6. Load station tuning.
WARNING:
Make sure that the
circuit breaker is turned off before
adjusting heat station components.
This section describes the procedures for tuning the heat station so that full power will be
obtained at the desired frequency.
6.1. Tuning.
This section provides the procedures required for the final tuning of the heat station for a
specific heating coil and load. It is assumed that the initial setup of the heat station has been
completed as described in section 3.
The aim of this exercise is to have the unit operating at full power of 3kW without any
indicators lit.
1. Ensure that the heat switch on the front panel is in the OFF position, that the MODE
selection switch is in the MAN (manual) position and that the power level knob is turned
fully counter-clockwise (see Figure 2 on page 9). Turn on the circuit breaker. The green
STANDBY indicator should light up, indicating that the unit is powered up. Press the reset
button if any red trip indicators are lit.
2. Put the HEAT switch in the ON position.
•
If the unit is not delivering full power and the frequency is indicated as ~135kHz (no limit
indicators will be lit), the tank frequency is outside the range of the unit.
•
If the current limit indicator lights up or a current trip occurs, continue increasing the
inductance of the series inductor, i.e. increase the turns of the inductor, until the current
limit indicator stops to light up at full power. Increase the turns using the turn selector
bar, as described in section 6.2.1 on page 16. .
•
If the frequency limit indicator lights up or a frequency trip occurs, continue decreasing
the inductance of the series inductor, i.e. decrease the turns of the inductor, until the
frequency limit indicator stops to light up at full power. Decrease the turns in small
increments by using the shorting bar, as described in 6.2.1 on page 16.
3. Increasing the series inductance until the current reading is around 50% at full power will
optimize the efficiency of the system. This will act to protect the transformer and capacitors
from overheating. Highly recommended!
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