VERDER CARBOLITE GERO STF 16/180 Manual

Installation, Operation and Maintenance Instructions
1600 °C Tube Furnace - STF Model: 180mm
No Controller
STF 16/180 + No Controller
MEN-STF16180-05_NOCTRL (17-07-2018)

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 Fitting 8
2.4 Heating Elements 10
2.5 Electrical Connections 10
3.0 Temperature Controller 12
4.0 2132 Over-Temperature Controller Description (if fitted) 13
4.1 Description 13
4.2 Operation 13
4.2.1 Controls 13
4.2.2 Operation 14
4.2.3 Over-Temperature Operation 14
4.2.4 Over-Temperature Alarm 14
4.2.5 Resetting the Over-Temperature Alarm 14
4.2.6 Sensor Break 14
4.3 Audible Alarm 15
4.4 Navigation Diagram 15
5.0 Operation 16
5.1 Operating Cycle 16
5.2 General Operating Advice 16
5.3 Operator Safety 17
5.4 Tube Life 17
5.5 Pressure 17
6.0 Maintenance 19
6.1 General Maintenance 19
6.1.1 Cleaning 19
6.2 Calibration 19
6.3 After-Sales Service 19
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6.4 Recommended Spare Parts and Spare Parts Kit 19
6.5 Power Adjustment 20
6.6 Element Ageing 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 Element Fitting and Replacement 23
7.7 Fuse 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
9.2 WA-11-31 28
10.0 Fuses and Power Settings 29
10.1 Fuses 29
10.2 Power Settings 29
User Power Setting Adjustments 30
11.0 Specifications 31
11.1 Environment 31
3

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.
4

Caution – Double Pole/Neutral Fusing
5
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.
6

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.
If the product is supplied with a work tube then the holes at the end of the product
chamber should be supplied at the correct size. Carefully line up the tube and ease it
through the chamber.
For a tube of customer supply, ensure that there is approximately 1 mm free play at
each end; if the tube is too tight, it may crack when heated. Increase the diameter of
the hole by rotating the tube, which is abrasive. Remove loose powdered ceramic fibre
with a vacuum cleaner and see section 7.0.
Contact Carbolite Gero if the holes in the product chamber are too large.
Ensure that the tube is centrally placed and reaches to or through the product end
covers, so that there is no access to exposed electrical connections.
7
2.0 Installation

2.0 Installation
2.3 Tube Fitting
Vertical Mode. The product (if a tube is also supplied) has a plate or clip to retain the
tube in position. See fig.1.
Key
A End guard
B Plate
C Standard tube
D Long tube
E Strap
F Ring clip
Fig 1 - Vertical Tube Retention
Key
A Furnace body
B Tube
C Insulating plug
D End guard
E Stem
Fig 2 - Insulating End Plug
Fit any accessories supplied. For optimum temperature uniformity, ceramic insulation
plugs or radiation shields should be placed in the tube ends as shown in fig.2. The ends
of the insulation plugs or radiation shields should not protrude outside of the work tube.
NOTE: Insulation plugs or Radiation shields are strongly recommended
for this product. Contact Carbolite Gero or Carbolite Gero Service for
further information.
8

Expanded View of "Twin Clamp" End Seals:
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 (under-
neath clamp)
F Tube
Fig 3 'Twin Clamp' End Seal
For assembly details refer to separate work tube and end seal manual.
If stainless steel end 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 end plate.
When stainless steel end seals are fitted in the vertical mode, a hook and eye, on the
end of the plate holds the upper insulating plug or radiation shield assembly.
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 the fittings in such a way
that longitudinal expansion of the tube is allowed.
If a metal work tube is being used in the product, ensure that it is earthed (grounded).
There can be leakage of current through ceramic insulation at high temperatures.
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2.0 Installation

2.0 Installation
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.
2.4 Heating Elements
The silicon carbide elements are VERY FRAGILE and are packed separately. Fit them
accordingly to the instructions in section 7.0.
2.5 Electrical Connections
Connection by a qualified electrician is recommended.
All models covered by this manual may be ordered for single phase A.C. supply, which
may be Live to Neutral non-reversible, Live to Neutral 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. 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).
10

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:
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)
Technical Notes
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.
11
2.0 Installation

3.0 Temperature Controller
3.0 Temperature Controller
If this product is fitted with a temperature controller, instructions are provided
separately.
12

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.
13
4.0 2132 Over-Temperature

4.0 2132 Over-Temperature
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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4.3 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.
15
4.0 2132 Over-Temperature

5.0 Operation
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 controller. The controller
illuminates 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.
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.
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.
16

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. 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.
5.5 Pressure
Work tubes are not able to accept high internal pressure. When gas seals or similar
fittings are in use, the gas pressure should be restricted to a maximum of 0.2 bar (3
psi). 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.
A suitably regulated gas supply should always be used.
17
5.0 Operation

5.0 Operation
It is recommended that a pressure relief system should be used to avoid an over
pressurisation of the work tube.
Please 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.
18

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.
6.1.1 Cleaning
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.
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.
6.2 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.
6.3 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.
6.4 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.
Please consult Carbolite Gero's Sales Department for details of recommended spare
parts.
19
6.0 Maintenance

6.0 Maintenance
6.5 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.
A table of standard power limits is supplied with new products, it is given in section 10.0
6.6 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.
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.
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 10.0.
20