Scope of Application

The FZN25-12D Type Indoor AC High-Voltage Vacuum Load Switch and FZRN25-12D Type Indoor AC High-Voltage Vacuum Load Switch-Fuse Combination Device are control and protection devices for three-phase AC 50Hz, 12kV power distribution systems. They are widely used in power distribution stations of industrial and mining enterprises, urban buildings, and other locations. Compared with circuit breakers, the combination device offers more reliable protection and operation for electrical equipment such as transformers, and is particularly suitable for ring networks, dual radial power supply units, and compact secondary substations.

Service Environmental Conditions

Altitude: ≤1000m

Ambient air temperature: upper limit +40℃, lower limit -25℃ (storage and transportation at -30℃ is allowed)

Relative air humidity: daily average ≤95%, monthly average ≤90%

Seismic resistance: seismic intensity not exceeding Degree 8

The surrounding air shall be free from obvious pollution by corrosive or flammable gases, water vapor, etc.

No frequent violent vibrations

Pollution degree: not exceeding Class Ⅱ

Structural Characteristics

◎ This product adopts a vacuum interrupter for arc extinguishing, featuring stable and reliable performance, long electrical life, high breaking times, strong making and breaking capacity, and simple operation and maintenance.

◎ Integrating the switch body with the operating mechanism, and combining the isolating switch, load switch, and earthing switch into one unit, it boasts a compact structure and small size.

◎ The direct-acting isolating fracture and vacuum interrupter are arranged in series, with high dynamic and thermal withstand current parameters; the unique linkage according to the specified operation procedure enables one-time completion of operations.

◎ The conical static contact, insulation cover, and shutter structure completely separate the busbar from the load switch unit.

◎ The vacuum load switch, earthing switch, shutter, and switch cabinet door are equipped with strict "five-prevention" mechanical interlocks to prevent misoperation, ensuring safety and reliability.

◎ The spring energy storage type operating mechanism supports both electric and manual opening/closing, facilitating the realization of three remote control requirements (remote control, remote signaling, remote measurement).

◎ The opening/closing operating power supply is compatible with both AC and DC.

◎ The manual opening/closing operation is conventionally located on the right side of the load switch; left-side operation can also be provided according to user requirements, and the operation panel can be extended.

Adopted Standards

GB 3804-2004 "AC High-Voltage Load Switches for 3.6kV～40.5kV"

GB 16926-2009 "AC High-Voltage Load Switch-Fuse Combination Devices"

IEC 265-1 "High-Voltage Load Switches - Part 1: High-Voltage Load Switches with Rated Voltage Above 1kV and Below 52kV"

IEC 420 (1990) "High-Voltage AC Load Switch-Fuse Combination Devices"