Customized Products

IEC 60331 Indoor Fire Resistant Unarmoured Telephone Cable


This cable is used for the internal wiring of building when the circuit integrity during fire is paramount. The cable

is intended to take the place of LSZH sheathed cables and will withstand similar environments with a similar

working life. It is intended for use in fire fighting plants with mica tapes, with aluminium foil and LSZH outer


Fire Performance

﹡Fire Resistance: IEC 60331.

﹡Flame Retardance: IEC 60332-3C

﹡Corrossive and Acid Gas Emission Test: Hydrochloric acid yield less than 0.5% in accordance with IEC 60754-


﹡Smoke Density: Percentage of light transmitted is greater than 60% when tested in accordance with IEC



IEC 60331 Indoor Fire Resistant Unarmoured Telephone Cable

Conductor: Solid annealed bare copper sized 0.6mm.

Fire Barrier: Mica tape.

Insulation: Polyethylene (PE) or Low smoke fume zero halogen compound (LSZH).

Twisting: Two colored insulated conductors are uniformly twisted together to form a pair.

Shape: Circular

Screen: Overall Aluminium/Polyester tape

Drain Wire: Solid copper wire sized 0.6mm.

Outer Sheath: Flame retardant low smoke fume zero halogen compound (LSZH)

Sheath color: Black


The cable is marked with white or other colors as follows:

Caledonian Cables Co., Ltd

Type and size of cable

Manufacturing date

Meter Marking

The meter mark is printed every meter with an accuracy of 0.5%.

Other printing are available according to customer request.

Table 1. Dimensions

Diameter of Conductor (mm)

Insulation Thickness (mm)

Thickness of Outer Sheath (mm)

Diameter of Cable (mm)

Approx. Weight (kg/km)




24.0 ± 2.0