VERDER Carbolite Gero SCF 24 Manual

Installation, Operation and Maintenance Instructions
1200 °C Smelting Crucible Furnace - SCF Model: 24
No Controller
SCF 24 + No Controller
MEN-SCF24-005_NOCTRL (30-03-2023)
ORIGINAL: ENGLISH

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. Use the product for the purpose for which it is intended.
1.0 Symbols and Warnings 4
1.1 Switches and Lights 4
1.2 General Warnings 4
1.3 Prerequisites to Use 5
2.0 Installation 6
2.1 Unpacking & Handling 6
2.2 Siting and Setting Up 6
2.3 Hearth 7
2.4 Extraction 7
2.5 Electrical Connections 8
2.6 Voltage and Power Limit 9
3.0 Temperature Controller 10
4.0 Time Switch 11
4.1 Digital Time Switch - Theben TR 635 top2 11
Important Note 12
Reset 12
Setting the Time and Date (and Daylight Saving Rules) 12
Setting a Switch-On or Switch-Off Time 12
Modifying or deleting a Switch-On or Switch-Off Time 12
Overriding the Program 13
Pulse and Cycle 13
5.0 Operation 14
5.1 Operating Cycle 14
5.2 General Operating Advice 15
5.3 Operator Safety 15
5.4 Over-Temperature Control (if fitted) 15
6.0 Maintenance 17
6.1 General Maintenance 17
6.2 Maintenance Schedule 17
6.2.1 Cleaning 19
6.3 Safety Switch 19
6.4 Calibration 19
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6.5 After-Sales Service 20
6.6 Recommended Spare Parts and Spare Parts Kit 20
6.7 Element Ageing 20
6.8 Power Adjustment 21
7.0 Repairs and Replacements 22
7.1 Safety Warning - Disconnection from Power Supply 22
7.2 Safety Warning - Refractory Fibre Insulation 22
7.3 Temperature Controller Replacement 22
7.4 Solid-State Relay Replacement 23
7.5 Element Fitting and Replacement 24
7.6 Thermocouple Replacement 25
7.7 Fuse Replacement 25
8.0 Fault Analysis 26
A. Furnace Does Not Heat Up 26
B. Product Overheats 27
9.0 Wiring Diagrams 28
10.0 Fuses and Power Settings 29
10.1 Fuses 29
10.2 Power Settings 29
11.0 Specifications 30
11.1 Environment 30
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1.0 Symbols and 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 General Warnings
DANGER – Electric shock. Read any warning printed next to this
symbol.
WARNING: Risk of fatal injury.
DANGER – Hot surface. Read any warning printed next to this
symbol.
WARNING: All surfaces of a product may be hot.
DANGER – Read any warning printed next to this symbol.
Caution – Double Pole/Neutral Fusing
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1.3 Prerequisites to Use
Prior to the commissioning and use of this product, all personnel involved in its
installation, operation and maintenance must be deemed competent and have:
lRead and understood the information contained within this manual
lReceived the relevant training with regard to safety and operation of the product
lBeen provided with the appropriate PPE (Personal Protective Equipment) required
for the safe operation of this product
Note: The customer is responsible for ensuring that all of the above conditions are
satisfied before the product is commissioned for use.
Note: Unless otherwise specified, the customer is responsible for the
installation of this product and the safe connection of any additional
equipment and gas or liquid supply lines.
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2.0 Installation
2.1 Unpacking & Handling
When unpacking or moving the product, always lift by its base; do not use the door or
any other projecting cover or component to support the equipment when moving it. Use
a fork lift or pallet truck to move the product; position the product on a level surface
and use an adequate number of personnel to safely move the product into position.
Carefully remove any packing material from inside and around the product before use.
Avoid damaging the surrounding insulation when removing packing materials.
Note: This product contains Refractory Ceramic Fibre (also known
as Alumino Silicate Wool - ASW). For precautions and advice on
handling this material see section 7.2.
2.2 Siting and Setting Up
Place the product on a level surface in a well ventilated area.
Site away from other sources of heat and on a non-flammable surface that is resistant
to accidental spillage or hot materials.
The surface on which the equipment is mounted should be stable and not subject to
movement or vibrations.
The height of the mounting surface is important to avoid operator strain when loading
and unloading samples.
Unless otherwise stated elsewhere in this manual, ensure that there is at least 150
mm of free space around the back and sides of the product. Clear space is required
above the product to dissipate heat.
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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.
Under no circumstances should any objects be placed on top of the
product. Always ensure that any vents on the top of the product are clear
of any obstruction. Always ensure all cooling vents and cooling fans (if
fitted) are clear of any obstruction.
2.3 Hearth
The hearth and chamber are supported during transport by packing foam. Remove and
dispose of this packaging.
2.4 Extraction
If the product is to be used to heat substances that emit fumes, a fume extraction duct
may be placed directly above the furnace.
Do not make a sealed connection to the product chimney as this causes excessive
airflow through the chamber and results in poor temperature uniformity.
A heatproof drip tray will be supplied to prevent corrosion to the floor underneath the
furnace. The tray should be placed directly under the air inlet as shown in the image
below.
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2.5 Electrical Connections
Connection by a qualified electrician is recommended.
The model covered in this manual has three internal circuits and is normally supplied
for connection to a three phase power supply. This may be either star or delta, but a
product must only be connected to the type and voltage of supply for which it was
made. If the product is ordered for a single phase supply, this may be Live to Neutral
reversible or non-reversible, or Live to Live.
Check the product rating label before connection. The supply voltage should agree with
the voltage on the label and the supply capacity should be sufficient for the current on
the label.
The supply should be fused at the next size equal to, or higher than the current on the
label. This manual contains a table of the most common fuse ratings.
When the mains cable is factory fitted, internal fuses are also fitted. It is essential that
the operator ensures that the product is correctly fused.
Products with a factory fitted supply cable are designed to be wired directly to an
isolator or fitted with a line plug.
Products without a factory fitted supply cable require a permanent connection to a
fused and isolated supply. The product's electrical access panel should be temporarily
removed, and connections made to the internal terminals.
When connecting the product to the power supply, the plug or isolating switch should
be accessible, easy to remove, and within reach of the operator.
The supply MUST incorporate an earth (ground).
Supply Terminal Label Cable Colour
Supply Types
Live - Neutral Reversible or Live-
Live
1-phase L1 Brown to live
to either power
conductor
(For USA 200-240V,
connect L1)
N / L2 Blue to neutral
to the other power
conductor
(For USA 200-240V,
connect L2)
PE Green/ Yellow to earth
(ground) to earth (ground)
Electrical Connection Details:
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2- or
3-phase L1 Black to phase 1
L2 Black to phase 2
L3 Black to phase 3 (except 2-phase)
N Light Blue to neutral (except delta)
PE Green/ Yellow to earth (ground)
2.6 Voltage and Power Limit
When first starting up the product, check the setting of the OP.Hi
parameter (see the controller instructions) and compare it with
the data in section 10.0 towards the back of this manual.
If the power limit setting is incorrect for the voltage of the electrical supply, change it.
This must be done immediately if the setting of OP.Hi is higher than it should be.
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3.0 Temperature Controller
If this product is fitted with a temperature controller, instructions are provided
separately.
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4.0 Time Switch
4.1 Digital Time Switch - Theben TR 635 top2
The Theben TR 635 top2 is a 7 day
digital time switch with 84 memory
locations each of which can contain a
switching time for any or all or the days
in a week. It is battery backed with
approximately 10 years power reserve.
The shortest switching interval is 1
minute.
A choice of languages is included. There
is a real-time clock and a choice of
daylight saving rules.
The facia features a digital display and
four buttons as shown in the image.
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Important Note
In the instructions below, "select" an item means the following:
Press the arrow keys (usually the right) until the item appears on the screen. Then
press OK.
Reset
To reset press all four buttons simultaneously all stored programs can be retained or
deleted. Normally avoid reset except to change the language, as follows.
Press all four buttons simultaneously. Then select the required language.
Set the time and date by pressing the arrow keys and using OK. After changing
language it may be necessary also to change the daylight saving rules: see the next
section.
Setting the Time and Date (and Daylight Saving Rules)
Press the MENU key then use the right arrow key to display TIME/ DATE and then press
OK. Use the arrow keys and OK to set the time and date.
After setting the date, the next display shows the current SU – WI selection. To alter
the daylight saving rules, press the arrow keys to select between six different countries
or FREE or FIX DATE or NO SU-WI.
If FREE is chosen, a month and date entry sequence is entered: follow the display
requests.
Setting a Switch-On or Switch-Off Time
A program entry comprises a function (on or off), a switching time and the days to
which it applies.
Press MENU.
PROGRAM is displayed. Press OK.
NEW is displayed. Press OK.
Use the arrow keys to select ON (for switch on times) or OFF (for switch off times).
Press OK.
HOUR is displayed. Use the keys to enter hour, minute and confirm by pressing OK.
MONDAY is displayed. Select the day required then press OK.
COPY is displayed. Press OK to copy the switching time to other days or use the arrow
key to select SAVE.
Other choices are CHECK, MODIFY, CLEAR or END.
Modifying or deleting a Switch-On or Switch-Off Time
Press MENU.
PROGRAM is displayed. Press OK.
NEW is displayed. Use the arrow keys to select CHECK, MODIFY or DELETE. Press OK
after selecting one of these options. If modifying confirm MODIFY HOUR by pressing
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OK. The first of the switching times is shown. Use the keys to adjust the time and
confirm by pressing OK.
Once the date and time memories are entered, the time switch automatically obeys
them. Note that if the same time is used for an on as an off, off takes priority.
Overriding the Program
To change the present state between on and off, press MENU, select MANUAL. Within
the MANUAL choices are PERMANENT ON; PERMANENT OFF; MANUAL ON; TIMER;
HOLIDAY; RANDOM & END.
Avoid random, which is irrelevant to furnaces. The holiday feature may be left as an
exercise for the reader.
Pulse and Cycle
These features are not required and should be off.
Note: If the furnace is fitted with a CC-T1, instead of starting a program, the time
switch will turn the CC-T1 on or off.
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5.0 Operation
5.1 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.
Turn on the instrument switch to activate the temperature controllers. The controllers
illuminate and go through a short test cycle.
This product if fitted with a time switch which operates in conjunction with the
temperature controller as follows:
Temperature
Controller Time Switch Function Operation
301
Controller
Time switch cuts power to the
temperature controller
Switch on the instrument switch.
Set the required setpoint on the
temperature controller.
Timer in 'OFF' state: furnace does not
heat.
Timer in 'ON' state: furnace heats to
the setpoint.
3016
Programmer
or
3008
Programmer
or
CC-T1
Time switch starts a
temperature program
Switch on the instrument switch.
Set the required temperature program
in the temperature controller.
Timer in 'ON' state: the program is
started.
Timer in 'OFF' state: the program is
stopped.
Set the time switch as required.
Set the element over-temperature controller to approximately 100 °C above the
maximum or setpoint temperature. The element over-temperature controller protects
the heating elements from excessive temperature and if activated is self resetting.
When correctly set it may be ignored (see section 0.1).
Chamber Over-Temperature option only. If the digital over-temperature option has
not yet been set as required, set and activate it according to the over-temperature
controller instructions.
Unless the time switch is switched off, the product starts to heat up according to the
controller setpoint or program.
Chamber Over-Temperature option only. If the over-temperature circuit has
tripped, an indicator on the over-temperature controller flashes and the heating
elements are isolated. Find and correct the cause before resetting the over-temperature
controller according to the instructions supplied.
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To turn the product off, set the instrument switch to its off position. The controller
display will go blank. If the product is to be left unattended, isolate it from the
electrical supply.
5.2 General Operating Advice
Heating element life is shortened by overheating. Do not leave the
product at high temperature when it is not required. The maximum
temperature is shown on the product rating label and in section 11.0
towards the back of this manual.
Lightweight ceramic fibre insulation can easily be marked by
accidental contact. Some fine cracks may develop in the surface of
the insulation due to the progressive shrinkage of the insulation
materials. Cracks are not usually detrimental to the functioning or
the safety of the product.
Clean up any spillages in the insulation, as these can increase the rate of degradation
of the insulation material.
5.3 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.
Depending on use, the surfaces in the working chamber and the
chamber load may still be very hot after the appliance is switched
off. Touching these surfaces may cause burns. Use suitable personal
protective equipment or wait until the appliance cools down to
ambient temperature.
Before removing a hot object from the product, make sure there is a safe place to put
it down. If necessary use tongs, face masks and heat resistant gloves. Heat resistant
clothing and face protection can guard against the effects of radiated heat when the
furnace is open.
When the product is opened during operation there is considerable radiated heat. Do
not keep any flammable objects near the product, nor objects which could be damaged
by radiated heat.
5.4 Over-Temperature Control (if fitted)
The over-temperature controller should typically be set at 15 °C above the main
controller. If an over-temperature condition occurs, check the main controller is
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functioning correctly.
An over-temperature condition cuts off power to the heating elements. A light in the
over-temperature controller flashes. To reset this, refer to the over-temperature control
section of this manual.
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6.0 Maintenance
6.1 General Maintenance
Preventive rather than reactive maintenance is recommended. The type and frequency
depends on the product use; the following are recommended.
6.2 Maintenance Schedule
CUSTOMER
QUALIFIED PERSONNEL
DANGER! ELECTRIC SHOCK. Risk of fatal injury. Only electrically
qualified personnel should attempt these maintenance procedures.
Maintenance
Procedure Method
Frequency
Daily Weekly Monthly Bi-
Annually Annually
Safety
Safety Switch Function
Set a safe temperature above ambient, and
open the lid to see if the heater light goes
out
Safety Switch Function Electrical measurement
Over-Temperature Safety
Circuit
(if fitted)
Set an over-temperature setpoint lower
than the displayed temperature and check
for an over-temperature alarm as detailed in
this manual
Over-Temperature Safety
Circuit
(if fitted) Electrical measurement
Lid Insulation Visual inspection, checking the seal and
whether it is free of damage
Lid Insulation Replacement where necessary
Chimney / Extraction Check and clean if necessary
Electrical Safety
(external) Visual check of external cables and plugs
Electrical Safety (internal) Physically check all connections and clean-
ing of the power plate area
Function
Temperature Calibration Tested using certified equipment, frequency
dependent on the standard required
Operational Check Check that all functions are working nor-
mally
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Operational Check Thorough inspection and report incor-
porating a test of all functions
Performance
Element Circuit Electrical measurement
Power Consumption Measure the current drawn on each phase /
circuit
Hearth Visual check for fit and damage
Element Protection Tiles
Check for large cracks which could lead to
contamination of the elements causing pre-
mature failure.
Hearth and TopElement
Protection Tiles
When large gaps form in the element pro-
tection tiles they need to be replaced to pre-
vent premature failing of the elements.
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6.2.1 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. Do not
clean with organic solvents.
6.3 Safety Switch
When correctly functioning, the safety switch will isolate all live conductors (live and
neutral connections) within the heating element circuit(s) when the product door is
opened. The safety switch should be checked regularly to ensure that this occurs.
The safety switch should not fail under normal working conditions, however rough
handling, exposure to corrosive materials/ environments, or exceptionally frequent
use, could compromise the safety system.
Weekly check:
The following check can be carried out by a general operator:
lOn the temperature controller, set a safe temperature above ambient. The heater
lights should illuminate.
lOpen the door and check the heater lights. They should no longer be illuminated.
If the heater lights remain illuminated when the door is open, discontinue use and
contact Carbolite Gero Service.
Annual check:
The following checks should be carried out by a qualified electrician, as specified in the
"Maintenance Schedule" section of this manual:
lRemove the element access panel and take a voltage measurement from the heat-
ing element terminals. Do not attempt to take a reading from the heating element
itself as surface oxidation will give an unreliable contact.
lEnsure that power to the heating elements is switched off when the door is opened.
Contact Carbolite Gero Service and discontinue use of the product if it is found that the
heating elements are not fully isolated during these checks.
6.4 Calibration
After prolonged use, the controller and/or thermocouple may require recalibration. This
is important for processes that require accurate temperature readings or for those that
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use the product close to its maximum temperature. A quick check using an independent
thermocouple and temperature indicator should be made from time to time to
determine whether full calibration is required. Carbolite Gero can supply these items.
Depending on the controller fitted, the controller instructions may contain calibration
instructions.
6.5 After-Sales Service
Carbolite Gero Service has a team of Service Engineers who can offer repair, calibration
and preventive maintenance of furnace and oven products both at the Carbolite Gero
factory and at customers’ premises throughout the world. A telephone call or email
often enables a fault to be diagnosed and the necessary parts to be despatched.
In all correspondence please quote the serial number and model type given on the
rating label of the product. The serial number and model type are also given on the
back of this manual when supplied with the product.
Carbolite Gero Service and Carbolite Gero contact information can be found on the
back page of this manual.
6.6 Recommended Spare Parts and Spare Parts Kit
Carbolite Gero can supply individual spare parts or a kit of the items most likely to be
required. Ordering a kit in advance can save time in the event of a breakdown.
Each kit consists of one thermocouple, one sheath, one solid-state relay, one door
insulation piece, a set of elements, a set of element clips and a set of braids and clips.
Individual spare parts are also available.
When ordering spare parts please quote the model details as requested above.
6.7 Element Ageing
Silicon carbide elements gradually increase in resistance with use; a process known as
ageing. Their heating power reduces correspondingly. To ensure sufficient power to the
product, it may be necessary to adjust the power limit and, ultimately, replace the
elements - taking care to readjust the power limit.
Note: A clamp meter should be used when adjusting the power limit to ensure that
the current is not inadvertently increased beyond safe limits. Please contact Carbolite
Gero Service for guidance on safe current limits.
If the product does not reach temperature, or is slow, check the power limit setting and
increase the value by 5%. It is recommended to make a note of the new settings and
the date of the adjustment in section 10.0. Increase the power limit in steps of 5% until
the product regains its original performance.
If the power limit is set to 100% a new set of heating elements is required.
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