What are the reasons for the tripping of the screw air compressor?

During the maintenance process of the screw air compressor, overload tripping is something we often encounter, and it can be checked according to the following steps:

1. You should check whether the power supply is in the normal range.

2. Check the contactor and electrical control system.

3. Check whether the bearing of the motor is short of grease.

4. Check whether there is any abnormal sound at the head of the main engine (the bearing feels like it is about to fall off).

5. Check whether the oil separator is blocked. If the pressure difference is too large, it is easy to be overloaded.

According to the above few steps of inquiry, the cause of the overload trip of the air compressor can be basically judged, so how does the motor of the air compressor trip?

Behind the contactor in the electrical control of the screw air compressor, a “thermal relay” is connected. In the thermal relay, the three-phase wires each pass through a bimetallic sheet for conduction. If the motor is overloaded or lacks phase operation, the current increases, and the bimetal sheet of the thermal relay bends gradually. When the bimetal sheet bends enough to push a lever, it can play a protective role. The thermal relay has a reset button, but if the thermal relay operates, find out the reason and don’t rush to reset the operation. The control current of the thermal relay can be adjusted. If it is adjusted properly, it can withstand short-term starting current without action, but it can control excessive operating current. According to the nature of the load, the control current is set within the rated current range of the motor. Once the air compressor exceeds the current value within the set range, the thermal relay will protect and trip the machine directly.

Sollant Group-Professional Compressed Gas Solutions Provider