There are several fire test standards for communication cables: UL1666, UL910, IEC332-1 and IEC332-3.IEC754, IEC1034
A) IEC332-1 and IEC332-3 flame retardant grades
In order to evaluate the flame retardant performance of cables, the INTERNATIONAL Electrotechnical Commission has formulated three standards: IEC332-1, IEC332-2 and IEC332-3.
Iec332-1 and IEC332-2 were used to assess the flame retardation of a single cable laid at tilt and vertical, respectively, while IEC332-3 was used to assess the vertical combustion of bundles, which is much higher than the flame retardation requirement for bundles.
B) UL flame retardant rating
These details will be printed on any cable listed in the UL that has been tested and meets a certain fire rating.
Generally, the cable will be stamped with the fire rating, approval reference number, and UL identifier (UL flag or UL in parentheses).
Supercharged stage -CMP stage
This cable is the most required in UL fire protection standards and complies with UL910 standard. When a fan is used to force the cable towards the flame, the cable will extinguish within 5 meters of the flame spread.
And the cable will not emit toxic smoke or steam during combustion or extreme heat.
Such cables are usually installed in ventilation ducts or air handling equipment used by the air reflux booster system.
UL910 is used for testing flame propagation and smoke concentration of space-borne cables and optical cables in the air environment, for use in Canada, Japan, Mexico and the United States.
The FLAME retardant property of THE FEP material conforming to the UL910 standard is better than that of the LSZH material conforming to the IEC332-1 and IEC332-3 standard, and the smoke concentration in the combustion is low.
If it does not burn, it can reduce the spread of fire, and even if it does burn, it can minimize the loss of fire and harm to human beings.
Cables approved by IEC332-1 and IEC332-3 can be used for vertical channels, and CMP cables verified by UL910 can be used for horizontal cables.
The UL910 is standard high, 300,000 BTU burners cannot spread more than 5 feet and cannot be blown for 20 minutes at a temperature of around 850 ° C.
LSZH material conforming to THE IEC332-3 and 332-1 standards burns at a low combustion point of about 80℃, and the smoke concentration during combustion is higher than FEP.
Fire resistant cables that pass this test are considered to be fire retardant grade cables suitable for pressure-ventilated Spaces.
Trunk class -CMR class
This is the second rated cable, which is rated UL1666. Under forced fan blowing, the bundle must extinguish within five metres of the flames, as is often the case in mainline fires.
But there is no smoke or toxicity code for main-class cables.
These fire grade cables are commonly used in building mains and horizontal cables.
Commercial grade -CM grade
The cables must extinguish themselves within 5 meters of the flame spread, but there are no restrictions on fan forced blowing.
There are no smoke or toxicity regulations.
Often used in horizontal lines.
Universal grade -CMG grade
Similar to commercial grade.
Home grade -CMX grade
Minimum UL fire rating for communication wiring, a cable must extinguish itself within 5 m of flame spread.
There is also no smoke and toxicity code for this class and it is only used in home or small office systems where each cable is laid separately.
Such cables shall not be laid in bundles.
C) IEC754 and IEC1034 halogen-free and low smoke grade
In order to evaluate the flame retardant, smoke or toxic performance of cables, the International Electrotechnical Commission has formulated IEC754-1, IEC754-2, IEC1034 and other standards.
D) IEC331 Fire rating
In order to evaluate the fire performance of cables, the British Electrotechnical Commission and the International Electrotechnical Commission respectively formulated BS6387 and IEC331, which are used to maintain the circuit integrity under fire conditions.