I. Applicable Scope
The LSMN series fire-resistant busway is suitable for power distribution systems rated at 690V or below, with rated working currents of 250～5000A and frequencies of 50～60Hz. After years of testing and industrial operation, its electrical, fire-resistant, and metallic structural properties have reached the advanced level domestically.
Section II: Structural Performance
1. Utilizing a reasonable "sandwich" phase-line closely stacked structure design, the busbar channel is compact in shape and has a small volume. The busbar system boasts advantages such as low impedance, reduced voltage, and excellent dynamic and thermal stability.
2. The housing is composed of cold drawn thin steel profiles. The side panels are our double-layered honeycomb structure, effectively preventing high-temperature gases or open flames from directly entering the busway interior. The surface of the busway housing is galvanized and coated with fire-retardant paint (the paint expands rapidly at a geometric rate on the busway surface when exposed to fire, forming a dense carbonized insulating layer, sealing all gaps in the busway housing to prevent high temperatures from entering the interior).
3. Joints utilize specialized fire-resistant insulation components for reliable and convenient connections.
Section 3: Insulation Configuration
The LSMN series fire-resistant busway uses insulation supports as its main insulating medium, with alumina high-temperature ceramic components selected, capable of withstanding temperatures up to 1000°C. The copper busbars are insulated using a blend of polyimide and high-temperature mica powder tape winding. (Polyimide, commonly known as the "gold tape," is an advanced insulating material in the electrical industry, with good high-temperature and dielectric properties; dielectric strength ≥ 22000V, no toxic gases are emitted at high temperatures; the mica powder tape can withstand fire temperatures up to 960-1000°C for 1.5 hours, meeting the A-class requirements as per IEC 371-3-8 and GB 12666.6 fire resistance tests.)
IV. Main Technical Parameters
1. Utilizes a "sandwich" sealing structure, with a general protection rating of IP54.
2. The busbar system can withstand a working frequency withstand voltage of 3750V, with no breakdown or flashover occurring within 1 minute.
3. The busbar system, when operating under long-term rated current, will not exceed a temperature rise of +60K at the connection terminals, +30K on the metal housing, and +40K on the surface of the insulating components within the slots.
4. The busbar tray system can maintain normal operation even after a fire, when the combustion temperature reaches 960°C.
