---|---|
| The internal thermal protection of the motor has tripped | The compressor will restart when the motor windings have cooled down. |
| Electric power supply to refrigerant compressor interrupted | Check and correct as necessary. |
Scroll Compressor Refrigerated Dryer Evaporator Pressure Is Too High or Too Low
| Possible Causes | Correct Actions |
|---|---|
| Condenser pressure too high or too low | See table below. |
| Shortage of refrigerant | Have the circuit repaired or recharged. |
| Hot gas bypass valve incorrectly set or out of order | Have the valve adjusted or replaced. |
Scroll Compressor Refrigerated Dryer Condensate Trap Continuously Discharging Air and Water
| Possible Causes | Correct Actions |
|---|---|
| Automatic drain out of order | Have the drain checked and replaced as necessary. |
Scroll Compressor Refrigerated Dryer Electronic Condensate Drain Inoperative
| Possible Causes | Correct Actions |
|---|---|
| Drain system clogged | Clean the filter of the automatic drain by opening the manual drain valve. Check the functioning of the drain by pushing the test button. |
FAQs (Frequently Asked Questions)
You will know if your scroll air compressor is bad if it is not working as efficiently as it should. It may be that the scroll compressor does not start, does not stop, and/or the safety valve blows, the pressure difference between stopping and starting cannot be adjusted, the capacity or pressure is below its normal level, or the scroll compressor is overheating and/or shut-down by an air temperature switch.
Some of the most common causes of scroll compressor failure include system leaks, dirty/clogged filters, dirty condensers, rapid loading/unloading, misadjusted controls, and wrong oil for the system’s refrigerant.
Additional Troubleshooting Pages
Air Compressor Types Troubleshooting
- Centrifugal Air Compressor Troubleshooting
- Rotary Vane Air Compressor Troubleshooting
- Rotary Screw Air Compressor Troubleshooting
- Reciprocating 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 scroll air compressor troubleshooting, please leave a comment below, with a photo if applicable, so that someone can help you!
