>> This is a parallel resistance, cut to length on site self-regulating heating cable designed for frost protection, process pipework maintaining and hot water temperature maintaining.
The heating cable adjusts heat output to equal the heat loss from the pipe work. As pipe temperature falls under no-flow conditions or due to decreases in external or internal temperature, output
increases. As the pipe temperature increases under flow conditions or as a result of increasing external or internal temperature so output decreases.
The heating cable has a core comprising two bus-wire conductors contained within an extruded semi-conductive self-limiting heater core with an outer insulating polyolefin sheath.
The heating cable has an earth protection screen in the form of a foil jacket covering a multi strand earth lead.
The cable is finished with a further protective thermoplastic outer sheath over the earth screen.
FBTX heating cable is certified for use in hazardous areas.
|Conductors||Copper stranded flexible 1,23mm²|
|Withstand temp||80ºC Un-energised 65ºC Energised|
|Braid||Foil jacket with multi strand earth lead|
|Over sheath||Thermo-plastic elastomer|
|Weight||6kg/100m un-braided 7,8kg/100m braided|
|Type||Volts||Watt/m at 10°C||Max circuit length (m)|
|16A CB||25A CB|
To calculate heat loss per meter of pipe:
Heat losses W/m = Δt x ke x Loss Factor
Δt = Pipe temp. – Ambient temp
ke = Thermal conductivity
|Pipe NB (mm)||Thermal insulation thickness (mm)|
|Loss Factor (From BS 6351)|
To comply with BS 6351 allowance should be taken of maximum heater resistance tolerance (± 10%) and voltage variation (± 6%) = 1.1/(0.94)² = 1.25 x Heat Loss.
A further design factor of 10% may be added.