Scope of Application

The FN12-12D/630-20 Type Indoor AC High-Voltage Load Switch is a three-phase high-voltage switchgear with a rated voltage of 12kV and a rated frequency of 50Hz. It is designed to switch on and off load current, loop current, no-load transformers and cable charging current, as well as to close short-circuit current. The load switch equipped with an earthing switch is capable of withstanding short-circuit current.

The FN12-12(R)D/125-31.5 Type Indoor AC High-Voltage Load Switch-Fuse Combination Device is an indoor high-voltage switchgear integrated with the FN12-12D Load Switch and the high-voltage current-limiting fuse. It can interrupt any current up to the short-circuit current: the load switch interrupts the working current, the fuse interrupts the short-circuit current, and they jointly interrupt any current between the working current and the short-circuit current. Meanwhile, the fuse trips the load switch via its striker.

The FN12-12(R)D is mainly used in urban distribution stations with three-phase ring network terminal power supply and industrial electrical equipment, serving for load control and short-circuit protection. As the combination device provides more reliable protection for electrical equipment such as transformers than circuit breakers, it is particularly suitable for ring networks, dual radial power supply units and compact secondary substations.

◎ When the FN12-12 is installed in the load switch cabinet, the busbar connection is extremely convenient without any bending or processing.

◎ The interruption is performed inside the bell-shaped insulator; free gas is contained, and phase-to-phase insulation remains unaffected.

◎ An isolating fracture is formed when the switch is open, and a visible break can be observed through the inspection window.

◎ The adoption of a transparent observation cover enhances the dustproof effect.

◎ The operating sequence of load switch → earthing switch → cabinet door is realized by mechanical interlocks to meet the anti-misoperation requirements.

Normal Service Conditions

Altitude: ≤1000m

Ambient Temperature: upper limit +40℃; lower limit -25℃ (storage and transportation at -30℃ is allowed)

Daily average relative humidity: not exceeding 95%

Monthly average relative humidity: not exceeding 90%

Seismic Resistance: seismic intensity not exceeding Degree 8

No locations with violent vibration, shock, fire hazard, chemical corrosion or explosion risk

Pollution Degree: Class Ⅱ