FZN21‑12D/T630‑20 Indoor Vacuum Load Switch‑Fuse Combination Unit

Overview

Models FZN21‑12D/T630‑20 and FZN21‑12DR/T125‑31.5 high‑voltage vacuum load switches and combined units are applied in 3‑phase AC 12 kV, 50 Hz power distribution systems. Featuring compact structure, small size, light weight, long service life, strong making‑and‑breaking capacity, high safety and reliability. When used together with fuses (referred to as combination units), they can replace higher‑cost circuit breakers, with simple and convenient operation and maintenance.

Structural Features

FZN21‑12 series load switches and combined units mainly consist of frame, disconnector (or fuse acting as disconnector), vacuum interrupter, earthing switch and operating mechanism.

This product features compact layout, small dimension, long service life, excellent making‑and‑breaking performance, easy operation and maintenance.

Equipped with motor‑driven operating mechanism and energy‑storage springs, the vacuum switch enables fast closing and opening operations. Interlocks are provided among the disconnector, vacuum switch and earthing switch to prevent mis‑operation.

Operating Conditions

• Altitude: ≤ 1000 m;
• Ambient temperature: -25 ℃ ~ +40 ℃;
• Relative humidity: daily average ≤95 %, monthly average ≤90 %;
• No conductive dust, corrosive gas or water‑vapor;
• No fire or explosion‑hazardous atmosphere;
• No severe vibration; installation inclination angle less than 3°.