Flexible Mineral Insulated Fire Resistant Cable

1. Introduction
Mineral Insulated Fire Resistant Cable with the fire resistance than A Grade, is also called “super A” fire resistance cable. Mineral Insulated Fire Resistant Cable can be divided into Rigid Mineral Insulated Fire Resistant Cable and Flexible Mineral Insulated Fire Resistant Cable.
Rigid Mineral Insulated Fire Resistant Cable is the traditional Mineral Insulated Fire Resistant Cable (BTT type Inorganic Magnesium Oxide Insulated, Copper Tube Sheathed), which has the weakness of big hardness, small length, difficult installation and so on.
Flexible Mineral Insulated Fire Resistant Cable is a new R&D product based on the performance combination of traditional Rigid Mineral Insulated Fire Resistant Cable and Organic Fire Resistant Cable, which is boasting of flexible structure, large length, easy installation and so on.
Our products are widely used in 0.6/1kV power supply system of places that are densely populated and have requirements of environment protection and fire resistance such as high buildings, hotels, supermarkets, hospitals, stations, airports, subways, tunnels, large public entertainment places, public transportation facilities, nuclear stations , military facilities, mining, chemistry, medicine, iron&steel, metallurgy, ship-building industries and so on, especially for the power supply to fire alarming device, communication device, smoking discharge equipment and emergent lighting system. In case of fire, the cable not only guarantees normal power supply within 180 minutes, but also control smoke toxicity without second harm to human.
 
2. Construction Diagram

                                            YTSY 5 Cores cable

 1. Copper conductor
2. Mineral insulation layer
3. XLPE insulation layer
4. Mineral filler
5. High flame retardant tape
6. Low smoke halogen free high flame retardant outer sheath

                                                    YTSLY,YTSGY 5 Cores Cable

This product boasts of its flexible structure, large length, no joint, easy installation, economical investment, long life and no pollution to the environment, it is especially applicable to the places that require large length power supply and fire resistance, its fire resistance can reach the Rigid Mineral Insulated Fire Resistant Cable (Magnesium Oxide insulated, Copper tube sheathed)

Type and name 

Executive Standard
The executive standard of Flexible Mineral Insulated Fire Resistant Cable. This product follows enterprise standard Q/EAAE 0272-2015 Flexible Mineral Insulated Fire Resistant Cable, the normative references include: IEC 60502-2014 Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1.2 kV) up to 30 kV (Um = 36 kV), BS 6387-2013 Test method for resistance to fire of cables required to maintain circuit integrity under fire conditions, IEC61034 Measurement of smoke density of cables burning under defined conditions, GB/T 3048 Test methods for electrical properties of electric cables and wires
 
Fire resistance of YTSY, YTSLY and YTSGY cable
 

The cable passes the circuit integrity test of BS 6387-2013, the fire resistance performance has reached the requirement of rigid MI cable. The advantage of MI cable over normal fire-retardant cable and fire-resistance:
(1) Guarantee the normal operation of power supply and communication system within 3 hours after fire occurrence, make the smoke toxicity (ZA1) emission within controllable scope, reduce greatly the secondary harm to human and is the highest fire resistant standard cable.
(2) Mineral insulated cable is nontoxic, smokeless and noncombustible, unable to cause to short circuit itself due to the fire disaster,  able to supply power for 180 minutes at 950℃ and endure water spraying and heavy impact during the fire.
Normal fire resistant cable is able to supply power for 90 minutes at 750℃, cannot endure water spraying and heavy impact; metal pipe and sealed bridge should be provided to realize the functions of water spraying and heavy impact endurance. Metal pipe and sealed bridge should be painted by fireproof materials 2-3 times per year.

Comparison between YYSY, YTSLY, YTSGY Flexible Mineral Insulated Cable and BTT Rigid Mineral Insulated Cable

Electrical performance
(1) Strong overload capacity : the filling material is inorganic high temperature resistant material, the short circuit overload capacity is higher than normal XLPE insulated cable
(2) Rated current: 25-1800A for single core cable , 16-500A for multi core cable
(3) Insulation resistance:  ≥1000MΩ.km, higher during fire
(4) Power frequency  withstand voltage: 5 min at 3500V phase to phase voltage without breakdown
 
Smoke toxicity:
Low smoke performance is tested through light transmittance according to bundled combustion method in GB/T 17651, the light transmittance can reach 60% or above. The halogen content is evaluated though ph value and conductivity in IEC 60754-2,  PH value≥4.3， conductivity≤10μs/m, the smoke toxicity during cable combustion is ZA1 class.