1. BTTZ cable is a copper core, copper sheathed, magnesium oxide insulated, fire-resistant cable. BTTRZ is a copper core, inorganic mineral tape-wrapped, copper sheathed, flexible fire-resistant cable.
2. BTTZ is not flame retardant; BTTRZ is a flame-retardant copper core cable.
3. BTTZ is less flexible than BTTRZ.
BTTZ cable (copper core, copper sheathed, magnesium oxide insulated, fire-resistant cable) is a new type of cable with a seamless copper tube outer sheath, a core filled with magnesium oxide crystal powder as insulation, and a single-strand copper rod conductor. It is heat-resistant, fireproof, explosion-proof, and non-combustible (it can operate continuously for long periods at 250°C and even for short periods of 30 minutes at extreme temperatures of 1000°C). It also features a high current carrying capacity, a small outer diameter, high mechanical strength, and a long service life. It generally does not require a separate grounding conductor. It is widely used in hazardous, harsh, and high-temperature environments such as nuclear power plants, metallurgy, chemical industry, mines, and kilns. In recent years, it has also been increasingly used in high-rise buildings, airports, docks, subways, and other locations to ensure uninterrupted operation of firefighting power and other critical equipment, including fire pumps, fire elevators, local lighting, emergency evacuation signs, security cameras, fire alarms, smoke exhaust systems, and self-contained power supplies in the event of a fire. However, BTTZ cable installation is the most complex, takes the longest time, and suffers from numerous limitations.
BTTRZ (copper core inorganic mineral insulated tape wrapped insulated copper sheathed flexible fire-resistant cable) is manufactured using a similar process to BTTZ cable, except that the cable offers a degree of flexibility:
① It can be wound on a cable drum, preventing damage during transportation;
② It facilitates on-site installation;
③ Once energized, it is immune to damage from natural forces (thermal expansion and contraction) and electrodynamic forces. BTTRZ cable can replace BTTZ cable and is currently widely used due to its flexibility and ease of transportation and installation.
