Fuse cut-out with striker VVT-D3 12kV/125A 004232018

Reliable medium voltage protection

VVT-D3 12kV/125A fuse link is an element designed to protect medium voltage (MV) electrical and power equipment – lines, cables, transformers, motors, and capacitor banks. It provides effective protection against the effects of thermal and dynamic short circuits, and thanks to the built-in thermal release, also against uncontrolled temperature increases.

Design and application

Fuse links from the VV series, including the VVT-D3 model, are characterized by a solid construction and reliability confirmed by technical reports from tests conducted by KEMA Labs. Equipped with a thermal release, they trigger a disconnector with a force of 80N when the temperature of the fuse link body reaches approximately 120°C – regardless of the heat source. This is an important solution, especially in SF6 gas switchgear, where traditional protection may fail.

It is worth paying attention to several key structural elements:

• High-strength ceramic tube: provides insulation and resistance to environmental conditions.
• Galvanically protected contacts: minimize the risk of corrosion and ensure a stable connection.
• Caps made of nickel-plated electrolytic copper: guarantee good conductivity and durability.
• Fuse element made of silver: ensures precise operation and a quick response to overload.
• Reliable sealing system: protects against moisture and external factors.

Parameters and performance

The VVT-D3 12kV/125A fuse link has a rated short-circuit breaking capacity of 63 kA, which guarantees effective circuit interruption in the event of a short-circuit current. The minimum breaking current is 450A, which means that the fuse link will operate correctly even at relatively low overload current values. The cold resistance is 5.2 mΩ and the power loss is 138W. The minimum arc integral I²t min is 55000 A²s and the maximum I²t max is 300000 A²s. The diameter of the fuse link is 85mm and the length is 292mm with a weight of 4kg. The rated voltage AC is 6/12kV and the rated frequency is 50/60Hz.