Product description
In addition to the advantages of insulated busbars in electrical performance, NHMC fire-resistant busbars have unique fire-proof performance. The conductive materials are made of high-quality conductive copper bars, the insulation is made of mica and high-strength ceramic materials, and the busbar shell is double-layered. It is treated with fireproof materials inside and outside. The busway can work continuously for no less than 90 minutes when the ambient temperature rises to 960 °C. It is non-toxic, non-polluting and can prevent water penetration during fire fighting.
Scope of application
The NHMC type fire-resistant busway is suitable for transmission and distribution systems with rated voltage below 690V, rated working current of 250A-6300A and frequency of 50-60HZ. This series of busbars is a new type of fire-resistant busbar designed on the basis of the CMC busbar and combined with the actual situation in China. After years of trials, trial production and industrial trial operation, its electrical, fire resistance and metal structure have reached the domestic advanced level.
Structural features
It has the same “sandwich” phase line compact laminated structure design as the “CMC series”. The busbar slot has compact shape and small volume. The busbar system has the advantages of low impedance, low voltage, good dynamic thermal stability, and no chimney in case of fire. The effect is formed.
The outer casing is a mixture of cold drawn and thin steel profiles. Its two side panels are our company’s original double-layer hollow structure. The sealed hollow effectively prevents high temperature gas or open flame from directly entering the inside of the busbar. The surface of the busbar shell is galvanized and sprayed with fire-retardant coating. (In case of fire, the coating can rapidly expand on the surface of the busbar to form a dense carbonized thermal insulation layer at a geometric speed. Seal all the gaps in the busbar casing to prevent high temperature from directly entering the inside of the busbar.)
The joints are made of special refractory insulation components, which are reliable and convenient to connect.
Insulation configuration
The NHMC series busbar refractory insulation medium mainly adopts aluminum alloy high temperature ceramic parts with insulation support, which can withstand high temperature up to 1000 °C. The busbar copper conductor insulation is mixed and entangled with polyimide and high temperature resistant mica tape. (Polyurethane, commonly known as the gold belt, is the most advanced insulation material in the electrical industry. It has good high temperature resistance and dielectric properties, dielectric strength ≥ 22000V, no toxic gas release at high temperature; powder mica belt has high refractory temperature 960-1000 ° C / 1.5 hours, according to IEC371-3-8, GBl2666.6 fire resistance test to meet Class A requirements.)
Technical Parameters
Designed with a “sandwich” seal, the general protection rating is IP54.
The busbar system can withstand a power frequency withstand voltage of 3750V, and there is no breakdown flashover in 1min.
When the busbar system works normally at rated current, the temperature rise is not higher than: 60K at the joint, 30K at the outer casing, and 40K at the inner tank.
The busway system has a combustion temperature that rises to 960 °C after a fire. Still able to maintain normal operation.
Cross-sectional schematic
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