High temperature is one of the most common issues encountered during the operation of air compressors. Overheating can lead to equipment damage and reduced efficiency. This article outlines the 12 most common causes of high temperatures in air compressors, offering insights and solutions to help you maintain optimal performance.
1. Environmental Temperature and Air Density
A: As temperature increases, air density decreases (similar to how air compressors perform less efficiently at high altitudes). This results in decreased compressor efficiency, leading to longer operational times and more load, causing the compressor to generate more heat and higher temperatures.
| Altitude M | Ambient temperature ℃ | |||||
| <30 | 30-40 | 45 | 50 | 55 | 60 | |
| 1000 | 107 | 100 | 96 | 92 | 87 | 82 |
| 1500 | 104 | 97 | 93 | 89 | 84 | 79 |
| 2000 | 100 | 94 | 90 | 86 | 82 | 77 |
| 2500 | 96 | 90 | 86 | 83 | 78 | 74 |
| 3000 | 92 | 86 | 82 | 79 | 75 | 70 |
| 3500 | 88 | 82 | 79 | 75 | 71 | 67 |
| 4000 | 82 | 77 | 74 | 71 | 67 | 63 |
| This table gives the permissible load percentage value of the motor rated power | ||||||
B: Air compressors are typically designed to operate within an environment temperature range of 30-40°C. If the environment exceeds this temperature range, the compressor’s internal temperature may increase and potentially exceed its protective shutdown temperature, leading to overheating.
2. Oil Shortage in the Compressor System
Check the oil level in the oil-gas separator. After shutting down and depressurizing, the oil should be slightly above the high oil level mark (H or MAX). During operation, the oil level should not drop below the low oil level mark (L or MIN). If the oil level is low or not visible, refuel immediately.
3. Malfunctioning Oil Shutoff Valve
The oil shutoff valve, typically a two-way normally closed solenoid valve, opens when the compressor starts and closes when the compressor shuts down to prevent oil from continuing to enter the compressor head. If the valve fails to open during startup, the compressor will overheat due to insufficient oil, potentially leading to severe damage to the screw assembly.
4. Issues with the Oil Filter
A: A blocked oil filter or a non-operating bypass valve can prevent oil from reaching the compressor head, causing rapid overheating.
B: A partially blocked filter can restrict oil flow, causing the compressor to gradually overheat, especially during unloading. During unloaded operation, the compressor oil pressure drops, and oil struggles to pass through the filter, increasing the temperature.
5. Malfunctioning Thermal Control Valve
The thermal control valve is installed before the oil cooler and helps maintain the discharge temperature above the dew point. If the valve fails, oil may bypass the cooler and go directly into the compressor head, causing high oil temperatures and eventual overheating. Common issues include worn-out springs or valve body damage, which can be repaired or replaced.
6. Improper Oil Adjustment
Ensure that the oil adjustment mechanism is functioning correctly. If necessary, increase the oil flow slightly. However, make adjustments only as per manufacturer guidelines.
7. Worn or Degraded Oil
Over time, oil degrades and loses its ability to lubricate and transfer heat efficiently. This can result in higher temperatures, as the compressor struggles to dissipate the heat
8. Cooling System Malfunctions
For water-cooled units, check the temperature differential between the inlet and outlet water pipes. A difference of 5-8°C is ideal. If it’s lower than 5°C, scale buildup or blockages may be present, impairing the cooling efficiency.
For air-cooled units, check whether the ambient temperature is too high. Ensure that the cooling fans are functioning properly. If any issues are identified, address them promptly to prevent overheating
9. Incorrect or Low-Quality Lubricating Oil
Using improper or low-quality lubricating oil can reduce efficiency and lead to high temperatures. Always follow the manufacturer’s specifications regarding oil type and quality.
10. Blocked Air Filters
A clogged air filter increases the compressor load, keeping it in a continuous loading state. This can lead to overheating. Check the differential pressure switch for warnings or replace the filter if necessary. While reduced air output is the first sign, overheating is the secondary issue.
11. Excessive System Pressure
Pressure is typically set at the factory, but if adjustments are necessary, ensure that they match the compressor’s rated pressure. Excessively high pressure leads to increased load, which can cause overheating. This may also lead to higher motor current, triggering compressor protection shutdowns
12. Blocked Oil-Gas Separator
A blocked oil-gas separator can cause internal pressure to rise, leading to overheating. The main issue here is increased internal pressure, which causes various operational problems, including high temperatures.
Preventive Measures and Regular Maintenance
To ensure smooth operation, especially during the hot summer months, it’s crucial to perform regular maintenance on your air compressor. Keep an eye on oil levels, check the cooling system, and replace filters as needed to prevent overheating and maintain peak performance.
Baldor Air Compressors: Efficient, Reliable, and Trustworthy.
Keywords: Air compressor high temperature, compressor overheating, air compressor maintenance, oil shortage, oil filter issues, thermal control valve, cooling system, compressor pressure issues, Baldor air compressor.
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