Installation, Operation & Maintenance Instructions 1530°C Chamber Furnaces CDF 15/1b 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 9.0 page Symbols & Warnings Installation Operation Maintenance Repairs & Replacements Fault Analysis Circuit Diagrams Fuses & Power Settings Specifications 2 2 4 7 9 13 14 15 16 MF56 – 1.
CDF 1.0 SYMBOLS & WARNINGS 1.1 Switches and Lights Instrument switch: when the instrument switch is operated the temperature control circuit is energised. Heat Light: the adjacent light glows or flashes to indicate that power is being supplied to the elements 1.2 Warning Symbols DANGER of electrical shock– read any warning printed by this symbol. DANGER – hot surface. Read any warning printed by this symbol. WARNING: all surfaces of a furnace may be hot.
CDF If the chimney is supplied unfitted, then fit it into the hole in the top of the furnace case. If the furnace is to be used to heat substances which emit fumes, then a fume extraction duct of about 150mm inlet diameter may be placed directly above the chimney outlet. Do not make a sealed connection to the furnace chimney as this causes excessive airflow through the chamber and results in poor temperature uniformity. 2.
CDF Technical Notes The furnaces covered by this manual have electronically controlled power limits. Do not attempt to calculate the Amps from the Wattage. High break capacity fuses should be used. Avoid fast-blow fuses and magnetic trip circuit breakers - consult Carbolite if in doubt. 3.0 OPERATION 3.1 Operating Cycle The furnace is fitted with an Instrument switch. The switch cuts off power to the control circuit. Connect the furnace to the electrical supply.
CDF the electric potential inside the chamber can be at any value between zero and the supply voltage. Unearthed probes can cause serious electric shock. 3.4 Atmospheres Chamber furnaces are not gas tight, so it should be understood that gas usage may be high, and that the chamber is likely always to contain some air. Residual oxygen levels of 1% are to be expected. In practice inert or oxidising gases may be used, but not combustible or toxic gases. MF56 – 1.
CDF 3.5 Operator Safety The furnace incorporates a safety switch which interrupts the heating element circuit when the door is opened. This prevents the user touching a live heating element, but also prevents the furnace from heating up if the door is left open. The operation of this switch should be checked periodically – see section 4.1.2. Avoid burns: furnace surfaces can be hot. Before you remove a hot object from the furnace make sure you have a safe place to put it down. 6 MF56 – 1.
CDF 4.0 MAINTENANCE 4.1 General Maintenance Preventive rather than reactive maintenance is to be preferred. The type and frequency depends on furnace use: the following are recommended. 4.1.1 Cleaning Soot deposits may form inside the furnace, depending on the process. At appropriate intervals remove these by heating as indicated in section 3.2. The furnace outer surface may be cleaned with a damp cloth. Do not allow water to enter the interior of the case or chamber. Do not clean with organic solvents.
CDF 4.5 Element Ageing Silicon carbide elements gradually increase in resistance with use: a process known as ageing. Their heating power reduces correspondingly. If the furnace does not reach temperature, or is slow, the elements have aged to a high a resistance and it may be necessary to replace them. 4.6 Power Adjustment The furnace control system incorporates electronic power limiting. Power is supplied to the elements in bursts of about 1/3rd second duration.
CDF 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 Note - 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.
CDF 5.5 Fuse Replacement Fuses are marked on the circuit diagram (section 7.0) with type codes, e.g. F1, F2. A list of the correct fuses is given in section 8.1. If any fuse has failed, it is advisable for an electrician to check the internal circuits. Replace any failed fuses with the correct type. For safety reasons do not fit larger capacity fuses without first consulting Carbolite. The fuses are near the cable entry point, and access is by removal of the back panel. 5.
CDF Gently insert the element into the location hole until it reaches the approximate depth of the front face insulation. (See photo 2) This should require no force at all. Then with a slight twisting action locate the front end of the element in the front face location hole and gently insert element as far as possible.(See photo’s 3 & 4) Again no force is required. There should be approximately 6-8 mm between the elements porcelain terminal connector and the rear insulation.
CDF New furnace: the diagrams indicate the connections. If you have any problems with this procedure, please contact our service division. A common feature of CDF models is that elements are in series between 200-240 volts. Replacements: make a note of the actual braid and cable connections to the elements. Using the reverse method described above, disconnect the braids or cables and carefully withdraw each element.
CDF 6.0 FAULT ANALYSIS A. Furnace Does Not Heat Up 1. The HEAT light The heating element has failed is ON 2.
CDF 7.0 CIRCUIT DIAGRAMS In all CDF models the safety switch in the diagram is a positive-break door switch. EMC Filters (if fitted): dependent on the model there may be one filter, or more than one fitted in parallel. The circuit diagram example does not show multiple filter arrangements. 7.1 Single Phase F1 N F1 L BU Contactor Filter if fitted R F2 PE F2 GR/Y Instrument Switch R Safety Switch BU Coil Heat TC Control thermocouple P SSR Element(s) G 14 MF56 – 1.
CDF 8.0 FUSES & POWER SETTINGS 8.1 Fuses F1-F3: Refer to the circuit diagrams. F1 Internal supply fuses Fitted if supply cable fitted. Fitted on-board to some types of EMC filter. 16 Amps: 38mm x 10mm type F F2 Auxiliary circuit fuses Fitted on-board to some types of EMC filter. May be omitted up to 10 Amp/phase supply rating. 2 Amps glass type F On board: 32mm x 6mm Customer fuses Recommended if cable fitted. See rating label for amperage; see table below for fuse rating.
9.0 SPECIFICATIONS Carbolite reserves the right to change specifications without notice. 9.1 Models Covered by this Manual MODEL Max. Temp. Max. Power Chamber Size (mm) (°C) (kW) H W Chamber Furnaces heated by Silicon Carbide elements. CDF 15/1b 1530°C 2.0 80 90 9.2 Approx. Capacity Net Weight D (l) (kg) 150 1.
