27KV Export Type Drop-out Fuse, Outdoor High-Voltage Short-Circuit Protection and Load Break Switch

Product Overview

The 27KV drop-out fuse is a critical outdoor high-voltage protection device specifically designed for 10kV distribution systems. It is typically installed on the high-voltage side of 10kV distribution transformers or on branch trunk lines of distribution lines, serving as a common and reliable short-circuit protection switch for short-circuit and overload protection of transformers and lines, as well as for making and breaking load currents. This 27KV drop-out fuse consists of two main parts: an insulating support and a fuse tube. The fixed contacts are installed at both ends of the insulating support, while the moving contacts are installed at both ends of the fuse tube. The fuse tube has a unique structure, composed of an inner arc-extinguishing tube and an outer epoxy fiberglass tube, ensuring efficient arc extinction. For load-break drop-out fuses, resilient auxiliary contacts and an arc chute are also added specifically for safely making and breaking load currents.

Installing the 27KV export type drop-out fuse on branch lines of 10kV distribution lines effectively limits the scope of power outages during faults. Because it provides a clearly visible disconnection point, it also functions as a disconnector, creating an absolutely safe working environment for line and equipment maintenance, greatly enhancing the safety of maintenance personnel. When installed on a distribution transformer, it can serve as the primary protection device for the transformer. As a result, the 27KV drop-out fuse has been widely applied and popularized in 10kV distribution lines and distribution transformers. It is characterized by economy, practicality, convenient operation, and strong adaptability to harsh outdoor environments, and is widely used on the primary side of 10kV distribution lines and distribution transformers as a core protection component and for equipment switching operations.

During normal operation, the fuse tube of the 27KV export type drop-out fuse is held in the closed position by the tension of the fuse element. When a fault occurs in the system, the large fault current causes the fuse element to melt rapidly, creating an arc. At this time, the arc-extinguishing tube, subjected to the high temperature of the arc, decomposes a large amount of gas, creating high pressure inside the tube and forming a strong longitudinal blowing effect, which rapidly elongates and completely extinguishes the arc. After the fuse element melts, the lower moving contact loses tension and flips downward, and the locking mechanism releases the fuse tube, causing it to drop and form a clearly visible disconnection position. When load-break operation is required, an insulating pole can be used to operate the contact. During the initial phase of operation, the main contacts separate while the auxiliary contacts remain in contact. As the insulating pole is pulled further, the auxiliary contacts also separate, creating an arc between them. This arc is elongated in the narrow slot of the arc chute, and the arc chute material generates gas, reliably extinguishing the arc at current zero, completing the interruption of the load current.

Installation Position Diagram

Main Technical Parameters

The following are the main technical parameters of the 27KV drop-out fuse for reference in selection and design.

15KV-27KV

Rated voltage (kv)	Rated current (A)	Breaking current (A)	Impulse voltage (BIL)	Power-frequency voltage	Leakage distance (MM)	Weight (KG)	Dimensions (CM)
12	100	6300	110	40	250	6.5	40×36×11.5
12	200	10000	110	40	250	6.5	40×36×11.5

15KV-27KV

Rated voltage (kv)	Rated current (A)	Breaking current (A)	Impulse voltage (BIL)	Power-frequency voltage	Leakage distance (MM)	Weight (KG)	Dimensions (CM)
15	100	8000	125	45	320	7.5	50×36×12.5
15	200	12500	125	45	320	7.5	50×36×12.5

24KV-27KV

Rated voltage (kv)	Rated current (A)	Breaking current (A)	Impulse voltage (BIL)	Power-frequency voltage	Leakage distance (MM)	Weight (KG)	Dimensions (CM)
24	100	8000	150	65	540	10	50×36×16
24	200	10000	150	65	540	10	50×36×16

33KV-36KV

Rated voltage (kv)	Rated current (A)	Breaking current (A)	Impulse voltage (BIL)	Power-frequency voltage	Leakage distance (MM)	Weight (KG)	Dimensions (CM)
33	100	10000	170	70	720	15	64×35×18
33	200	12500	170	70	720	15	64×35×18

The 27KV export type drop-out fuse is strictly designed and manufactured in accordance with the national standard GB/T 15166.2, ensuring its protection performance and mechanical reliability in 10kV distribution systems. As an economically efficient outdoor high-voltage protection switch, it continues to guarantee the safe and stable operation of power grids with its clear disconnection point, reliable short-circuit breaking capacity, and convenient operability.