VERDER CARBOLITE GERO HZS-2G 12/425 Manual

Installation, Operation and Maintenance Instructions
1200°C 2-Gradient Split Tube Furnace - HZS-2G Model: 425mm
No Controller
HZS-2G 12/425 + No Controller
MEN-HZS2G12425-11_NOCTRL (02-08-2019)

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 Electrical Connections 9
3.0 Temperature Controller 11
4.0 Operation 12
4.1 Operating Cycle 12
4.2 General Operating Advice 12
4.3 Operator Safety 13
4.4 Tube Life 13
4.5 Pressure 13
4.6 Power Adjustment 14
4.7 Running at Low Temperatures 14
5.0 Maintenance 15
5.1 General Maintenance 15
5.2 Maintenance Schedule 15
5.2.1 Cleaning 17
5.2.2 Safety Switch 17
5.3 Calibration 17
5.4 After-Sales Service 18
5.5 Recommended Spare Parts and Spare Parts Kit 18
6.0 Repairs and Replacements 19
6.1 Safety Warning - Disconnection from Power Supply 19
6.2 Safety Warning - Refractory Fibre Insulation 19
6.3 Temperature Controller Replacement 19
6.4 Solid-state Relay Replacement 20
6.5 Thermocouple Replacement 20
6.6 Fuse Replacement 20
6.7 Element Replacement 21
2

7.0 Fault Analysis 22
A. Furnace Does Not Heat Up 22
B. Product Overheats 23
8.0 Wiring Diagrams 24
8.1 01890-5001 24
9.0 Fuses and Power Settings 25
9.1 Fuses 25
9.2 Power Settings 25
User Power Setting Adjustments 26
10.0 Specifications 27
10.1 Environment 27
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 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.
6

Ensure that the product is placed in such a way that it can be quickly switched off or
disconnected from the electrical supply.
If the product is supplied with a work tube or any accessories fit these into position.
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.
If a metal work tube is being used in the product, ensure that it is earthed for operator
safety.
7
2.0 Installation

2.0 Installation
Fig 1 - Insulating Plug
(standard length tube) Key
A Tube
B Insulating Plug
C Stem
Fig 2 - Insulating Plug
(long work tube)
8

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.
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 Electrical Connections
Connection by a qualified electrician is recommended.
9
2.0 Installation

2.0 Installation
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. 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:
10

3.0 Temperature Controller
If this product is fitted with a temperature controller, instructions are provided
separately.
11
3.0 Temperature Controller

4.0 Operation
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.
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.
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.
12

4.3 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.
4.4 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.
4.5 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.
13
4.0 Operation

4.0 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.
4.6 Power Adjustment
The control system incorporates electronic power limiting. The power limit parameter
OP.Hi is accessible to the operator and can be used to adjust the furnace to the actual
supply voltage.
The models covered by this manual are designed for use over the range of voltages 200
V - 250 V (or, if ordered, 100 V - 125 V), and the power limit parameter is set
accordingly. These models may be adjusted to a different voltage within the range: the
power limit should be reset to match OP.Hi, see 9.0
Refer to section 3.0 for power adjustment instructions.
4.7 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.
14

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 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
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 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-
rect positioning
15
5.0 Maintenance

5.0 Maintenance
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
16

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.
5.2.2 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.
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
17
5.0 Maintenance

5.0 Maintenance
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 of each type of thermocouple, one solid state relay and two
heating elements.
When ordering spare parts please quote the model details as requested above.
18

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.
19
6.0 Repairs and Replacements

6.0 Repairs and Replacements
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
For vertical models it may be necessary to dismount the furnace from its stand and
remove the terminal cover.
Disconnect the product from the power supply. Remove terminal cover to gain
access to the thermocouple connections. Make a note of the thermocouple
connections.
Thermocouple cable colour codings are:
thermocouple leg colour
positive (type N) pink
negative white
Disconnect the thermocouple from its terminal block.
Carefully withdraw the thermocouple from the product and remove any broken bits of
thermocouple.
Bend the new thermocouple carefully to match the shape of the original (working from
the terminal end). Should the length differ from that of the original this is usually not
important provided that the thermocouple tip is within a work tube diameter's distance
from the furnace centre.
Insert the new thermocouple into position, restoring any removed porcelain spacers and
ensuring correct polarity.
Re-assemble the furnace.
6.6 Fuse Replacement
Fuses are marked on the wiring diagram with type codes, e.g. F1, F2. For more
information on fuses refer to section 9.0.
Depending on model and voltage, the different fuse types may or may not be fitted.
If any fuse has failed, it is advisable for an electrician to check the internal circuits.
Replace any failed fuses with the correct type. For safety reasons do not fit larger
capacity fuses without first consulting Carbolite Gero.
20