What tools are used for low-voltage switchgear maintenance?

Tools used for low-voltage switchgear maintenance mainly include dry soft cloths, vacuum cleaners, megohmmeters, torque wrenches, insulating gloves, and insulating boots. These tools each play a specific role in daily inspections and periodic maintenance, and are crucial for ensuring operational safety and stable equipment operation. Proper use of these tools can effectively identify potential hazards, prevent faults, and extend the service life of the switchgear.

 

Commonly Used Maintenance Tools and Their Functions

Dry Soft Cloths and Vacuum Cleaners

Purpose: To remove dust and stains from the inside and outside of the switchgear, paying particular attention to cleaning the ventilation holes, busbars, and insulator surfaces.

Precautions: Avoid using wet cloths or corrosive cleaning agents to prevent short circuits or material damage; the vacuum cleaner should be a static-free type to avoid generating electric sparks.

 

Megohmmeter (also known as a megohmmeter)

Purpose: To measure the insulation resistance between phases and to ground in the main circuit to determine if the insulation is aging or damp.

Standard Value: Insulation resistance should be ≥1 MΩ; values ​​below this value require investigation and handling.

Operating Instructions: Power must be disconnected and discharged before testing, and the equipment under test must be confirmed to have no voltage.

 

Torque Wrench

Purpose: Used to tighten busbar connection bolts, cable joints, etc., ensuring good contact and preventing overheating due to loosening.

Standard Example: The torque for Schneider BloKseT cabinet connection bolts is 40 N·m for M12 bolts, requiring calibration with a torque wrench.

Advantages: Avoids the risks of "overtightening and damaging threads" or "over-loosening and overheating."

 

Insulating Gloves and Boots

Purpose: Personal protective equipment to prevent electric shock accidents.

Withstand Voltage Rating: Should be ≥10kV, suitable for low-voltage cabinet operating environments.

Inspection Cycle: Insulating gloves and boots must undergo a power frequency withstand voltage test every six months to ensure reliable performance.

 

Multimeter

Purpose: To test the voltage, current, and resistance of control circuits and troubleshoot open or short circuit faults.

Usage Guidelines: Connect in parallel when measuring voltage, and in series when measuring current to avoid damaging the instrument due to incorrect connection settings.

 

Infrared Thermometer

Purpose: Non-contact detection of temperature at busbar connection points, circuit breaker contacts, etc., quickly identifying abnormal heating points.

Judgment Criteria: Normal operating temperature generally does not exceed 40℃; if it exceeds this, the load or contact status must be checked.

 

Electrical Tester

Purpose: To confirm that equipment has no voltage after a power outage; a life-saving tool for personal safety.

Before Use: Must be tested on known live equipment to ensure its normal operation.

 

Sandpaper (Fine Grit)

Purpose: To lightly polish the oxide layer on contacts to restore good conductivity.

Caution: Do not use coarse sandpaper to avoid damaging the contact surface.

 

Flashlight (High-Brightness LED)

Purpose: Provides illumination for easy observation of the cabinet structure, wiring status, and any abnormal traces.

Requirements: High brightness and long battery life to ensure clear visibility in dim environments.