Engineering machinery electrical control system maintenance precautions - Solutions - Huaqiang Electronic Network

As the electrical systems in construction machinery become increasingly complex, even minor oversights during maintenance can lead to small issues turning into major failures, causing significant financial losses. Here are some important notes to consider:

1. Always disconnect the power supply first

Before working on any wiring or connectors, it is essential to turn off the main power supply of the equipment. Failing to do so can result in damaged wiring harnesses, blown fuses, or even short circuits that may cause serious damage.

2. Identify wire colors accurately

Imported construction machines often use color codes to distinguish different wires. The letter on the left represents the background color, while the letter on the right indicates the wire's color. For example:

Code Color Table:

R - Red | W - White

L - Blue | G - Green

O - Orange | Lg - Light Green

Y - Yellow | B - Black

Br - Brown | P - Pink

Gr - Gray | V - Violet

3. Properly connect and disconnect terminal connectors

(1) When removing a connector, hold the connector itself, not the wire. Release the locking mechanism before pulling it apart.

(2) When dealing with waterproof connectors, ensure no water enters the connector. If water gets inside, dry it thoroughly before reconnecting.

(3) Before connecting terminals, avoid bending or extending them. If there is rust, sand it off before installation.

(4) Make sure you hear a "click" when securing the connector with a lock.

4. Use circuit testing instruments correctly

(1) Understand the operation of the instrument before using it. Avoid improper usage that could damage the device.

(2) When measuring voltage or current, select the appropriate range to prevent damage to the meter. Always measure voltage and current carefully to avoid short circuits.

(3) Before starting measurements, check the terminal positions based on the schematic diagram. If the connector is too small, wrap a thin wire around the probe for better access.

5. Understand the electrical schematic diagrams

Electrical schematics show how components interact and operate. Understanding these diagrams helps identify faulty parts quickly, avoiding unnecessary disassembly and saving time during repairs.

6. Recognize different types of ground connections

The negative terminal of the battery is one type of ground. Since most construction machinery uses negative grounding, the body of the machine also acts as a ground. A good grounding connection allows both grounds to be treated as one. However, with modern electronics and microprocessors, additional ground points may exist, usually relative to the microprocessor’s power supply. It's crucial to know which ground reference you're using during testing.

7. Keep detailed records for future reference

During electrical system overhauls, many parameters may be measured. Keeping accurate records ensures that no data is lost and provides a valuable historical reference for future troubleshooting and analysis.

8. Handle wiring harnesses with care

Avoid sharp bends or folds when tying up cables. Keep the harness away from moving parts to prevent wear or breakage. Also, keep it away from oil and water to maintain its integrity.

9. Repair or replace worn wires promptly

If you notice any damage or wear on the wires, repair them immediately using waterproof tape. This helps prevent further deterioration and potential electrical faults.

10. Use fuses properly

Always replace a fuse with one of the same specification. In an emergency, if you need to substitute, use the thinnest possible copper wire to limit the risk of further damage in case of a fault.