Laboratory instruments are generally best maintained once every three months, especially for some precision instruments. If it is an instrument with a rechargeable battery, charge it once every three months to avoid battery damage. Different instruments have different methods of maintenance. Take measures against dust, shock, and corrosion according to different characteristics. For details, refer to the maintenance instructions and frequency of use in the instruction manual of each instrument.
One. Ten principles of electrical equipment maintenance
1. Move your mouth first
For faulty electrical equipment, do not respond to the emergency first, you should first ask before and after the failure and the phenomenon of the failure. For unfamiliar equipment, you should also be familiar with the circuit principle and structural characteristics, and follow the corresponding rules. Before disassembly, you should be fully familiar with the function, location, connection method and relationship with other surrounding components of each electrical component. In the absence of an assembly drawing, you should draw the sketch while disassembling it, and mark it.
2. First outside then inside
The equipment should be checked for obvious cracks and defects, and its maintenance history, service life, etc. should be checked before the inside of the machine is checked. Before dismantling, you should line up the surrounding failure factors, and you can only dismantle after determining that it is an internal failure. Otherwise, blindly dismantling, the equipment may be repaired and worsened.
3. Mechanical first
Only after confirming that the mechanical parts are not faulty, do electrical inspection. When checking circuit faults, you should use testing equipment to find the faulty part, confirm that there are no bad contact faults, and then check the operating relationship between the line and the machine to avoid misjudgment.
4. Static first dynamic
判断 When the equipment is not powered on, judge the quality of the electrical equipment buttons, contactors, thermal relays and fuses to determine the location of the fault. Power on test, listen to its sound, measure parameters, judge failure, and finally perform maintenance. For example, in the absence of phase of the motor, if the three-phase voltage value cannot be distinguished, you should listen to it and measure each phase voltage separately to determine which phase is defective.
5. Clean after repair
For heavily polluted electrical equipment, first clean its buttons, wiring points, and contact points, and check whether external control keys have failed. Many faults are caused by dirt and conductive dust blocks, and faults are often eliminated once cleaned.
6. Power first, then equipment
The failure rate of the power supply part accounts for a high proportion of the entire faulty equipment, so it is often more efficient to repair the power supply first.
7. First universal then special
故障 Faults caused by the quality of assembly parts or other equipment failures generally account for about 50% of common failures. The special faults of electrical equipment are mostly soft faults, which rely on experience and instruments to measure and repair.
8. First outside then inside
Don't rush to replace damaged electrical components first, and consider replacing damaged electrical components when confirming that the peripheral device circuit is normal.
9. DC first then AC
During maintenance, the static operating point of the DC circuit must be checked before the dynamic operating point of the AC circuit.
10. Fault after debug