Air Compressor Protection and Filter Maintenance Reminder

Abstract: Air compressors, like the human body, have self-protection systems. The self-protection of air compressors originates from their warning systems, which include pressure systems, temperature control systems, power systems, three-filter systems, and other warning protections. As long as they malfunction, air compressors

Air compressors, like the human body, have self-protection systems. The self-protection of air compressors originates from their warning systems, which include pressure systems, temperature control systems, electrical systems, and three-filter systems, among others. Whenever these systems malfunction, the air compressor will trigger an alarm to notify the operator of the issue.

(1) Pressure Protection System: Air compressors are equipped with a minimum pressure valve, capacity control (not available on the MLGF-3.6/7G-22 model), pressure control valve, and safety valve control, ensuring the air compressor operates within a specified pressure range.

(2) Temperature Protection System: All models are fitted with temperature switches, with the action temperature typically set at 110°C. Under normal conditions, the cooling system ensures the air compressor operates within the optimal temperature range of 75–95°C. However, insufficient oil injection, cooler blockage, or high ambient temperatures may cause the exhaust temperature to rise. The air compressor can still operate normally as long as the exhaust temperature does not exceed 110°C. Therefore, the pressure-type temperature switch for the WTYK-11B model is set to 110°C. When the exhaust temperature rises to the set value of 110°C due to any reason, the normally open contacts close, causing the air compressor to stop running and the high-temperature exhaust alarm light to illuminate.

(3) Electrical Protection System

(4) Air Compressor Three-Filter Maintenance Reminder System: The MLGF-3.6/7G-22 model is equipped with an air filter maintenance indicator on the air filter, which can be used to replace the air filter element based on its indication. Other models are equipped with air filter, oil filter, and oil separator core differential pressure switches (normally open type), which can be replaced based on the indicator lights on the control panel. All models have an operating timer installed in the electrical control box. For the MLGF-3.6/7G-22 model, the oil filter and oil separator can be replaced according to the maintenance replacement cycle described below. For other models, the three filters can be replaced based on the maintenance replacement indicator and maintenance replacement cycle, whichever comes first.

(5) Principle of air filter, oil filter, and oil separator core differential pressure switch blockage alarm

When the oil filter becomes blocked, the pressure difference between its inlet and outlet increases. When it reaches the set value of the oil filter differential pressure switch (approximately 0.15–0.18 MPa), the normally open contact closes, and the oil filter blockage alarm light illuminates.

When the oil-air separator filter becomes clogged, the pressure difference between its inlet and outlet increases. When it reaches the set value of the oil separator differential pressure switch (approximately 0.12 MPa), the normally open contact closes, and the oil-air separator clogging alarm light illuminates.

When the air filter becomes clogged, the pressure difference between its inlet and outlet increases. When it reaches the set value of the air filter differential pressure switch (approximately 0.008 MPa), the normally open contact closes, and the air filter clogging alarm light illuminates.