How to solve the problem of reduced or no coolant flow in mechanical seal of sander?

March 12,2020

How to solve the problem of reduced or no coolant flow in the mechanical seal of the sander?

A. Reduced coolant flow

1. The impurities in the cooling liquid are adsorbed on the oil inlet filter by the electric oil pump, which makes it difficult to enter the oil and reduces the oil output.

Solution: Open the cover above the sander machine base, lift the electric oil pump inlet pipe out of the fuel tank, and remove the debris on the filter screen.

B. No cooling fluid sprayed out of the oil hood above the base.

1. Electric oil pump does not work (no vibration of the oil pump)

A. The plunger in the electric oil pump is stuck by impurities in the oil and cannot be moved (the moment you touch the electric oil pump when you just turn on the pump, you can feel the electric oil pump electromagnet move, and then there may be very slight vibration without movement)

Solution: Remove the oil hood end of the electric oil pump, and observe whether the plunger is stuck and cleaned.

B. The electronic components in the electric oil pump are damaged (at this time, the power indicator of the electric oil pump is red)

Solution: Replace the pump or repair the electronic circuit part of the pump.

C.24V DC air switch protection in the electrical box (at this time, the solenoid valve does not operate and there is no sound)

Solution: Check the solenoid valve and electric oil pump for a short circuit.

D.24V DC stabilized switching power supply has no output, the green indicator light on the stabilized switching power supply is off

Solution: Check whether the 220V AC air switch is protected? Is the main motor thermal relay overcurrent protection activated?

If it starts (at this time, the two normally-connected terminals under the red button of the thermal relay have been connected, and one of them has no 220V,

(Both terminals are charged when normal.) Press it, or it will automatically recover after waiting for half an hour.

2. The electric oil pump can move (the electric oil pump trembles) and cannot circulate the coolant

Solution: The oil inlet filter is blocked or the check valve in the electric oil pump does not work. Clean the filter or check valve in the oil pump.