VERDER CARBOLITE GERO MTF 12/38/250 Manual

Installation, Operation and Maintenance Instructions
1200°C Small Tube Furnace - MTF Model: 250/400/850mm
No Controller
MTF 12/38/250-400-850 + No Controller
MEN-MTF1238-005_NOCTRL (10-01-2019)

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 Tube Fittings 8
2.4 Electrical Connections 9
3.0 Temperature Controller 11
4.0 2132 Over-Temperature Controller Description (if fitted) 12
4.1 Description 12
4.2 Operation 12
4.2.1 Controls 12
4.2.2 Operation 13
4.2.3 Over-Temperature Operation 13
4.2.4 Over-Temperature Alarm 13
4.2.5 Resetting the Over-Temperature Alarm 13
4.2.6 Sensor Break 13
4.3 Audible Alarm 14
4.4 Navigation Diagram 14
5.0 Operation 15
5.1 Operating Cycle 15
5.2 General Operating Advice 15
5.3 Operator Safety 16
5.4 Tube Life 16
5.5 Power Adjustment 16
5.6 Running at Low Temperatures 17
6.0 Maintenance 18
6.1 General Maintenance 18
6.2 Maintenance Schedule 18
6.2.1 Cleaning 20
6.3 Calibration 20
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6.4 After-Sales Service 20
6.5 Recommended Spare Parts and Spare Parts Kit 20
7.0 Repairs and Replacements 21
7.1 Safety Warning - Disconnection from Power Supply 21
7.2 Safety Warning - Refractory Fibre Insulation 21
7.3 Temperature Controller Replacement 21
7.4 Solid-State Relay Replacement 22
7.5 Thermocouple Replacement 22
7.6 Fuse Replacement 22
7.7 Element Replacement 24
8.0 Fault Analysis 25
A. Furnace Does Not Heat Up 25
B. Product Overheats 26
9.0 Wiring Diagrams 27
9.1 WA-11-30 27
10.0 Fuses and Power Settings 28
10.1 Fuses 28
10.2 Power Settings 28
11.0 Specifications 29
11.1 Environment 29
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1.0 Symbols and Warnings
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.
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Caution – Double Pole/Neutral Fusing
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1.0 Symbols and Warnings

2.0 Installation
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 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.
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.
A product ordered for vertical use has a small clip or plate at one end to prevent a
wound tube element or a work tube from slipping downwards.
Mount the product so that this clip is at the bottom. In models with one thermocouple
the thermocouple should be near the top rather than the bottom.
If the product is supplied with a separate work tube or any accessories fit these into
position.
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.
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2.0 Installation

2.0 Installation
2.3 Tube Fittings
For optimum temperature uniformity, insulating plugs should be placed in the tube ends
as shown in fig.1. With a long work tube, the stem of the plug assembly should line up
with the end of the tube as in fig.2. Alignment of radiation shields is similar to that of
plugs.
If stainless steel seals with gas inlets are supplied, they are to be fitted as shown in
fig.3; the stem of any insulating plug should touch the seal.
For vertical models with stainless steel seals, a hook and eye arrangement holds the
upper insulating plug assembly.
Horizontal models: if heavy fittings are to be clamped to the end of an extended work
tube they can increase the bending stress at the centre of the tube. Support such fittings
in such a way that expansion of the tube is allowed.
Fig 1 - Insulating Plug
(standard length tube) Key
A Tube
B Insulating Plug
C Stem
Fig 2 - Insulating Plug
(long work tube)
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Key
A Clamp
B Seal plate
C 'O' Ring seal
D Seal sleeve
E Clamp seal
F End plate
Key
A Clamp
B End plate
CClamp seal (between Seal
sleeve and Clamp
D Seal sleeve
ESeal plate & 'O' Ring seal
(underneath clamp)
F Tube
Fig 3 'Twin Clamp' End Seal
For assembly details refer to the separate work tube end seal manual.
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.
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2.0 Installation

2.0 Installation
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. A table of the most common fuse ratings is also given towards the back of this
manual. 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.
If the product is to be connected by line plug. The plug should be within reach of the
operator and should be easy to remove.
When connecting the product to an isolating switch ensure that both conductors (single
phase) or on all live conductors (three phase), and should be 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 L Brown to live
to either power
conductor
(For USA 200-240V,
connect L1)
N 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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3.0 Temperature Controller
If this product is fitted with a temperature controller, instructions are provided
separately.
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3.0 Temperature Controller

4.0 2132 Over-Temperature
4.0 2132 Over-Temperature Controller Description (if
fitted)
4.1 Description
Key
A Alarm Light
B Page
C Scroll
D Down
E Up
F 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.
4.2 Operation
4.2.1 Controls
Most Carbolite Gero products are fitted with an instrument switch which cuts off power
to the controller and other parts of the control circuit.
To operate the controller, power must be supplied to the product and the instrument
switch must be on. If a time switch is included in the product circuit, this must be in the
'ON' position.
When an over-temperature condition occurs, the controller cuts the power to a
contactor, which in turn cuts power to the heating elements. Power is not restored until
the controller is 'reset'.
Some components will operate after the over-temperature feature isolates the power
supply e.g. cooling fans will continue to operate, provided that there is a power supply
to the product. In some cases the product may not do so, if other options (such as a
door switch) are fitted.
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4.2.2 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;
further presses reveal the lists indicated in the navigation diagram. See section 4.4.
The scroll key allows access to the parameters within a list. Some parameters are
display-only; others may be altered by the operator.
A single press of the scroll key in the 'Home' list displays the temperature units;
further presses reveal the parameters in the current list indicated in the navigation
diagram.
To return to the 'Home' list at any time, press page and scroll together, or wait
for 45 seconds.
The down and up keys are used to alter the setpoint or other parameter values.
4.2.3 Over-Temperature Operation
Use down and up to alter the over-temperature setpoint. This should normally be
set a little above the working temperature (for example 15 °C above). The product is
supplied with the over-temperature set at 15 °C above the furnace or oven maximum
working temperature.
Press scroll twice view the present temperature as measured by the over-
temperature controller. Press it twice, the first press shows the temperature units (°C).
4.2.4 Over-Temperature Alarm
If an over-temperature condition occurs, the OP2 indicator flashes and an alarm
message 2FSH also flashes, alternating with the setpoint. Power to the heating
elements is disconnected.
4.2.5 Resetting the Over-Temperature Alarm
To acknowledge the alarm press scroll and page together.
If the alarm is acknowledged while there is still an over-temperature condition, the OP2
indicator stops flashing but continues to glow. The 2FSH alarm continues to flash until
the over-temperature condition is cleared (by the temperature falling), when normal
operation resumes.
If the alarm is acknowledged when the temperature has dropped (or after the over-
temperature setpoint has been raised) so that the over-temperature condition no
longer exists, then the furnace or oven immediately resumes normal operation.
4.2.6 Sensor Break
The over-temperature cut-out system also operates if the over-temperature control
thermocouple breaks or becomes disconnected. The message S.br flashes where the
measured temperature is normally displayed.
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4.0 2132 Over-Temperature

4.0 2132 Over-Temperature
4.3 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 4.2.
Note: the alarm may sound during controller start-up.
4.4 Navigation Diagram
HL Home List Page Key Black = Progress
OTSP Over-Temperature
Setpoint Scroll Key
Dashed = Through to
other options
AL Access List For factory access to list and parameters not
available to the operator.
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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.
There is also a heater switch which can be used to disconnect power to the elements.
Operate the instrument switch to activate the temperature controller. The controller
becomes illuminated and goes 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.
The product will heat up according to the controller setpoint or program, unless a time
switch is fitted and switched off.
As the product heats up, the heat light glows steadily at first and then flashes as the
product approaches the desired temperature. For more information on temperature
control see the controller instructions.
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.
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.
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5.0 Operation

5.0 Operation
5.3 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.
5.4 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.
5.5 Power Adjustment
The product control system incorporates electronic power limiting. The power limit
parameter OP.Hi is accessible to the operator and can be used to adjust the product to
the actual supply voltage.
Some models covered by this manual are fitted with 208 V elements and are designed
for use over the range of voltages 200 V- 250 V; the power limit parameter is set
accordingly. These models may be relocated to a different voltage within the range: the
power limit should be reset to match the voltage.
To check whether the furnace is a 208 V model:
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llook at the OP.Hi parameter
lmake a note of the value and compare with the 10.0;
lobserve the rating label; if a range of voltages is stated, it is not a 208 V multi
voltage model;
lif in doubt, check with Carbolite Gero – each product has its own record card.
Refer to the controller instructions for how to change the power limit.
5.6 Running at Low Temperatures
The power limit may be adjusted to a low level in order to achieve better control when
operating the product at a low temperature. Before changing the power limit, record
the default settings for possible future use. Refer to the Power Settings section of this
manual for default power limits. If the product fails to reach the desired temperature,
refer to the Temperature Controller and Fault Analysis sections.
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5.0 Operation

6.0 Maintenance
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
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 ambient,
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 clean-
ing 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 nor-
mally
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 / vertically)
End Plugs / Radiation Shields Visual check for damage or wear, and cor-
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rect 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 work-
ing
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6.0 Maintenance

6.0 Maintenance
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 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.
6.4 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.
6.5 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 and one heating element.
When ordering spare parts please quote the model details as requested above.
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