HI-TOPER Help You to Exclude the Small Faults of Centrifuge

Fault phenomenon:

Centrifuge is one of the important equipment in hospitals and research institutions, and it will have a direct impact on the quality of being centrifuged material. When I am repairing a centrifuge with a instability speed, and find whenever in high speed or low speed, both is instability.

Troubleshooting:

This centrifuge is a DC-type speed motor, and its speed is decided by adjustable resistance to change the conduction angle of SCR. Controlling the voltage arriving at the two ends of the motor. Then to reach the purpose of speed controlled. Motor speed instability, analysis from the principle, the following four cases are possible.

1.Adjustable resistance. As adjustable resistance installs on the control panel, using very high frequency. With the long time usage, then poor contact will be common occurs.

2.SCR also a lot of problems, usually short-circuit breakdown, pipeline pumps open, can not trigger or internal poor contact.

3.One is broken in the four rectifier diodes.

4.There is toner between motor rotor and commutator or brush is poor itself. With the repair principle of easy to hard. First, measure adjustable resistance, resistance value regular changes with adjustable. Then to prove potentiometer is good. And magnetic pump to show SCR also is good. When measure the four rectifier diodes, find one sometimes is good, sometimes is bad. With this dixde, one end is fastend on the circuit board by screw, the other end soldered to the board with a line, When removed from the board found that the positive and negative loosening, and then measuring the side while shaking, confirmed that the diode sometimes is good, sometimes is bad. sewage pumps can not see the tube model, put the same size pipe installation, turn on the power, speed quickly, just think of the tube breakdown, remove and measure is good.

5.Measure other three diode are goof. But when comparing the measured and found two types of diode polarity opposite (ie the end with the screw has a positive polarity, also is negative), so be sure to pay attention to when installing the best to use the same model, same specifications component, Chemical pump when replaced with the same type of component specifications, Turn on the power and test machine, everything is back to normal.