How to maintain an automatic mixing submersible pump

The maintenance of automatic mixing submersible pumps should be carried out systematically from multiple aspects such as installation and operation, seal inspection, lubrication replacement, rust prevention treatment, electrical safety, abnormal handling, storage and maintenance. The specific maintenance points are as follows:

I. Installation and Operation Specifications

Vertical hoisting: The pump body should be placed upright in water, with a water depth of no less than 0.5 meters. Avoid placing it horizontally or getting stuck in mud and sand to prevent the impeller from getting stuck or the motor from overheating.

Lifting method: When lowering or lifting the earring from the water surface, a dedicated rope must be used to secure it. It is strictly forbidden to pull the cable or the outlet pipe to prevent cable damage or loose joints.

Trial operation: Before starting, power on the ground and let it idle for 3 to 5 minutes to confirm that the rotation direction is correct (without abnormal noise or vibration), and then put it into water.

Water level monitoring: During operation, it is necessary to ensure that the distance from the center of the impeller to the water surface is within the range of 0.5 to 3 meters to prevent the pump body from being exposed above the water surface, which may cause the motor to run dry and burn out.

Ii. Inspection and Replacement of Seals

Daily inspection: Before each use, check the sealing ring, oiling screw, sealing box and other components. Tighten them immediately if any are found loose. Replace them in time if the seal is not tight or ages.

Leakage detection

After a new pump or the replacement of the grinding block: Check the oil (water) leakage after running for 50 hours. If it exceeds 5 milliliters, the sealing box needs to be replaced.

Regular use: Check once a month. The leakage should be less than 25 milliliters; otherwise, the seal needs to be replaced.

Sealing box replacement: Disassemble in sequence, keep clean during assembly, ensure the integrity of the "O" -shaped rubber sealing ring, and prevent water from seeping into the motor interior.

Iii. Lubrication and Oil Change

Oil-immersed submersible pump

Seal chamber oil: Replace it once after 500 hours of operation, using No. 5 or No. 10 cleaning oil.

Motor cavity oil: Change it once a year. It is strictly forbidden to mix different grades of oil.

Wet submersible pump: Replace lithium-based grease after continuous operation for 2000 hours. Calcium-based grease is strictly prohibited.

Bearing lubrication: Regularly check the oil shortage of the bearings. It is recommended to replace the bearings of water-filled electric pumps once a year.

Iv. Rust Prevention and Painting Treatment

Surface rust prevention: After one year of use, inspect the rust condition of the pump body, remove the rust and apply anti-rust paint to protect the metal parts.

Internal rust prevention: If the motor is filled with oil inside, it usually does not require painting. If it is not to be used for a long time, the moisture should be wiped dry and grease applied to prevent rust.

V. Electrical System Maintenance

Insulation resistance detection

Hot-state detection: After continuous operation for 4 to 6 hours, measure the insulation resistance of the motor winding to ground with a megohmmeter, which should be greater than 0.5 megohms.

Shutdown test: Before restarting a pump that has been out of service for a long time, the insulation resistance needs to be retested.

Cable inspection: Regularly check if the cables are damaged or cracked. Reliable insulation should be wrapped around the joints to prevent leakage or electric shock accidents.

Protective devices: Ensure that devices such as leakage protection devices and thermal relays are sensitive and reliable to prevent safety hazards caused by overload or leakage.

Vi. Handling of Abnormal Situations

No water output or low water volume

Reasons: Incorrect steering, over-limit head, clogged filter screen, and worn seal.

Treatment: Change the phase sequence, replace the high-head pump, clean the filter screen, and replace the sealing parts.

The motor fails to start.

Reasons: Low power supply voltage, open circuit, impeller jamming, winding burnout.

Solution: Adjust the voltage to 342-418V, investigate the cause of the open circuit, remove debris, and conduct a major overhaul of the motor.

Abnormal vibration or noise

Reasons: Rotor imbalance, bearing wear, and deviation of the pump and motor shaft.

Handling: Send to the factory for repair, replace the bearings, and adjust the coaxiality of the motor and pump.

Vii. Storage and Long-term Maintenance

Dry storage: When the pump is not in use for a long time, lift it out of the water, wipe off the water stains, and hang it in a dry and well-ventilated room to prevent the motor from getting damp.

Winter protection: Before the wet submersible pump is stored in the warehouse, the lubricating cooling water inside the motor must be drained to prevent freezing and damage to the motor.

Regular start-up: During seasons with lower usage frequency, jog once a week to keep the impeller running smoothly.

Viii. Comprehensive Maintenance and Testing

Regular maintenance: Conduct a comprehensive inspection every two years, disassemble all components, clean and lubricate them, and then reassemble.

Air pressure test: After replacing the sealing box, use an air pressure of 0.2MPa to check whether there is any air leakage on the mating surfaces and sealing surfaces of each part to ensure the sealing performance.

Load test: After maintenance, conduct no-load current and load loss tests at rated voltage to ensure performance meets standards.

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