Contents This manual is for guidance on the use of the Carbolite Gero product specified on the front cover. This manual should be read thoroughly before unpacking and using the furnace or oven. The model details and serial number are shown on the back of this manual.
Page 3
3.8.7 To pause (hold) a program 3.8.8 To stop and reset a program 3.8.9 To run a different program (P10 and P25) 3.8.10 Program Status 3.8.11 Program Hold with Holdback 3.8.12 Power Failure Recovery 3.8.13 Alarms 3.8.14 Program Example 1 3.8.15 Program Example 2 Controller Options...
Page 4
Navigation Diagram 6.0 Operation Operating Cycle Emergency Stop Button General Operating Advice Atmospheres & Corrosive Materials Operator Safety Notes on Temperature Control Insulation Cracking Thermocouple Warnings Inverted Crucible Option 6.10 Element Protection Tube Option 7.0 Maintenance General Maintenance Maintenance Schedule 7.2.1 Cleaning Calibration...
Page 5
11.0 Fuses and Power Settings 11.1 Fuses 11.2 Power Settings 12.0 Specifications 12.1 Environment...
1.0 Symbols and Warnings 1.0 Symbols and Warnings 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. General Warnings DANGER –...
2.0 Installation 2.0 Installation Unpacking and Handling When unpacking or moving the product always lift it by its base. Do not use the door or any other protruding parts. The product contains a transformer and is heavy: use two or more people to carry the product. Some models may alternatively be lifted by fitting lifting bolts to captive threads in the top of the case.
Page 8
2.0 Installation Depending on the application of the product, it may be appropriate to position it under an extraction hood. Ensure the extraction hood is switched on during use. Ensure that the product is placed in such a way that it can be quickly switched off or disconnected from the electrical supply.
2.0 Installation Tie Wrap Removal Instructions The motor powered arm that operates the hearth movement has been fixed in place for transit. Please ensure the plastic tie wrap used to fix the arm is removed before operation. 1. Remove the back panel of the furnace. 2.
2.0 Installation 2.4 Fitting the Chimney and Heating Elements Please refer to the Element Installation and Replacement in section 8.0. Wear eye protection when handling the heating elements. The molybdenum disilicide elements are EXCEPTIONALLY FRAGILE and are packed separately, together with other items shown in the list. separately packed items Elements Element Clamps...
2.0 Installation Transit Clamps – dependent on model: the example shown here is for the 3 litre models; remove any transit clamps as shown. Fit the ceramic chimney to the hole that exits the top of the chamber. Most models are supplied with an insulation piece to fit around the chimney;...
Page 12
2.0 Installation Electrical Connection Details: Supply Types Supply Terminal Label Cable Colour Reversible or Live- Live - Neutral Live to either power conductor 1-phase L Brown to live (For USA 200-240V, connect L1) to the other power conductor Blue to neutral (For USA 200-240V, connect L2) to earth...
3.0 3508 Controller 3.0 3508 Controller PID control This controller uses PID (Proportional Integral Derivative) temperature control. This type of control uses a complex mathematical control system to adjust the heating power and achieve the desired temperature. 3508P1 The 3508P1 is a digital temperature controller which uses PID algorithm to give excellent temperature control when properly set.
3.0 3508 Controller Basic Operation Alarm Indicator Power Output Indicator Not Used Runs, Holds, Resets the current program Page Scroll Down Power Output Percentage Program Setpoint Temperature (PSP) when a program is running Setpoint Temperature (SP) when basic controlling...
3.0 3508 Controller Measurement Temperature Measurement Units 3.5.1 Controller Layout 3.5.2 Keys A/ Man Disabled Runs, Holds or Resets the current program. Hold down for 3 RUN/ HOLD seconds to Reset. Scrolls through the page headings. Hold down for 3 seconds Page Key to access further levels, pass codes are required.
3.0 3508 Controller The controller will immediately attempt to reach the set temperature and maintain it. This will cause the product to heat as quickly as possible which may not be appropriate where the product contains sensitive ceramic components. For products with ceramic components, e.g.
3.0 3508 Controller To Enter Level 2: 1. Press and hold page for 3 seconds. The display will show “Access Goto Level 1” 2. Press up to select level 2. After a short pause the display will show “Access Pass code”. 3.
3.0 3508 Controller 3.7.3 Units Press page until "Units" is displayed. Press up or down to select: Celsius Fahrenheit Kelvin 3.7.4 Language The text on the 3508 Controller can be shown in different languages, this can only be set at the factory and therefore must be specified at the time of placing an order. Programming 3.8.1 Programming Notes Programs can be created in Level 1 or Level 2 of the 3508 Controller.
3.0 3508 Controller To alter parameters or segments of an operating program, this program must be held or reset. Press RUN/ HOLD to pause the program, or press RUN/ HOLD for 2 seconds to reset. 3.8.2 Holdback Holdback can be used to prevent the program from operating ahead of the actual heating or cooling.
3.0 3508 Controller 4. ‘Dev Lo’ Wait until the measured temperature drops below a fixed* threshold by an amount ‘WaitVal’ set for that segment. * The fixed threshold used by deviation parameters is set in the configuration level of the programmer and if required should be requested when purchasing a product from Carbolite Gero.
3.0 3508 Controller Holdback Type Press scroll until the display shows 'Holdback Type'. If required, press up or down to select 'Off', 'Low', 'High' or 'Band'. Target Setpoint (Visible only for Rate, Time and Step segments) Press scroll until the display shows 'Target SP'. Press up or down to set a value.
3.0 3508 Controller 3.8.7 To pause (hold) a program Press RUN/HOLD Press page until 'Program Status Reset' appears Press scroll until the cursor moves to 'Reset' Press up or down to select 'Hold' RUN/HLD will be displayed 3.8.8 To stop and reset a program Press and hold RUN/HOLD Press page until 'Program Status Reset' appears...
3.0 3508 Controller Current program number (P10 and P25 only) Current segment number Time remaining for that segment Further presses of the scroll key while a program is operating will reveal additional information: Status. This can be changed to 'Hold', 'Reset' or 'Run' by pressing up or down Program Setpoint (PSP) Current Segment Type.
3.0 3508 Controller ALM (Alarm) indicator. The alarm may also switch an output – usually a relay to allow external devices to operate when an alarm occurs. Alarms only operate if they have been configured and are dependent on customer requirements. How to acknowledge an alarm will depend on the type of latching which has been configured.
Page 25
3.0 3508 Controller 12. Press scroll until 'End Type' is displayed. Press up or down to select 'Reset' 13. Press page and scroll together to return to the home display. To run the program either press RUN/HOLD or: 14. Press page until 'Program Status' is displayed 15.
Page 26
3.0 3508 Controller Time Display Examples 10:05:3 Min/Sec/10th Sec 21:10:05 Hour/Min/Sec 196:10 Hour/Min Segment Type 'Rate' Type 'Dwell' Type 'Step' Type 'Dwell' Type 'Time' Type 'End' Target 400°C Duration 30 min Target 600° Duration 30 min Target 200° End Type 'Reset' Rate 5.0°/Min Time 120 min 3.8.15 Program Example 2...
Page 27
3.0 3508 Controller 5. Press scroll until 'Cycles' is displayed. Default ‘1’ 6. Press scroll until 'Segment 1' is displayed 7. Press scroll until 'Segment Type' is displayed. Press up or down to select ‘Time’ 8. Press scroll until 'Holdback Type' is displayed. Default ‘Off’ 9.
3.0 3508 Controller Segment Type 'Time' Type 'Rate' Type 'Step' Type 'Dwell' Type 'Call' Type 'End' Target 600°C Target 400°C Target 200°C Duration 30 min Call prog 3 End Type 'Dwell' Duration 30min Rate 2°C/min H back type 'High' Call cycles 2n * Segment 4 'Holdback Value' 5°C ** P10 and P25 only *** Program 3 Example...
3.0 3508 Controller 3.9.1 Digital Communications - RS232 If the RS232 option is supplied, the furnace is fitted with one sub-miniature D- socket connected to the controller comms module. RS232 is suitable for direct connection to a personal computer (PC) using a “straight through” cable as follows (the linked pins at the computer end are recommended but may not be necessary).
3.0 3508 Controller Temperature Controller Fuse (2A) Supply Load Normally open relay contacts Relay Output 240V 2A The purpose of the 2 amp fuse is to break the circuit to prevent overloading on the circuit due to high voltage. The instrument configuration and parameters available to the operator depend on the customer requirements.
3.0 3508 Controller set to on, then the relay closes during the segment and a small 1 appears in the top left of the screen. If more than one program segment output is fitted, then there are extra boxes depending on how many event outputs there are. 3.10 Temperature Controller Replacement Before handling the controller: wear an anti-static wrist strap or...
3.0 3508 Controller 3.11.1 Operator Level 1 - No Program Running Home Display Controller identity when using more than one controller Read Only Black = Progress Page Key White = Return Scroll Key Visible Parameters depend on the Segment Type...
3.0 3508 Controller 3.11.2 Operator Level 1 - Program Running Home Display Controller identity when using more than one controller Read Only Black = Progress Page Key White = Return Scroll Key See previous diagram: Operator Level 1- No Program Running...
3.0 3508 Controller 3.11.3 Supervisor Level 2 To enter Level 2 Scroll Key Level 2 Locked before Pass Code entered Level 1 Home Display Unlocked Level 2 Home Display Black = Progress See previous diagram: Page Key Operator Level 1- No Program Running Hold Page Key for 3 seconds If configured Arrow Key...
4.0 3508 Dual Loop Cascade 4.0 3508 Dual Loop Cascade Control (if fitted) Principle of Cascade Control When cascade control is fitted, the Load Loop 3508 senses the temperature of the workload, and the Element Loop 3508 senses the element temperature. Depending on the oven or furnace model, the Load Thermocouple may be in a fixed position, or may be movable.
Page 36
4.0 3508 Dual Loop Cascade Home Display View Load Loop View Element Loop View The Element Loop should never be adjusted. Note that the elements usually run at a higher temperature than the load.
Page 37
4.0 3508 Dual Loop Cascade Because the details of the customer’s cascade application (in particular the nature of the load) are generally not known, the feed forward parameter (FF Trim) is made easily accessible in level 2 (Refer to instrument operating instructions). Its default setting is 2%.
Page 38
4.0 3508 Dual Loop Cascade Power Limit View...
4.0 3508 Dual Loop Cascade Bypassing Cascade Control This applies where the Control Thermocouple is a removal probe (e.g. in a tube furnace), or where for other reasons it may be required to operate the furnace or oven directly from the Element Loop. To operate without Cascade Control the load thermocouple has to remain connected at all time;...
5.0 2132 Over-Temperature 5.0 2132 Over-Temperature Controller Description (if fitted) Description Alarm Light Page Scroll D Down Display This over-temperature controller is fitted and supplied ready to use by Carbolite Gero. It is a digital instrument with a latching alarm, requiring no additional panel controls. The controller features easy setting of over-temperature setpoint and reading of current temperature by the over-temperature sensor.
5.0 2132 Over-Temperature 5.2.2 Operation When switched on, the controller lights up, goes through a short test routine and then displays the measured temperature or the over-temperature setpoint. The page key allows access to parameter lists within the controller. A single press of the page key displays the temperature units, normally set to °C;...
5.0 2132 Over-Temperature Audible Alarm If an audible alarm is supplied for use with the over-temperature controller, it is normally configured to sound on over-temperature condition and to stop sounding when the alarm is acknowledged as given in section 5.2. Note: the alarm may sound during controller start-up.
6.0 Operation 6.0 Operation Operating Cycle This product is fitted with an instrument switch which cuts off power to the control circuit. Connect the product to the electrical supply. The cooling fans should automatically operate. The furnace is fitted with a pair of gates that have a safety switch. the hearth can only be lowered or raised if the gates are closed.
6.0 Operation When heating large objects, in particular poor conductors, avoid shielding the thermocouple from the heating elements. The thermocouple is intended to sense the temperature near the heating elements. However, if a large object is placed in the chamber it may record the average temperature of the object and the elements, this can lead to overheating of the elements.
6.0 Operation Operator Safety This product incorporates a safety switch which interrupts the heating element circuit when the furnace is opened. This prevents the operator touching a live heating element and also prevents the product from heating up if the furnace is left open. The operation of this switch should be checked periodically.
6.0 Operation Operators are advised to periodically check the thermocouple output, either by a calibration test or by comparing the output with a new reference thermocouple which has been subjected to high temperatures for a minimum length of time. Failure to check the thermocouple regularly may result in overheating of the work and the furnace, with consequential damage to both.
7.0 Maintenance 7.0 Maintenance General Maintenance Preventive rather than reactive maintenance is recommended. The type and frequency depends on the product use; the following are recommended. Maintenance Schedule CUSTOMER QUALIFIED PERSONNEL DANGER! ELECTRIC SHOCK. Risk of fatal injury. Only electrically qualified personnel should attempt these maintenance procedures.
Page 48
7.0 Maintenance Function Tested using certified equipment, frequency Temperature Calibration dependent on the standard required Operational Check Check that all functions are working normally Thorough inspection and report incorporating a Operational Check test of all functions Performance Element Circuit Electrical measurement Measure the current drawn on each phase / cir- Power Consumption cuit...
7.0 Maintenance 7.2.1 Cleaning Soot deposits may form inside the furnace, depending on the process. At appropriate intervals remove these by heating as indicated in the General Operation Notes. The product's outer surface may be cleaned with a damp cloth. Do not allow water to enter the interior of the case or chamber.
7.0 Maintenance Power Adjustment (Thyristor) The current-limiting thyristor stacks which control power to the elements are fitted with an adjustable resistor which is factory set to limit the maximum current supplied. In the event of a change of supply voltage, or the fitting of a new thyristor, further adjustment may be required.
8.0 Repairs and Replacements 8.0 Repairs and Replacements Safety Warning - Disconnection from Power Supply Immediately switch the product off in the event of unforeseen circumstances (e.g. large amount of smoke). Allow the product to return to room temperature before inspection. Always ensure that the product is disconnected from the electrical supply before repair work is carried out.
8.0 Repairs and Replacements Safety Warning - Molybdenum Disilicide Elements Molybdenum disilicide elements form a glazed surface when heated. Internal stresses can form through heating and cooling which render the glaze fragile. The glaze can sometimes splinter into a shower of sharp particles when handled.
8.0 Repairs and Replacements Element Protection Tube Option Replacement Procedure Ensure the furnace is cold and isolated from the electrical connection. On the underside of the front cowl is a stainless steel mesh, which should be removed for access to the underside of the furnace. You will see three crescent shaped stainless steel brackets which will support the protection tube once in place;...
8.0 Repairs and Replacements Element Installation and Replacement See section 8.3 - Safety Warning - molybdenum disilicide. Molybdenum disilicide elements form a glazed surface when heated. Internal stresses can form through heating and cooling which render the glaze fragile. The glaze can sometimes splinter into a shower of sharp particles when handled.
Page 55
8.0 Repairs and Replacements Braid Roof Insulation Element block D Element Element Clamp See text Clip Braid Element Connections (3-phase example)
Page 56
8.0 Repairs and Replacements Use of Clip Tool The distance from the top of the element clamp to the top of the element should be 40 mm. Larger clips require the clip tool, comprising two levers: 1. Clip tool 2. Apply hand pressure...
9.0 Fault Analysis 9.0 Fault Analysis Furnace Does Not Heat Up The HEAT An ohm meter applied to light(s) the element circuit shows A heating element has failed. are ON. an open circuit. The HEAT The controller shows a The thermocouple has broken or has light(s) very high temperature or a wiring fault.
9.0 Fault Analysis Product Overheats The HEAT light goes The controller OFF with the shows a very high The controller is faulty. instrument switch. temperature. The thermocouple may have The controller been shorted out or may shows a low have been moved out of the temperature.
Page 60
11.0 Fuses and Power Settings 11.0 Fuses and Power Settings 11.1 Fuses F1 to F3 - Refer to the circuit diagrams. GEC Safeclip of the type shown Fitted if supply cable fitted. Internal (glass type F up to 16 A) Supply Fitted on board to some types 38 mm x 10 mm type F fitted on...
Page 61
11.0 Fuses and Power Settings Please refer to the rating label for product specific information.
Page 62
12.0 Specifications 12.0 Specifications Carbolite Gero reserves the right to change the specification without notice. Approx. Chamber Size (mm) Max Temp Max Power Net Weight Capacity Model (°C) (kW) (kg) Height Diameter Bottom Loading Furnaces heated by Molybdenum Disilicide elements, with electrically operated hearth.
Page 63
Notes Service Record Engineer Name Date Record of Work...
Page 64
The products covered in this manual are only a small part of the wide range of ovens, chamber furnaces and tube furnaces manufactured by Carbolite Gero for laboratory and industrial use. For further details of our standard or custom built products please contact us at the address below, or ask your nearest stockist.
Need help?
Do you have a question about the CARBOLITE GERO BLF 18/3 and is the answer not in the manual?
Questions and answers