FZN25/FZRN25-12 Indoor Vacuum Load Switch Installation and Maintenance Guide
1. Installation steps
Preparation before installation
Inspect equipment: confirm that the switch has no damage on the appearance, no cracks in the vacuum interrupter, and the operating mechanism is flexible.
Check parameters: ensure that the rated voltage (12kV) and current of the switch match the system.
Tool preparation: torque wrench, level, insulation tester, etc.
Installation and fixation
Switch cabinet adaptation: Install on the fixed bracket of standard switch cabinets such as XGN15 and KYN28, and tighten with bolts (torque refers to manufacturer requirements, usually 30~50N·m).
Horizontal correction: Use a level to adjust the switch position to ensure that the operating mechanism is not tilted.
Electrical connection
Main circuit wiring: When connecting the busbar or cable, ensure that the contact surface is clean, apply conductive paste, and tighten the bolts (avoid deformation caused by overtightening).
Grounding connection: reliable grounding (grounding resistance ≤4Ω).
Operating mechanism debugging
Manual operation test: manually open and close the switch 3~5 times, check whether the energy storage and release are smooth, and confirm that the opening and closing position indication is correct.
Electric operation (if optional): Connect the control power supply (DC220V/AC220V) and test the remote opening and closing function.
Interlock verification
Ensure that the mechanical interlock with the grounding switch and cabinet door is effective (for example: the grounding switch cannot be operated when the load switch is closed).
2.Maintenance points
Regular inspection items
| Inspection content | Standard/method | Cycle |
|---|---|---|
| Vacuum interrupter appearance | No cracks, discharge marks | 1 year/after failure |
| Main circuit contact resistance | ≤50μΩ (measured with a micro-ohmmeter) | 1~2 years |
| Operating mechanism lubrication | Apply low-temperature grease (such as molybdenum disulfide) | 2 years or 3000 operations |
| Insulation performance | Power frequency withstand voltage test (42kV/1min) | 3 years |
| Fuse (FZRN25) | Check whether the fuse is blown and the contact is good | Half a year or after failure |
Key maintenance operations
Vacuum detection: If the vacuum is suspected to be reduced, it is necessary to judge by a withstand voltage test or a professional vacuum detector.
Replace the fuse:
Operate after power off and power test.
Replace the same type of fuse (such as XRNT-12).
It is strictly forbidden to use fuses of different specifications in parallel.
Common troubleshooting
| Fault phenomenon | Possible cause | Solution |
|---|---|---|
|
Switching stuck |
The mechanism lacks lubrication or the bolts are loose |
Clean, lubricate, and tighten bolts |
|
Vacuum interrupter discharge |
The vacuum degree decreases or the insulation ages |
Replace the arc extinguishing chamber |
| Frequent fuse blowing | The short-circuit current exceeds the standard or the selection is wrong | Check the system short-circuit capacity and replace the fuse |
3.Safety precautions
Power must be turned off during operation: disconnect the power supply and test the power before maintenance, and hang a "no closing" sign.
No load operation: The isolation knife switch is only used for no-load separation and closing, and the load switch must be disconnected first.
Professional personnel: High-voltage operations such as withstand voltage tests must be certified before work.
If you need further communication or consultation, you can contact me :
📧 Email: pannie@hdswitchgear.com.
📞 Phone: +8618789455087
