Shen li machinery....

Screw air compressor high temperature overhaul method

The prerequisite is that the temperature of the screw air compressor machine room is within the permitted range, and the oil level is in the normal state (please refer to the random instruction).

First confirm whether the machine temperature measuring element is faulty, you can use another temperature measuring instrument to calibrate, if you confirm that the temperature measuring element is not a problem, and then check the temperature difference between the inlet and outlet of the oil cooler, which is normally between 5 to 8 degrees.If the temperature is greater than this range, it means that the oil flow is insufficient, there is a blockage in the oil circuit, or the temperature control valve is not fully open, please check the oil filter (with a substitute oil filter to consider whether the flow is insufficient), please check the pre-filter. Some models have oil flow adjustment, please adjust to the maximum, check whether the temperature control valve is normal, you can remove the spool, close the end of the temperature control valve, forcing all the oil through the cooler, if the above ways failed to solve, we must consider whether the oil circuit is blocked by foreign objects.

If the temperature difference is less than the normal range, it proves that the heat dissipation is poor, water cooler, please check whether the water inlet is insufficient, whether the water temperature of the water inlet is too high, whether the cooler scaling (water part), whether there is grease inside the cooler (oil part), air-cooled, please check whether the radiator is too dirty, whether the cooling fan is abnormal, insufficient wind, whether the wind pipe is clogged with air ducts, whether the air ducts are too long, whether the fan is not added to the relay fan, whether the fan is not opened or the fan is not faulty. The relay fan is not turned on or the relay fan is faulty. Whether there is grease inside the radiator.
If the temperature difference is in the normal range and the machine is still high temperature, it means that the heat generation of the head is out of the normal range, so you should check whether it is over-pressure operation, whether the oil is not right, whether the oil is aging, whether the head bearing problem or even end face friction.
In addition, there are oil cut-off valve (also known as oil supply valve, stop valve), to check whether there is a failure, oil cut-off valve failure will generally jump on the boot, the temperature rises linearly.

1 、 Failure phenomenon: high exhaust temperature of the set (more than 100℃)

- The lubricating oil level of the set is too low (it should be visible from the oil speculum, but not more than half).
- The oil cooler is dirty and needs to be de-scaled with special cleaning agent.
- The oil filter core is clogged and needs to be replaced.
- Failure of temperature control valve (bad components), cleaning or replacement.
- Failure of fan motor.
- Failure of fan motor; Damage to cooling fan.
- Exhaust duct is not smooth or exhaust resistance (back pressure) is large.
- Ambient temperature exceeds the specified range (38℃ or 46℃).
- Faulty temperature sensor.
- Pressure gauge failure (relay control unit).

2, fault phenomenon: unit oil consumption or compressed air oil content is large

- Too much lubricating oil, the correct position should be observed when the unit is loaded, the oil level should not be higher than half of this time;
- Oil return pipe blockage.
- The installation of oil return pipe (distance from the bottom of oil separator core) does not meet the requirements.
- Exhaust pressure is too low when the unit is running.
- Rupture of the oil separator core.
- Damage to the internal partition of the separator core.
- There is oil leakage from the unit.
- The lubricating oil is deteriorated or used beyond the expiration date.

3 、Fault phenomenon: low pressure of the unit

- The actual gas consumption is greater than the output of the unit.
- Failure of bleeder valve (cannot be closed when loading).
- Air inlet valve malfunction, can not be fully opened.
- Minimum pressure valve is jammed, need to clean, readjust or replace with new parts.
- Leakage in the customer’s pipe network.
- Pressure switch set too low (relay controlled units).
- Malfunctioning pressure sensor; Malfunctioning pressure gauge (relay controlled units); Malfunctioning pressure sensor.
- Faulty pressure gauge (relay-controlled unit); Faulty pressure switch (relay-controlled unit).
- Faulty pressure switch (relay-controlled unit); Faulty pressure sensor; Faulty pressure gauge (relay-controlled unit); Faulty pressure switch (relay-controlled unit).
- Pressure sensor or pressure gauge input hose leakage.

4, fault phenomenon: unit exhaust pressure is too high

- Failure of intake valve, need to be cleaned or replaced.
- Pressure switch setting is too high (relay control unit).
- Pressure sensor failure
- Pressure gauge failure (relay control unit).
- Pressure switch failure (relay control unit).

5 、Fault phenomenon: unit current is large

- Voltage is too low.
- Loose wiring, check whether there are traces of heating and burning.
- The pressure of the unit exceeds the rated pressure.
- Oil separator core clogged, need to be replaced.
- Contactor failure.
- Fault of main machine (can remove the belt and check it by several revolutions by hand).
- Failure of main motor (can remove the belt and check it by several turns of hand-cranking), and measure the starting current of motor.

6, fault phenomenon: the unit can not start

- Fuse bad; Temperature switch bad; Fuse bad; Temperature switch bad; Temperature switch bad; Temperature switch bad
- Temperature switch is bad.
- Check whether the main motor or the host has the phenomenon of jamming, and whether the motor is reversed.
- Main motor thermal relay action, need to be reset.
- Fan motor thermal relay action, need to be reset.
- Transformer is bad.
- Fault not eliminated (PLC control unit).
- PLC controller failure.

7 、 Fault phenomenon: the unit starts when the current is large or trip

- User air switch problem
- Input voltage is too low.
- Star-delta switching interval time is too short (should be 10-12 seconds).
- Faulty air inlet valve (too big opening degree or stuck).
- Loose wiring, check whether there are traces of heat.
- Failure of the main machine (can remove the belt and check by hand for several revolutions).
- Main motor failure (can be removed from the belt with a few turns by hand disk car to check) and start again to measure the starting current.

8, fault phenomenon: fan motor overload

- Fan deformation
- Fan motor failure.
- Fan motor thermal relay failure (aging), need to re-adjust or replace the new parts.
- Loose wiring
- Cooler clogging.
- Large exhaust resistance.

9 、 Failure phenomenon: host stuck, causing the unit to jump off the machine

- The set adopts poor quality lubricating oil, which increases the friction resistance of the host under high temperature and high pressure, causing the host to bite; the bearing of the host has been used for a long time, which needs to be replaced.
- The bearing of the main unit has been used for a long time and needs to be replaced.
- The installation of belt or pair of wheels is not correct.

Post time: Aug-28-2023