Carbolite HTF 18 - Manual (Page 9)

MF47-3.05 9
It is advisable also to obtain element clamps and insulators (not included in kit). Individual spares
are also available.
When ordering spares please quote the model details as requested above.
4.5 Power Adjustment (Controller)
The furnace controller incorporates a power limit parameter OP.Hi which is usually inaccessible to
the operator.
Occasionally the power limit is set to zero to permit demonstration of the controls without the
heating elements taking power. In this case the power limit is accessible to the operator and may be
reset to its standard value of 100.
4.6 Power Adjustment (Thyristor)
The current-limiting thyristor stacks which control power to the elements are fitted with an
adjustable resistor which is factory set to limit the maximum current supplied. In the event of a
change of supply voltage, or the fitting of a new thyristor, re-adjustment is required. See section
5.4.
4.7 Low Voltage Compensation
If the supply voltage proves to be routinely below the nominal figure for which the furnace has
been set up, there is a “+2%” position on the transformer primary side which may be used instead
of the standard position. See section 5.10.