Carbolite VST 17/-- - Manual (Page 9)

1700° Tube
LMF32C – 1.07 9
4.0 R EPAIRS & R EPLACEMENTS
4.1 Safety Warning – Disconnection from Supply
Always ensure that the furnace is disconnected from the supply before repair work
is carried out.
4.2 Safety Warning - Refractory Fibrous Insulation
Insulation made from High Temperature Insulation Wool
Refractory Ceramic Fibre, (better described as Alumino Silicate Wool) (ASW)
This product contains alumino silicate wool products in its thermal insulation. These materials
may be in the form of blanket or felt, formed board or shapes, mineral wool slab or loose fill wool.
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 fibrous dust may cause respiratory disease.
When handling the material always use an approved respiratory protection equipment
(RPE-i.e. FFP3), eye protection, gloves and long sleeved clothing.
Avoid breaking up waste material. Dispose of waste 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 Association
representing the High Temperature Insulation Wool industry (www.ecfia.eu)
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.
4.3 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.
4.4 Fuse Replacement
Access to internal fuses is by removal of the furnace or control box cover or back panel. See
section 7.1 for details of fuses fitted.
4.5 Thermocouple Replacement
Disconnect the furnace from the supply, and remove the top cover.
Make a note of the thermocouple connections. The negative leg of the thermocouple is marked
blue. The “compensating” cable for 1700 & 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.
4.6 Insulation Replacement
After any replacement of insulation material, run the furnace at 1500°C to burn off volatile matter.
Do this is a well ventilated area, without the work tube in place.