Installation, Operation & Maintenance Instructions 1200°C - 1300°C Chamber Furnaces GPC models 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.
GPC 1.0 INTRODUCTION 1.1 GPC models This manual covers both the “laboratory” and “industrial” GPC furnaces. The laboratory models are GPC 12/36, GPC 13/36, GPC 12/65 and GPC 13/65. These are designed for bench mounting, but can be supplied with a stand. The industrial models are GPC 12/131, 13/131 and GPC 12/200. These are floor standing units. The furnaces are fundamentally similar in operation, but the industrial sizes are altogether larger and therefore require somewhat different handling and siting.
GPC 2.0 INSTALLATION 2.1 Unpacking & Handling Laboratory Models. When unpacking or moving the furnace always lift it by its base. Never lift it by the door. Use two people to carry the furnace. Remove any packing material from the door gear and furnace chamber before use. Industrial Models. Use a fork lift or pallet truck to position the furnace on a level floor.
GPC 2.5 Electrical Connections Connection by a qualified electrician is recommended. All GPC models have three internal circuits and are normally supplied for three phase supply. This may be either star or delta, but a furnace must only be connected to the type and voltage of supply for which it was made (but see 2.6). If the furnace is ordered for a single phase supply, this may be Live to Neutral reversible or non-reversible, or Live to Live.
GPC 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. Connect the furnace to the electrical supply. Operate the instrument switch to activate the temperature controller.
GPC 3.4 Atmospheres When an optional gas inlet is fitted there is a label near the inlet saying "INERT GAS ONLY". In practice inert or oxidising gases may be used, but not combustible or toxic gases. 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 1% are to be expected. If a metal retort is supplied with this furnace, please see the supplementary manual MS05. 3.
GPC 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.
GPC 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.
GPC 5.5 Thermocouple Replacement Disconnect the furnace from the supply, and remove the furnace back panel. Make a note of the thermocouple connections. The negative leg of the thermocouple is marked blue. Compensating cable colour codings are: negative positive (type R) white orange Disconnect the thermocouple from its terminal block. Remove the screw to release the thermocouple sheath, withdraw the sheath, and shake out any fragments of thermocouple.
GPC Disconnect the furnace from the electrical supply and remove the back panel. It is advisable to make a written plan showing all the element and thermocouple connections to avoid any problems when reconnecting to the power and other wires. Loosen the clamping screws onto the terminal blocks holding the faulty element. Use two spanners to avoid cracking the porcelain material. If necessary straighten the bent ends of the wire. This must be done for both ends of the element, i.e.
GPC 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.
GPC 7.0 CIRCUIT DIAGRAMS In all GPC 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 examples do not show multiple filter arrangements. ISOLATOR: the industrial models have an internal isolator which is not shown in these diagrams. 7.1 Single Phase for GPC -/36 see 7.6 and section 2.
GPC 7.3 3-phase without neutral (delta) for GPC -/36 see 7.6 and section 2.6 Filter (if fitted) L3 L2 L1 F1 contactor F2 PE F3 Instrument Switch heat on coil Safety switch overtemp. controller temperature controller if fitted thermocouple e l e m e n t (s) F3 e l e m e n t (s) heat on F3 e l e m e n t (s) heat on F3 SSR F3 SSR thermocouple F3 SSR 3-phase without neutral (star – e.g. 380 to 415V) 7.
GPC 3-phase “universal” wiring 7.6 applicable to GPC -/36 - see section 2.6 Filters (if fitted) N L N L N L F1 F2 F3 Contactors (2 or 3) Instrument Switch coil safety switch overtemp. controller temperature controller heat on coil if fitted thermocouple e l e m e n t (s) F3 e l e m e n t (s) heat on F3 heat on e l e m e n t (s) F3 SSR F3 SSR thermocouple F3 SSR Fuses F1 are always present in this wiring design.
GPC 8.0 FUSES & POWER SETTINGS 8.1 8.2 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. F2 Auxiliary circuit fuses Fitted on board to some types of EMC filter. May be omitted up to 25Amp/phase supply rating. F3 Heat Light fuses May be omitted up to 25 Amp/phase supply rating. Customer fuses Required if no supply cable fitted. Recommended if cable fitted.
9.0 SPECIFICATIONS Carbolite reserves the right to change specifications without notice. 9.1 Models Covered by this Manual MODEL Max. Max. Chamber Size (mm) Approx. Temp. Power Capacity (°C) (kW) H W D (l) Chamber furnaces heated by resistance wire resting on refractory formers.
