Carbolite HTR 11/75 Guide

MF30 –3.06
Installation, Operation &
Maintenance Instructions
1100°C Rotary Reactors
HTR 11/75 & HTR 11/150
This manual is for the guidance of operators of the above Carbolite products
and should be read before the furnace is connected to the electricity supply.
Manuals are supplied separately for the furnace controller
(and overtemperature controller when fitted).
Please read the controller manuals before operating the furnace.
CONTENTS
Section page
1.0 Symbols & Warnings 2
2.0 Installation 3
3.0 Operation 5
4.0 Maintenance 7
5.0 Repairs & Replacements 8
6.0 Fault Analysis 10
7.0 Circuit Diagrams 11
8.0 Fuses & Power Settings 14
9.0 Specifications 16

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2 MF30 –3.07
1.0 SYMBOLS &WARNINGS
1.1 Switches and Lights
1.2 Warning Symbols
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
DANGER of electrical shock–read any warning printed by this symbol.
DANGER –hot surface. Read any warning printed by this symbol.
WARNING: all surfaces of a furnace may be hot.
DANGER –read any warning printed by this symbol.

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MF30 –3.07 3
2.0 INSTALLATION
2.1 Unpacking & Handling
When unpacking or moving the furnace lift it by both ends of its base. Never lift it by any protruding parts
or by the lid. Preferably, use two people to carry the furnace.
Remove any packing material from around or inside the furnace before use.
NOTE: This product contains Refractory Ceramic Fibre (better described as Alumino Silicate Wool)
for precautions and advice in handling this material see the ‘Repairs and Replacements’ section.
2.2 Siting
Place the furnace in a well ventilated room, away from other sources of heat, and on a surface which is
resistant to accidental spillage of hot materials. Do not mount the furnace on an inflammable surface.
Ensure that there is free space around the furnace. Do not obstruct any of the vents in the control section:
they are needed to keep the controls cool.
Ensure that the furnace is placed in such a way that it can be quickly switched off or disconnected from the
electrical supply - see below.
2.3 Electrical Connections
Connection by a qualified electrician is recommended
The furnace is made for single phase A.C. supply, which may be Live to Neutral non-reversible,
Live to Neutral reversible or Live to Live.
Check the furnace rating label before connection. The supply voltage should agree with the voltage
on the label, and the supply capacity should be sufficient for the amperage on the label.
The supply should be fused at the next size equal to or higher than the amperage on the label. A
table of the most common fuse ratings is also given in section 8.1 of this manual. Where a supply
cable is present there are internal supply fuses; customer fusing is preferred but not essential.
Furnace with supply cable: either wire directly to an isolator or fit with a line plug.
Furnace without supply cable: a permanent connection to a fused and isolated supply should be
made to the internal terminals after temporary removal of the furnace back panel.
Connection by line plug: the plug should be within reach of the operator, and should be quickly
removable.
Connection to isolating switch: this should operate on 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).
CONNECTION DETAILS
supply type
Supply
Terminal label
Cable colour
Live-Neutral
Reversible or Live-Live
1-phase
L
Brown
To live
to either power conductor
N
Blue
To neutral
to the other power conductor
PE
Green/Yellow
To earth (ground)
to earth (ground)
2.4 Gas Supply
The furnace is supplied with a Nitrogen inlet and flowmeter as standard. The gas supply must be
provided with an on/off valve and pressure regulator to a maximum of 4 psi. Connect the gas
supply to the inlet on the left-hand side. The exhaust box on the right-hand side may be connected
to a outlet pipe provided this does not restrict the gas flow. The exhaust incorporates a safety
pressure relief valve set to relieve pressure above 1 psi in case the exhaust becomes blocked.
Do not use toxic gases without taking appropriate precautions. The furnace is not suitable for use
with combustible gases.

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4 MF30 –3.07
2.5 Installing the Vessel
Silica vessel: see section 3.5. Handle the vessel with care.
The drive coupling assembly is fitted to the vessel as indicated in fig. 1, using the special spanner
provided. Slide the components into place, support part 2 firmly with the hand, and tighten part 1
with the spanner. Do not overtighten. The end of the vessel with this assembly fitted becomes the
left-hand end.
Lightly lubricate the drive coupling assembly and the furnace drive wheels, using 300°C grease.
Place the vessel onto the furnace by pushing it into the exhaust box on the right-hand side, and
lowering it onto the right-hand support wheels and the left-hand drive wheels.
Connect the left-hand end coupling according to fig. 2, using hand pressure only.

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MF30 –3.07 5
3.0 OPERATION
The instructions for operating the temperature controller are given in a separate manual.
If the furnace is fitted with a time switch, see also the supplementary manual MS03.
If cascade control is fitted, see the supplementary manual MS07.
3.1 Operating Cycle
The furnace is fitted with an Instrument switch. The switch cuts off power to the controller(s), to
the heating elements (via a contactor), and to the vessel drive motor.
Connect the furnace to the electrical supply.
Operate the instrument switch to activate the temperature controller. The controller becomes
illuminated and goes through a short test cycle. Depending on the lid, the motor setting, and the
overtemperature controller (if fitted), the vessel may start to rotate.
Set the temperature controller to the desired setpoint or program –see the controller manual.
Overtemperature option only. If the overtemperature controller has not yet been set as required, set
it and activate it according to the instructions in the appropriate manual.
The furnace starts to heat up. The Heat light glows steadily at first and then flashes as the furnace
approaches the desired temperature or a program setpoint.
Overtemperature option only. If the overtemperature trip operates then an indicator in the over-
temperature controller flashes, and the heating elements are isolated. Find and correct the cause
before resetting the overtemperature controller according to the instructions supplied.
To turn the furnace off, set the Instrument switch to it’s off position; the controller display will go
blank. If the furnace is to be left off unattended, isolate it the electrical supply.
3.2 Vessel & Gas Supply
Only fill the vessel to a level below the central tube extensions, so that powder cannot work along
the tube during operation.
Do not exceed the following maximum weights of load (applicable to silica glass vessels):
HTR 11/75 - 120 gm HTR 11/150 - 950 gm
The vessel oscillation is controlled by a unit on the front panel, which has an on/off switch and a
rotary dial. The dial sets speeds between 1 and 8 cycles per minute. The vessel rotates in alternate
directions through an angle of 315°.
Set the flowmeter to the desired rate of gas flow.
3.3 General Operating Notes
Heating element life is shortened by use at temperatures close to maximum. Do not leave the
furnace at high temperature when not required. The maximum temperature is shown on the
furnace rating label and on the back page of this manual.
Ensure that the vessel is rotating whenever the furnace is at a high temperature, to prevent sagging.
Do not operate the furnace with toxic gases unless suitable exhaust disposal precautions are in
force.
Lightweight ceramic fibre insulation can be marked by accidental contact. Some fine cracks may
be visible on the surface of the insulation, or may develop in the surface of the chamber due to the
progressive shrinkage of the insulation materials. Cracks are not usually detrimental to the
functioning or the safety of the furnace.

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6 MF30 –3.07
3.4 Operator Safety
The ceramic materials used in furnace manufacture become electrically conductive to some extent
at elevated temperatures. Do not insert conductive tools or items in the chamber without isolating
the elements. If a metal vessel is used, it should be guarded against being touched when the
furnace is on.
The elements are isolated when lid is open or the instrument switch is off. For full safety,
disconnect the furnace from the electrical supply.
Avoid burns. Use appropriate handling equipment, face masks, and heat resistant gloves. Before
you remove a hot vessel from the furnace make sure you have a safe place to put it down. Take
care: the vessel may be hot but look cold.
CAUTION: the furnace is designed for operators who understand their process. DO NOT use the
equipment with dangerous gases or materials without proper safety precautions. This is the
customer’s responsibility: Carbolite can only advise on precautions for specific processes if asked.
3.5 Care of the Vessel (Silica)
The fused silica (“quartz”) vessel is fragile and expensive: at all times take care in handling it.
Always make sure that there is somewhere safe to put it down before moving it.
Fused silica has a high resistance to thermal shock. Nevertheless, avoid sudden temperature
changes. For example: do not allow cold water to splash onto a hot vessel.
3.6 Devitrification and Chemical Attack (Silica)
Fused silica is liable to devitrify at high temperature. This is a recrystallisation process which is
greatly affected by surface conditions and therefore by contaminants in the furnace atmosphere. At
1000°C only a highly contaminated atmosphere has a noticeable effect, but at 1100°C the rate of
devitrification may become significant.
A devitrified vessel eventually fails. Failure is likely to be by cracking after cooling below 300°C.
Impurities such as alkali or alkaline earth ions, which occur in dust and perspiration, should be
avoided. It is advisable to handle the vessel with clean gloves or a dry cloth, and to touch the
central (hot) part as little as possible.
The silica vessel should be cleaned with pure alcohol, and wiped dry with a clean cloth.
The specific substances used by the customer’s process may, of course, be prime causes of
devitrification, as they may attack the vessel inner surface chemically and by abrasion. Carbolite
can advise, or seek external advice, on specific materials, if requested.
The following lists some elements and compounds known to cause devitrification. The list is not
exhaustive.
Severe below 1000°C
Na Fe Co Sn LiCl SnCl3
Severe above 1000°C
Mg Ba Mn Cu Sb MgO BaCO3 NaCl KCl CsCl BaCl2
Less severe
Al As Sn(OH)2Ba(OH)2CaCO3 CaCl2
Not known to cause
devitrification up to
1100°C
Ca B Ti Zr V Nb Ta Cr Mo W Ni Ag Zn Cd Hg C Si
Pb S Se Ir H2O CaO Al2O3SiO2P2O5MoO3 WO3ThO2
RbCl NaBr Kbr NaI KI MgCl2AlCl3
Some substances chemically attack silica. In particular, hydrofluoric acid attacks it at all
temperatures, and phosphoric acid above 150°C. Concentrated alkaline solutions may attack at
high temperatures, while carbon and some metals may cause reduction.

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MF30 –3.07 7
4.0 MAINTENANCE
4.1 General Maintenance
No routine maintenance is required. The outer surfaces may be cleaned with a damp cloth. Do not
allow water to enter the interior of the case, tube or control box. Do not clean with organic
solvents.
Silica vessels should be kept clean - see section 3.5.
4.2 Calibration
After prolonged use the controller and/or thermocouple could require recalibration. This would be
important for processes which require accurate temperature readings or which use the furnace
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 can supply these items.
Depending on the controller, the controller manual may contain calibration instructions.
4.3 After Sales Service
Carbolite’s service division (Carbolite Engineering Services) has a team of Service Engineers
capable of repair, calibration and preventive maintenance of furnace and oven products at our
customers’ premises throughout the world. We also sell spares by mail order. A telephone call or
fax often enables a fault to be diagnosed and the necessary spare part despatched.
Each furnace has its own record card at Carbolite. In all correspondence please quote the serial
number, model type and voltage given on the rating label of the furnace. The serial number and
model type are also given on the front of this booklet when supplied with a furnace.
To contact Carbolite Engineering Services or Carbolite see the back page of this manual.
4.4 Recommended Spares Kits
Carbolite can supply individual spares, 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 comprises one thermocouple,
one sheath, one solid state relay, and one heating element.
When ordering spares please quote the model details as requested above.
4.5 Power Adjustment
The furnace control system incorporates electronic power limiting. Depending on the model this
has a maximum setting related to the supply voltage. The power limit parameter OP.Hi may be
inaccessible to the operator.
Occasionally the power limit is set to zero to permit demonstration of the controls without the
heating elements taking power. In this case the power limit is accessible to the operator and may
safely be reset to its standard value. See section 9.0 for details of power limit settings.

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8 MF30 –3.07
5.0 REPAIRS &REPLACEMENTS
5.1 Safety Warning –Disconnection from Supply
Always ensure that the furnace is disconnected from the supply before repair
work is carried out.
5.2 Safety Warning - Refractory Fibrous Insulation
Insulation made from High Temperature Insulation Wool
Refractory Ceramic Fibre, (better described as Alumino 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, mineral wool slab or loose fill wool.
Whilst there is no evidence of any long term health hazards, we strongly recommend that safety
precautions are taken whenever the materials are handled.
Exposure to fibrous dust may cause respiratory disease.
When handling the material always use an approved respiratory protection equipment
(RPE-i.e. 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 we recommend reference to the European Association
representing the High Temperature Insulation Wool industry (www.ecfia.eu)
We can provide further information on request. Alternatively our service division can quote for
any repairs to be carried out at your premises or ours.
5.3 Temperature Controller Replacement
301. This controller is fitted to the back of the control panel; in many models this can be separated
from the base by removal of two screws.
Before handling the controller: wear an anti-static wrist strap or otherwise avoid any possibility
of damage to the unit by static electricity.
Refer to the detailed instructions supplied with the replacement controller.
2132, 3216, 3508 etc. Ease apart the two lugs at the side; grip the instrument and withdraw it from
its sleeve; push in the replacement.
5.4 Solid-state Relay Replacement
Disconnect the furnace from the supply and remove the back panel from the base.
Make a note of how the wires are connected to the solid state relay, and disconnect them.
Remove the solid state relay from the base panel or aluminium plate.
Replace and reconnect the solid state relay ensuring that the heat-conducting thermal pad is
sandwiched between the relay and the base panel or aluminium plate. Alternatively a thin layer of
white, heat-conducting silicon paste may be applied between the new relay and the plate.
The new solid state relay contains a built-in MOV which protects it from short periods of excess
voltage. If the old relay had a separate disc-shaped "MOV" connected between the high voltage
terminals of the old relay, discard the old MOV.
Replace the removed panel.

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MF30 –3.07 9
5.5 Thermocouple Replacement
Disconnect the furnace from the supply, and remove the back panel. The thermocouple and its
sheath are on the exhaust (right-hand) side.
Make a note of the thermocouple connections. The negative leg of the thermocouple is marked
blue. Compensating cable colour codings are:
negative
positive (type K)
white
green
Disconnect the thermocouple from its terminal block.
Withdraw the thermocouple from its sheath and remove any broken bits of thermocouple.
Insert the new thermocouple into position, restoring any removed porcelain spacers, and ensuring
correct polarity.
Re-assemble the furnace.
5.6 Element Replacement
See section 5.2 - wearing a face mask is recommended.
The element is supplied complete with the surrounding stainless steel half-cylindrical inner
chamber.
Disconnect the furnace from the electrical supply, and remove the back panel. Work with the
furnace lid open, with no vessel in place.
Make a careful note of the colours and positions of all the electrical connections to the inner
cylindrical chamber and thermocouple.
Disconnect the thermocouple and element connections from their terminal blocks.
Remove the thermocouple. It may also be necessary to remove the thermocouple sheath: loosen
the retaining screw and withdraw the sheath.
Supporting the weight of the inner chamber, loosen 4 screws holding brackets to the top plate;
loosen and remove 4 screws holding the chamber to the brackets.
Lift out the inner chamber.
Fit the new chamber by reversing the process. Take care to make all connections to the correct
terminals. Do not overtighten the connectors in porcelain terminal blocks.
Let the furnace heat up at its maximum rate to 900°C without interruption, and then soak for 1
hour. Fumes may be emitted: this should be done in conditions of good ventilation.
Check that the furnace is controlling properly to rule out the possibility that the element failed
because of a fault in the control system.
If you have any problems with this procedure, please contact our service division.

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10 MF30 –3.07
6.0 FAULT ANALYSIS
A.
Furnace Does Not Heat Up
1.
The HEAT light
is ON

The heating
element has failed

Check also that the SSR is working
correctly
2.
The HEAT light
is OFF

The controller
shows a very high
temperature or a
code such as S.br

The thermocouple has broken or has a
wiring fault

The controller
shows a low
temperature

The door switch(es) (if fitted) may be
faulty or need adjustment

The contactor (if fitted) may be faulty

The SSR could be failing to switch on due
to internal failure, faulty logic wiring from
the controller, or faulty controller

There are no lights
glowing on the
controller

Check the supply fuses and any fuses in the
furnace control compartment

The controller may be faulty or not
receiving a supply due to a faulty switch or
a wiring fault
B.
Furnace Overheats
1.
The HEAT light
goes OFF with
the instrument
switch

The controller
shows a very high
temperature

The controller is faulty

The controller
shows a low
temperature

The thermocouple may have been shorted
out or may have been moved out of the
heating chamber

The thermocouple may be mounted the
wrong way round

The controller may be faulty
2.
The HEAT light
does not go off
with the
instrument
switch

The SSR has failed
“ON”

Check for an accidental wiring fault which
could have overloaded the SSR

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MF30 –3.07 11
7.0 CIRCUIT DIAGRAMS
7.1 Rotary Reactor: 208V-240V
Instrument Switch
coil
temperature
controller
thermocouple
overtemp.
controller
thermocouple
SSR
e
l
e
m
e
n
t
(s)
heat
on
F1
F2
N
L
PE
Filter
(if fitted)
contactor
or relay
overtemperature
if fitted
motor
controller
motor
door
switch

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12 MF30 –3.07
7.2 Rotary Reactor: 110-120V
Instrument Switch
coil
temperature
controller
thermocouple
overtemp.
controller
thermocouple
SSR
e
l
e
m
e
n
t
(s)
heat
on
F1
F2
N
L
PE
Filter
(if fitted)
contactor
or relay
overtemperature
if fitted
motor
controller
motor
115V
door
switch
240V
transformer

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MF30 –3.07 13

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14 MF30 –3.07
8.0 FUSES &POWER SETTINGS
8.1 Fuses
F1-F3: Refer to the circuit diagrams.
F1
Internal
supply
fuses
Fitted if supply cable fitted.
Fitted on board to some types of EMC filter.
on-board and up to 16 Amps:
32mm x 6mm type F
other: GEC Safeclip
F2
Auxiliary
circuit
fuses
Fitted on board to some types of EMC filter.
May be omitted up to 25Amp/phase supply
rating.
2 Amps glass type F
On board: 20mm x 5mm
Other: 32mm x 6mm
F3
Heat Light
fuses
May be omitted up to 25 Amp/phase supply
rating.
2 Amps glass type F
32mm x 6mm
Customer
fuses
Required if no supply cable fitted.
Recommended if cable fitted.
See rating label for amperage;
see table below for fuse rating.
Access to internal fuses is by removal of the back panel of the furnace base or control box.
Model
phases
Volts
Supply Fuse
Rating
Volts
Supply Fuse
Rating
HTR 11/75
1-phase
200-240
10A
110-120
16A
HTR 11/150
1-phase
220-240
12.5A
110-120
25A
other models or voltages: check the rating label for details of the supply.

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MF30 –3.07 15
8.2 Power Settings
The following values of the OP.Hi parameter apply.
Do not increase the setting beyond the value in the table: the wiring and the elements are designed
on the basis of the declared settings.
Model Volts:
200V
208V
220V
230V
240V
110V
115V
120V
HTR 11/75
100
100
89
81
75
89
82
75
HTR 11/150 (before year 2001)
100
100
100
100
100
HTR 11/150 (year 2001 on)
100
100
89
81
75

Carbolite, Parsons Lane, Hope,
Hope Valley, S33 6RB, England.
Telephone: [phone]
Fax: [phone]
E-mail: [e-mail]
The products covered in this manual are only a small part of the wide range of
ovens, chamber furnaces and tube furnaces manufactured by Carbolite for
laboratory and industrial use. For further details of our standard or custom built
products please contact us at the address below, or ask your nearest stockist.
Copyright © 2014 Carbolite Limited
For preventive maintenance, repair and calibration of all Furnace
and Oven products, please contact:
Carbolite Engineering Services
Telephone: [phone]
Fax: [phone]
Email: [email protected]
MF30 –3.07 14/08/14
9.0 SPECIFICATIONS
Carbolite reserves the right to change specifications without notice.
9.1 Models Covered by this Manual
MODEL
Max.
Temp.
Max.
Power
Vessel
Capacity
Net
Weight
(approx.)
(°C)
(kW)
(gm)
(kg)
High temperature Rotary Reactor
Heated by resistance wire embedded in ceramic fibre
HTR 11/75
1100°C
1.5
120
53
HTR 11/150
1100°C
2.6
950
100
9.2 Environment
The furnaces contain electrical parts and should be stored and used in indoor conditions as
follows:
temperature:
5°C - 40°C
relative humidity:
maximum 80% up to 31°C decreasing linearly to 50% at 40°C