Carbolite ELF Series - Manual (Page 4)

ELF (B)
4
MF01 3.31
Amps: the actual supply must be capable of supplying the required amps. It should be fused at the
next available fuse size equal to or greater than the amps on the rating label.
A supply cable is fitted to 200-240V models, but may not be to 110-120V models. If there is no
cable, remove the back panel and connect a suitably rated cable to the internal terminals.
Either wire the supply cable directly to an isolator or fit it with a line plug. The plug or isolator
should be within easy reach of the operator to permit quick disconnection of the power.
For operator safety the supply MUST incorporate an earth (ground).
3.0 O PERATION
3.1 Operating Cycle
The furnace is fitted with an instrument switch. The switch cuts off power to the controller.
Connect the furnace to the electrical supply.
Operate the instrument switch to activate the temperature controller. The controller becomes
illuminated and goes through a short test cycle.
Close the furnace door and adjust the temperature controller – see controller manual
As the furnace heats up the Heat light glows steadily at first and then flashes as the furnace
approaches the desired temperature. For further information on temperature control, see controller
manual.
To turn the furnace off, set the Instrument switch to it’s off position; the controller display will go
blank. If the furnace is to be left off unattended, isolate it the electrical supply.
3.2 General Operating Notes
Heating element life is shortened by use at temperatures close to maximum. Do not leave the
furnace at high temperature when not required. The maximum temperature for ELF models is
1100°C (2012°F).
When heating large objects, in particular poor conductors, avoid shielding the thermocouple from
the heating elements. The thermocouple is intended to sense the temperature near the heating
element, but if a large cold object is placed in the chamber it may record the average temperature
of the object and the element, which can lead to overheating of the element. Allow large objects to
gain heat at a lower temperature and then adjust the controller setpoint to a temperature close to
the desired maximum.
Materials such as case hardening compounds and other reactive salts may attack the wire elements,
causing premature failure. The insulation chamber includes a ceramic hearth that helps to protect
the insulated floor.
Note that if the door vents are open then the entry of cold air through the vents can give rise to a
cool area in the chamber.
The moulded light weight ceramic fibre insulation can easily be marked by accidental contact with
tongs etc. Some fine cracks may be visible at the front of the insulation, or may develop in the
surface of the chamber due to the progressive shrinkage of the ceramic fibres. Cracks are not
usually detrimental to the functioning of the furnace.
When heating materials that produce smoke or fumes, the chimney must be correctly fitted and
unobstructed. Otherwise, soot may accumulate in the chamber and could possibly cause an
electrical breakdown of the heating element. To prevent this, regularly heat the furnace up to
maximum temperature for one hour without load to burn away the soot.