Heating Elements 11
User Guide v 1.4 — September 2015 Hot Runner Temperature Control
In either control method, the Altanium controller recalculates the power output
requirements for the entire system every 8 milliseconds to obtain the maximum control
resolution. By combining either of the above control methods with the Active Reasoning
Technology (ART) control algorithm, it is possible to achieve accurate temperature control
with the expectation of control accuracy of ± 1 digit under steady state conditions.
2.3 Heating Elements
Hot runner molds can have a number of different types of heating elements:
• Integral, which is a part of the probe.
• Cartridge, which is slid into the probe or directly into the mold steel.
In the manifold, a series of cartridge heaters or bent tubular style heaters are normally used.
The wire inside an element is typically made of nickel-chrome, which is then surrounded by
magnesium oxide. The size of this wire and number of turns determine its resistance, which
in turn determines its wattage (the amount of energy). This determines its performance in
the mold. Undersize heating elements (too little wattage) create a serious problem when the
control asks for power and none is available. In almost all cases it is better to be oversize than
undersize in a hot runner mold.
If your heating element supplier has not provided you with wattage, resistance or amperage
information for your heaters, the Altanium controller will provide this for you. Alternatively,
you can determine this information using OHMS Law. The diagram and formulas below show
you how.
1. Disconnect all electrical power from the mold and the controller.
2. Using your multimeter, set the selector to measure resistance.
3. Place the (red) positive lead onto the first wire from the heating element and place the
(black) negative lead from the meter onto the second wire (these may be pins on a
connector, or the zone output fuses in the system as long as you are sure they are
connected to the heating element).
The meter will now display a resistance in ohms. Note this measurement on a piece of
paper.
WARNING!
Electrical hazard – risk of death or serious injury. Lock out and tag the Altanium main
controller switch, and then disconnect all electrical power from the mold and
controller prior to performing this test. Failure to lock and tag and disconnect the
power could result in serious injury or death.
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