BLF
R
EPAIRS
& R
EPLACEMENTS
5.1 Safety Warning – Disconnection from Supply
Always ensure that the furnace is disconnected from the supply before repair work
is carried out.
5.2
Safety Warning - Refractory Fibrous Insulation
This furnace contains refractory fibres in its thermal insulation. These materials
may be in the form of fibre blanket or felt, vacuum formed board or shapes,
mineral wool slab or loose fill fibre.
Normal use of the furnace does not result in any significant level of airborne dust
from these materials, but much higher levels may be encountered during maintenance or repair.
Whilst there is no evidence of any long term health hazards, we strongly recommend that safety
precautions are taken whenever the materials are handled.
Exposure to dust from fibre which has been used at high temperatures may cause
respiratory disease.
When handling fibre always use an approved mask, eye protection, gloves and long
sleeved clothing.
Avoid breaking up waste material. Dispose of waste fibre in sealed containers.
After handling rinse exposed skin with water before washing gently with soap (not
detergent). Wash work clothing separately.
Before commencing any major repairs we recommend reference to the European Ceramic Fibre
Industry Association Bulletin No. 11 and the UK Health and Safety Executive Guidance Note
EH46.
We can provide further information on request. Alternatively our service division can quote for
any repairs to be carried out at your premises or ours.
5.3
Temperature Controller Replacement
2216, 2416, 2408 etc. Ease apart the two lugs at the side; grip the instrument and withdraw it from
its sleeve; push in the replacement.
5.4 Fuse Replacement
Access to internal fuses is by removal of the furnace cover near the cable entry point. See section
8.1 for details of fuses fitted.
5.5
Thermocouple Replacement
Disconnect the furnace from the supply, and remove the furnace cover or back panel.
Make a note of the thermocouple connections.
The negative leg of the thermocouple is marked
blue.
The “compensating” cable for 1700° and 1800°C thermocouples is plain copper.
Disconnect the thermocouple from its terminal block.
Bend the metal tag, or release the screw, to release the thermocouple sheath; withdraw the sheath,
and shake out any fragments of thermocouple.
Re-assemble with a new thermocouple observing the colour coding, ensuring that the
thermocouple is not twisted as it is being inserted and that the metal tag is bent back, or the screw
inserted, to grip the sheath.
10
MF23
