Installation, Operation & Maintenance Instructions 1000°C - 1200°C Tube furnaces types MTF, CTF This manual is for the guidance of operators of the above Carbolite products and should be read before the furnace is connected to the electricity supply. CONTENTS Section 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.
MTF, CTF 1.0 INTRODUCTION 1.1 Switches and Lights Instrument switch: when the instrument switch is operated the temperature control circuit is energised. Heat Switch: the switch disconnects power to the heating elements; unless this switch is off there is a danger of electric shock when inserting objects into the furnace Heat Light: the adjacent light glows or flashes to indicate that power is being supplied to the elements 1.
MTF, CTF 2.0 INSTALLATION 2.1 Unpacking & Handling When unpacking or moving the furnace always lift it by its base or by both ends of the main body. Never lift it by its work tube or the surrounding insulation. For the larger models, or where the furnace and control box are not fixed together, use two people to carry the furnace. Remove any packing material from inside the furnace before use.
MTF, CTF 2.4 Electrical Connections Connection by a qualified electrician is recommended. All furnaces covered by this manual may be ordered for single phase A.C. supply, which may be Live to Neutral non-reversible, Live to Neutral reversible or Live to Live. Some models can be supplied for three phase use; some for use on two phases of a three phase with neutral supply (one phase unused). Check the furnace rating label before connection.
MTF, CTF 3.0 OPERATION The instructions for operating the temperature controller are given in a separate manual. If the furnace is fitted with a time switch, see also the supplementary manual MS03. If cascade control is fitted, see the supplementary manual MS07. 3.1 Operating Cycle The furnace is fitted with an instrument switch. The switch cuts off power to the control circuit. There is also a heater switch which can be used to disconnect power to the elements.
MTF, CTF 3.4 Tube Life A ceramic work tube may be cracked if workpieces are inserted too quickly or at temperatures below 900°C (when the tube is more brittle). Large pieces should also be heated slowly to ensure that large temperature differences do not arise. Poor thermal contact should be encouraged between the workpiece and the tube; crucibles or boats should be of low thermal mass and should have feet to reduce the contact with the tube (fig. 4). Do not set too high a heating rate.
MTF, CTF 4.0 MAINTENANCE 4.1 General Maintenance No routine maintenance is required. The outer surfaces may be cleaned with a damp cloth. Do not allow water to enter the interior of the case, tube or control box. Do not clean with organic solvents. 4.2 Calibration After prolonged use the controller and/or thermocouple could require recalibration. This would be important for processes which require accurate temperature readings or which use the furnace close to its maximum temperature.
MTF, CTF 5.0 REPAIRS & REPLACEMENTS 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 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.
MTF, CTF 5.5 Thermocouple Replacement The coverings and guards which must be removed to gain access to the thermocouple depend on the model, its orientation (horizontal or vertical), and possibly other options and fittings. It will usually be necessary to separate the furnace from its base or stand. On horizontal CTF models one outer end-cap will need to be removed, and on MTF and vertical CTF models the terminal cover.
MTF, CTF Check the cylindrical case and clean out as appropriate. Remove any insulation sleeving from the tails of the old element and fit to the replacement element. Slide in the new element(s). Close up the furnace again, refitting the terminal strip (where applicable) and the end-caps. Any cut made in the insulation should close up completely: if the insulation appears loose or damaged in any way, please contact our service division. Reverse the rest of the disassembly process.
MTF, CTF 6.0 FAULT ANALYSIS A. Furnace Does Not Heat Up 1. The HEAT light The heating element has failed is ON 2. The HEAT light is OFF Check also that the SSR is working correctly The controller shows a very high temperature or a code such as S.
MTF, CTF 7.0 CIRCUIT DIAGRAMS Safety Switches type A: a 2-pole Heater Switch is fitted directly in the element circuit in models up to 16A rating. Safety Switch type B: a Heater Switch is fitted into the contactor coil circuit in models over 16A. 7.1 Single Phase N L PE F1 Filter (if fitted) F3 contactor if fitted F2 safety switches A Instrument Switch safety switch B heat on coil if fitted overtemp. controller thermocouple e l e m e n t (s) F3 SSR temperature controller thermocouple 7.
MTF, CTF 7.4 3-phase without neutral (delta) Filter (if fitted) L3 L2 L1 F1 contactor F2 PE F3 Instrument Switch heat on coil safety switch overtemp. controller if fitted e l e m e n t (s) F3 F3 e l e m e n t (s) heat on e l e m e n t (s) heat on F3 thermocouple SSR F3 temperature SSR controller F3 thermocouple 7.5 SSR 3-phase without neutral (star – e.g.
MTF, CTF 14 MF03 3.
MTF, CTF 8.0 FUSES & POWER SETTINGS 8.1 F1 F2 F3 Fuses Internal supply fuses Auxiliary circuit fuses Heat Light fuses Customer fuses F1-F3: Refer to the circuit diagrams. Fitted if supply cable fitted. Fitted on board to some types of EMC filter. Fitted on board to some types of EMC filter. May be omitted up to 10 Amp/phase supply rating. May be omitted up to 25 Amp/phase supply rating. Required if no supply cable fitted. Recommended if cable fitted.
9.0 SPECIFICATIONS 9.1 Carbolite reserves the right to change specifications without notice. Models Covered by this Manual MODEL Work Work Heated Uniform Net Tube Tube Length Zone 1 Weight2 Bore Length Length (°C) (kW) (mm) (mm) (mm) (mm) (kg) Tube furnaces with a ceramic work tube wound with resistance wire MTF 10/15/130 1000°C 0.4 15 150 130 30 3 MTF 10/25/130 1000°C 0.4 25 150 130 40 3 MTF 12/25/250 1200°C 0.7 25 300 250 80 10 MTF 12/25/400 1200°C 1.0 25 450 400 130 15 MTF 12/38/250 1200°C 1.
