Parallel Circuit – Constant Watt for Frost Protection

Parallel circuit heating tape is designed to be cut from reel lengths and site terminated to suit pipe work. The heating tape consists of a number of short heating zones, up to 1m long, each connected across a pair of continuous bus-wire conductors.

Each complete heating zone will give its full rated design output, 10, 15, 20 or 30 W/m, with circuit voltage applied to the bus-wire conductors. Normal rated voltage is 110v or 230v AC.


The heating tape has a core comprising two bus-wire conductors contained within an extruded silicone rubber sheath. This sheath is notched on alternate sides, at predetermined intervals, to expose a short section of bus-wire conductor.

Nichrome resistance wire is wound, at regular spacing, around the core as a continuous conductor, making contact with the bus-wires at the exposed points.

After completion of heater conductor winding a high temperature soldered joint is made at each contact point ensuring that a number of conductor strands are securely bonded to the bus-wires.

An extruded outer sheath is then placed over the core and heater element to complete the heater tape assembly. The whole tape has a tinned copper metallic braid to comply with the requirements of BSEN 62395.

For certain applications the heating tape may have a stainless steel braided outer cover.