VERDER CARBOLITE GERO CFM 14/2 Manual

Installation, Operation and Maintenance Instructions
1400°C Combustion Tube Furnace - CFM Model:14/2
No Controller
CFM 14/2 + No Controller
MEN-CFM1402-005_NOCTRL (18-10-2021)

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
2.0 Installation 6
2.1 Unpacking and Handling 6
2.2 Siting and Setting Up 6
2.3 Heating Elements 7
2.4 Electrical Connections 8
3.0 Temperature Controller 10
4.0 Operation 11
4.1 Operating Cycle 11
4.2 General Operating Advice 11
4.3 Tube Life 12
4.4 Operator Safety 12
4.5 Pressure 13
5.0 Maintenance 14
5.1 General Maintenance 14
5.2 Maintenance Schedule 14
5.2.1 Cleaning 16
5.3 Calibration 16
5.4 After-Sales Service 16
5.5 Recommended Spare Parts and Spare Parts Kit 16
5.6 Power Adjustment 16
5.7 Element Ageing 17
6.0 Repairs and Replacements 18
6.1 Safety Warning - Disconnection from Power Supply 18
6.2 Safety Warning - Refractory Fibre Insulation 18
6.3 Temperature Controller Replacement 18
6.4 Solid-State Relay Replacement 19
6.5 Thermocouple Replacement 19
6.6 Element Fitting and Replacement - 1400 °C Models 20
6.7 Fuse Replacement 21
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7.0 Fault Analysis 22
A. Furnace Does Not Heat Up 22
B. Product Overheats 23
8.0 Wiring Diagrams 24
8.1 WA-11-10 24
8.2 WA-11-11 25
8.3 WA-11-30 26
9.0 Fuses and Power Settings 27
9.1 Fuses 27
9.2 Power Settings 27
User Power Setting Adjustments 28
10.0 Specifications 29
10.1 Environment 29
3

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.
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 product.
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.
4

Caution – Double Pole/Neutral Fusing
5

2.0 Installation
2.1 Unpacking and Handling
When unpacking or moving the product 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. Use two or more
people to carry the product and control box. Remove any packing material from inside
the product before use.
If an optional or special stand is separately supplied, assemble the product on to it.
Some models may be supplied for customer mounting and may require customer
preparation of mounting components before installation.
NOTE: This product contains Refractory Ceramic Fibre (also known
as Alumino Silicate Wool - ASW). For precautions and advice on
handling this material see section 6.2.
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.
Work tubes:
It is recommended that the work tube has either insulation plugs or
radiation shields fitted to minimise heat loss from both ends of the work
tube. If the work tube has open ends, a significant amount of energy
could be radiated from the ends of the work tube. Adjacent surfaces
should always be made from a non-flammable material.
Ensure that the ends of the work tube are positioned at least 500 mm
away from any adjacent surface so that any energy radiated cannot heat
an adjacent surface to a dangerous temperature.
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Ensure that the product is placed in such a way that it can be quickly switched off or
disconnected from the electrical supply.
The product is typically used for sulphur and chlorine test in accordance with BS1016
parts 6 & 7, ASTM D 3177-75; ISO 351 & 609.
Please refer to the appropriate documentation.
This manual only gives general guidance common to tube products.
Fit any work tube(s) ordered into place. If a metal work tube is being used in the
product, ensure that it is earthed and that it is mounted so as not to touch the products
ceramic tube or insulation.
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 Heating Elements
The silicon carbide elements are VERY FRAGILE and are packed separately. Fit them
accordingly to the instructions in section 6.0 for element fitting and replacement
instructions.
7

2.4 Electrical Connections
Connection by a qualified electrician is recommended.
This product requires a single-phase A.C. supply with earth (ground), which may be
Live to Neutral non-reversible (polarised), Live to Neutral reversible (non-polarised), 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:
Technical Notes
8

This model has an electronically controlled power limit. 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 Gero if in doubt.
9

3.0 Temperature Controller
If this product is fitted with a temperature controller, instructions are provided
separately.
10

4.0 Operation
4.1 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.
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.
Switch on the heater switch, located on the instrument panel. Unless a time switch is
fitted and is switched off, the product will start to heat up. The Heat light(s) glow
steadily at first and then flash as the product approaches the desired temperature or a
program setpoint.
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.
To switch off power to the heating elements, use the heater switch. To switch the
product off, use both the heater switch and the instrument switch. If the product is to
be left switched off and unattended, isolate it from the electrical supply.
4.2 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 10.0
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.
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4.3 Tube Life
A ceramic work tube may crack if work pieces are inserted too quickly or at
temperatures below 900 °C (when the tube is more brittle). Large work pieces
should also be heated slowly to ensure that large temperature differences do not
arise.
Poor thermal contact should be encouraged between the work piece 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).
Key
A Tube
B Crucible
Fig 4 - Avoidance of thermal contact
Do not set too high a heating or cooling rate. As tubes are susceptible to thermal shock
and may break. Tubes which extend beyond the heated part of the furnace are more at
risk. A general rule for maximum heating or cooling rate is 400 ÷ internal diameter in
mm to give (°C/ min); for 75 mm i/ d tubes this comes to 5 °C per minute. The
controller can be set to limit both the heating and cooling rate.
4.4 Operator Safety
The ceramic materials used in the product manufacture become
electrically conductive to some extent at high temperatures. DO NOT
use any conductive tools within the product without isolating it. If a
metal work tube is used, it must be earthed (grounded).
Switch off the heater switch whenever loading or unloading the
product. The elements are isolated when the heater switch is OFF.
This switch cuts both sides of the circuit via a contactor.
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4.5 Pressure
Work tubes are not intended to accept high internal pressure. When gas
seals or similar fittings are in use, the gas pressure should be restricted to
amaximum of 0.05 bar (50mbar). A pressure of approximately half of
that should normally be sufficient to achieve the desired flow rate. The
operator must ensure that the exhaust path from the tube is not blocked,
so that excess pressure does not occur.
lA suitably regulated gas supply should always be used.
lIt is recommended that a pressure relief system should be used to avoid an over
pressurisation of the work tube.
Note: A product should not be heated up if any valves that have been fitted are
closed to create a sealed volume. A sealed work tube should not be heated from cold
due to the pressure increase caused by the trapped air or gas expanding during the
heating process.
Note: To minimise the increase of back pressure, always increase the
pipe diameter of any room vent lines when connecting to a product
exhaust outlet. For example, 6mm outlet connections should be
increased to a diameter of 10mm or greater for room lines between 5 -
10 metres in length.
Note: Always maintain clean gas lines. Regularly inspect vent lines
connected to the exhaust outlet as any build up of debris may increase
the back pressure of the vessel/ work tube.
13

5.0 Maintenance
5.1 General Maintenance
Preventive rather than reactive maintenance is recommended. The type and frequency
depends on the product use; the following are recommended.
5.2 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
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
Safety Switch Function
(split models only)
Set a safe temperature above ambi-
ent, and open the furnace to see if
the heater light goes out
Safety Switch Function
(split models only) Electrical measurement
Electrical Safety (external) Visual check of external cables and
plugs
Electrical Safety (internal) Physically check all connections and
cleaning of the power plate area
Function
Temperature Calibration
Tested using certified equipment, fre-
quency dependent on the standard
required
Operational Check Check that all functions are working
normally
Operational Check Thorough inspection and report incor-
porating a test of all functions
Work Tube Position
Visually check that the tube is central
to the heated zone (horizontally / ver-
tically)
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End Plugs / Radiation Shields Visual check for damage or wear, and
correct positioning
Seals (if fitted) Check all seals and O-rings and
clamps
Performance
Element Circuit Electrical measurement
Power Consumption Measure the current drawn on each
phase / circuit
Cooling Fans (if fitted) Check whether the cooling fans are
working
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5.2.1 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.
5.3 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
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.
5.4 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.
5.5 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 solid state relay, one heating element or set
of elements. For 1400 °C models the kits also include element clips and braids.
Individual spare parts are also available.
When ordering spare parts please quote the model details as requested above.
5.6 Power Adjustment
The product's control system incorporates electronic power limiting. Power is supplied
to the elements in bursts of approximately 0.33 seconds duration. This prevents
overheating of the elements. The power limit is programmed into the product
controller.
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A table of standard power limits is supplied with new products, it is given in section 9.0
5.7 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 9.0. 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.
Please note: it is not possible to use the cold resistance of the element as a measure
of ageing as the cold resistance is not an accurate indicator of hot resistance. Hot
resistance is used to calculate furnace power.
See the controller instructions for how to adjust the controller. Always record the
setting when first making an adjustment. If new elements are fitted, return the
adjustments to the original value. A table of standard power limits is given in section
9.0.
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6.0 Repairs and Replacements
6.1 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.
Caution: Double pole/neutral fusing may be used in this product.
6.2 Safety Warning - Refractory Fibre Insulation
Insulation made from High Temperature Insulation Wool
Refractory Ceramic Fibre, better known as (Alumina silicate
wool - ASW).
This product contains alumino silicate wool products in its thermal insulation. These
materials may be in the form of blanket or felt, formed board or shapes, slab or loose
fill wool.
Typical use does not result in any significant level of airborne dust from these
materials, but much higher levels may be encountered during maintenance or repair.
Whilst there is no evidence of any long term health hazards, it is strongly
recommended that safety precautions are taken whenever the materials are handled.
Exposure to fibre dust may cause respiratory disease.
When handling the material, always use approved respiratory protection
equipment (RPE-eg. FFP3), eye protection, gloves and long sleeved clothing.
Avoid breaking up waste material. Dispose of waste in sealed containers.
After handling, rinse exposed skin with water before washing gently with
soap (not detergent). Wash work clothing separately.
Before commencing any major repairs it is recommended to make reference to the
European Association representing the High Temperature Insulation Wool industry
(www.ecfia.eu).
Further information can be provided on request. Alternatively, Carbolite Gero Service
can quote for any repairs to be carried out either on site or at the Carbolite Gero
factory.
6.3 Temperature Controller Replacement
Refer to the controller instructions for more information on how to replace the
temperature controller.
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6.4 Solid-State Relay Replacement
Disconnect the product from the power supply and remove the
appropriate cover as given above.
1. Make a note of the wire connections to the solid state relay, then disconnect them.
2. Remove the solid state relay from the base panel or aluminium plate.
3. Replace and reconnect the solid state relay ensuring that the bottom of it has
good thermal contact with the base panel or aluminium plate.
4. Replace the access panel.
6.5 Thermocouple Replacement
Disconnect the product from the power supply. Remove the appropriate
panel to gain access to the thermocouple connections. Make a note of the
thermocouple connections.
Thermocouple cable colour codings are:
thermocouple leg colour
positive (type R) orange
negative white
Disconnect the thermocouple from its terminal block; retain any porcelain spacers.
Withdraw the thermocouple from its sheath and remove any broken bits of
thermocouple.
Re-assemble with a new thermocouple observing the colour coding.
Refit the element access panel.
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6.6 Element Fitting and Replacement - 1400 °C Models
Replacements: see section 5.7. If at any time the power limit has been increased, reset
it to its original value (see section 9.0 at the back of this manual for the original value).
New elements must not be mixed with aged elements. If a single heating element fails
within an element circuit containing aged elements, then all heating elements on that
circuit should be replaced. It may not be necessary to replace all heating elements
within a furnace, however the configuration of elements varies between products. If
required, please contact Carbolite Gero Service for advice.
Please provide the serial number of the furnace with all enquiries.
Disconnect the product from the electrical supply.
Remove the products end panels to gain access to the element connections.
The elements are expensive and fragile and can be damaged by contamination: handle
them with care and keep them clean.
Replacements only: make a note of the actual braid and cable connections to the
elements. Disconnect the clips with the special tool provided (or with finger pressure,
depending on the type of clips supplied), lift off the braids and carefully withdraw each
element. See fig. 5.
Carefully insert the new elements into the product.
Attach the connection braids according to the note made above or to the appropriate
diagram, fig. 6. Use the special tool (or finger pressure) to fit the clips. Take care that
adjacent clips do not touch each other.
Replace the products end guards and connect the product to the electrical supply.
If aged elements have been replaced, reset the product power limit.
Fig. 5. - Use of Clip Tool Fig. 6. - Element Connections
CFM 14/4: this model has 6 elements in series on 220 - 240 V. On 110 - 120 V these
are connected as two sets of 3 elements in series, in which case the L and N
connections are at opposite ends of the furnace.
20