BBTRZ, whose full name is "Copper-core Flexible Mineral Compound Insulated Heavy-duty Fireproof Cable", is a second-generation mineral insulated cable product developed after the rigid BTTZ and flexible YTTW types. It adopts a composite structure of copper stranded conductor + mica tape/mineral compound insulation + mineral fireproof filling + low-smoke halogen-free flame-retardant outer sheath, without a metallic tube sheath. It achieves fire resistance through the "ceramization" characteristic of the mineral compound, making it the member of the mineral insulated cable family with the best flexibility, the most convenient installation, and relatively lower cost.
BBTRZ is currently mainly produced according to enterprise standards (which differs from YTTW, which already has a national standard), and references multiple national/international standards as normative basis:
-
Enterprise standards: Q/MD 22-2016, Q/CG 004-2017, Q/WHJH01-2019, etc. (each manufacturer has its own enterprise standard)
-
GB/T 12706.1-2020 "Power cables with extruded insulation and their accessories for rated voltages from 1kV (Um=1.2kV) up to 35kV (Um=40.5kV) — Part 1: Cables for rated voltages of 1kV and 3kV"
-
GB/T 19666-2019 "General rules for flame retardant and fire resistant wires and cables or optical fiber cables"
-
BS 6387:2013 "Method for specification of performance requirements for cables required to maintain circuit integrity under fire conditions"
-
BS 8491:2008 "Method for assessment of fire integrity of large diameter power cables"
-
IEC 60331 Tests for fire-resistant cables
-
GB/T 18380 series "Tests on electric and optical fibre cables under fire conditions"
-
GB/T 17651 "Measurement of smoke density of cables or optical fibre cables burning under defined conditions"
