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PH250T Family

The industrial frequency induction preheater is an apparatus designed to preheat copper, aluminum, thermocouples or similar wires on extrusion lines, before the wire comes into contact with the hot insulating material.
The bare wire passes inside the equipment through two or more return pulleys. Through the contact on the conductive upper pulley the wire forms a short circuit in a special transformer. The electronic regulation and control system of the current allows to heat the wire up to the desired temperature.

It’s suggested to:

  • DELETE THERMAL SHOCKS caused by the contraction of the hot insulation material on the cold wire
  • INCREASE THE EXTRUSION SPEED especially with those special insulating materials (ex: cross-linked polyethylene, fluorinated)
  • IMPROVE THE CABLE PEELING FEATURES of electrical wiring wires
  • IMPROVE THE CABLES’ PHYSICAL AND MECHANICAL FEATURES avoiding defects like the cracking of the insulation
SIF has developed over the years a complete range of preheaters, which is unrivaled on the market, with the possibility to customize solutions according to the customer's needs, depending on the application and the wire range to preheat.
 Small wire series
Power (kVA)8121520
Output Voltage (V)8 – 12 – 16 – 20
Pulleys diameter (mm)180 – 230
Supply Voltage (V)400
Line Speed (m/min)from 10 to 2500*

* specify during request process

 Big wire series
Power (kVA)20253040
Output Voltage (V)8 – 12 – 16 – 20
Pulleys diameter (mm)310 – 400 – 500 - 600
Supply Voltage (V)400
Line Speed (m/min)from 10 to 2500*

* specify during request process


Easy and independent setting of preheating recipes for each type of wire without SIF intervention, with memorization and coding with numerical code

Offset for automatic adjustment of preheat curves according to the starting wire temperature

Unique preheater on the market suitable for working at both high and low speeds

Control Unit Features: 
The added value to the product is surely given by the innovative PH250T50R control system studied by SIF, which guarantees simplicity of installation and use, with the following characteristics:
  • Smart and flexible system of regulation by PLC that allows to adapt the equipment for future needs of new types of wire heating without SIF intervention
  • Colour Touch screen to display the functions.
  • Simple creation of heating curves for the different types of wire, associating the current value with the line speed to reach the desired temperature. In this way it is possible to maintain the constant temperature within a tolerance as the speed varies and during both the rising and falling ramps of the line.
  • Possibility to memorize 50 recipes using a numerical code, through a simple operator interface. Each code can be associated with: a description, some useful data, 20 adjustment steps.
  • The curve setting is made only the first time a new type of wire is used. For the following times, it is enough to select the numerical code corresponding to the wire to be heated and the appliance will automatically adjust ccording to the speed of the line.
  • Manual offset, which allows to move the set curve, in case the wire is hotter or colder than the desired temperature. In fact, it may happen that the initial wire temperature is higher or lower than the initial temperature at which the wire was when the curve was created.
  • Preheating with both high and low line speeds.
  • PROFINET interface already included for remote control.
  • Visualization of the temperature measurement directly on the touch screen
  • Line direction configurable on the touch screen.

Hardware and preheater shell are characterized by:
  • Solid metallic structure and small overall dimensions.
  • Inspection glass.
  • The door and the micro of safety compliant with accident prevention standards.
  • Emergency button.
  • Metallic wheels for the movement.
  • Height of the passing of the wire on the line: 1015 mm ± 35mm
  • Direction of the line: from left to right or from right to left (to be requested when ordering).
  • Encoder for line speed measurement.
  • General switch to cut off power supply.
  • Siemens PLC and color graphic Touch Screen for system management
  • Driver for the regulation of the power preheating system current
  • Current and temperature measurement group

All the SIF’s Preheaters are:
  • delivered with instruction manuals and electric diagrams
  • compliant to the Council's mandatory product standards 2014/30/UE and 2014/35/UE of the European Parliament and of the Council of 26 February 2014

TM250 - Temperature verification system up to 250° C

This system is used to check the temperature of the wire before it enters the extruder. It is complementary to the preheater and is very useful to:

  • help the operator on the line to create the heating curve for the type of wire he wants to use
  • simplify the temperature verification operation in both the initial phase and eventually during production.

The real added value of the system, are the innovative solutions born from the inventiveness of the Research & Development team, which has been able to combine creativity and engineering, for:

    It is possible to use the system for a wide range of wire diameters.
    through an easy operation, the measure is performed.


System features:

  1. Special thermocouple for sliding contact
  2. Wire-guiding Ceramic pulleys
    In order for the thermocouple to touch the wire in the best way to detect the temperature
  3. Mechanical spring contact system
  4. Protection Carter
  5. Aluminum support
    For a simple fixing to the structure of the preheater
  6. Reading of temperature value directly on the touch screen

Other available options for the system:

  • Non-contact or higher temperature measurement systemsavailable on request
  • Digital temperature reading instrument
    Supplied with calibration report.
  • Aluminum support with wheels
    For an easy movement of the measurement system on different locations.


Over the years, SIF has also created very special models for specific customer requirements. We therefore invite you as always to contact us to help you choose the right model for your needs and to study any customized solutions.