Fire-resistant Low-voltage Enclosed Busway

Selection of insulation and refractory materials with excellent performance

• The mica tape wound by the copper row of busway conductor conforms to JB/T5019~20 "electrical insulation mica products" and JB/T6488-1~3 "mica tape" standards. The mica tape has good flexibility and high heat resistance and good dielectric properties and mechanical properties under normal condition: bending strength ≥180MPa; dielectric strength ≥35kV/mm; volume resistivity >1010Ω-m. When the temperature reaches 600℃, the mica tape still has high insulation performance insulation resistance >10MΩmm2.
• According to the different fire resistance limit of the refractory busway, the measures taken by the heat insulation layer are also different. If the busway needs to run for a long time with electricity, the heat insulation layer is usually directly insulated with air so as not to affect the heat dissipation during the operation of the busway, and when the busway is not normally energized for emergency power use only, its heat resistance limit is higher and the heat insulation layer needs to be filled with silica wool, the silica wool material selected for this refractory busway conforms to GB3003 "common aluminosilicate refractory fiber mat" standard, its AL2O3+SiO2 content reaches 96%, the continuous use temperature is 1050℃, ^high use temperature reaches 1250℃.
• When the fire occurs within 3~5 minutes, the coating starts to foam and expand, forming a heat insulation layer, and the thermal conductivity increases rapidly, which effectively reduces the heat transfer. All the performance indexes of the refractory coating used in this refractory busway are in accordance with the national GB14907-94 standard.
• In order to meet the refractory requirements, the phase separation block and the joint separation block are made of high temperature resistant ceramic material, which has an Al2O3 content of more than 95% and has the following dielectric and mechanical properties under normal conditions: dielectric strength ≥13kV/mm volume resistivity >20MΩ-cm flexural strength ≥250MPa. the ceramic is particularly effective in temperature resistance, and the measured insulation resistance is >10MΩ when the temperature reaches 900°C. Due to the good stability of the ceramic, there is no aging problem of the insulation material, thus effectively extending the service life of the busway.
• Environmentally friendly products: In case of fire, no toxic gas is emitted from the busway, and no secondary combustion is formed, which is a new generation of environmentally friendly electrical products.
• Flexible wiring: The busway plug interface is set flexibly, and it is convenient to draw out the branch current. Each plug interface can be inserted into different capacity plug boxes, and the plug box pin guard is also made of high temperature resistant ceramic material to ensure that the power can be drawn out smoothly in case of fire.
• NHCCX series refractory busway has successfully passed the type test of National Electric Control Equipment Quality Supervision, Inspection and Testing Center and the refractory test of National Chemical Building Material Testing Center, and its electrical performance, mechanical performance and refractory performance are all at the domestic ^ level according to the investigation.