Mold-Masters Hot Runner, User Manual, Page: 94 / 319

6.3.9 Ungrounded Thermocouple Continuity Test
With an ungrounded thermocouple, there is no circuit or Ohms reading to
ground, unless the thermocouple is damaged or pinched. This allows for an
Ohms resistance (non-voltage) check prior to and after installation. To do this
test, do these steps:
1. Set up a multimeter to read Ohms resistance.
2. Connect one lead to the red thermocouple wire.
3. Connect the other lead to the mold plate that the hot runner system is
installed in.
4. If you see an Ohms resistance, replace the thermocouple (faulty
thermocouple).
5. Repeat steps 2–4 for the white thermocouple wire.
Do this test on all thermocouples.
6.4 Thermocouple Wiring Guidelines
CAUTION
Exceeding controller zone amperage will cause controller fuses to blow.
CAUTION
• Thermocouples are Type “J” ungrounded and color coded to ASA
standards. (White “+”/Red “- “).
• The tip must not be truncated or squeezed and must touch the bottom of
the bore in order to measure the correct temperature.
• Each heat source should have its own closed loop temperature control in
order to achieve accurate control.
• If there are not enough control zones, heat sources that have the same
wattage and affect the same environment, may be grouped together.
6.5 Functional Test with a Temperature
Controller
CAUTION
Never start the heating with more than 40% of power.
CAUTION
The functions of the electrical equipment must be checked. This test is
carried out with an appropriate temperature control device.
• Monitor the initial heating of the system to minimize risk.
• Stay a minimum of 5 minutes at 100°C (212°F) before increasing heat.
6.6 Re-testing
Where a portion of the electrical equipment is changed or modified, that
portion must be reverified and retested, as appropriate.
6-5 ELECTRICAL TESTING
Hot Runner User Manual
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