6.0 Maintenance
6.7
Element Ageing
Silicon carbide elements gradually increase in resistance with use; a process known as
ageing. Their heating power reduces correspondingly. To ensure sufficient power to the
product, it may be necessary to adjust the power limit and, ultimately, replace the
elements - taking care to readjust the power limit.
If the product does not reach temperature, or is slow, check the power limit setting and
increase the value by 5%. It is recommended to make a note of the new settings and
the date of the adjustment in section 10.0. Increase the power limit in steps of 5% until
the product regains its original performance.
If the power limit is set to 100% a new set of heating elements is required.
Please note: it is not possible to use the cold resistance of the element as a measure
of ageing as the cold resistance is not an accurate indicator of hot resistance. Hot
resistance is used to calculate furnace power.
See the controller instructions for how to adjust the controller. Always record the setting
when first making an adjustment. If new elements are fitted, return the adjustments to
the original value. A table of standard power limits is given in section 10.0.
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