Bibby Sterilin CARBOLITE CSF Series Guide

Installation, Operation &
Maintenance Instructions
1100°C - 1200°C Chamber Furnaces
types CSF, BOF & RHF
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.
CONTENTS
Section page
1.0 Introduction 2
2.0 Installation 2
3.0 Operation 2
4.0 Maintenance 4
5.0 Repairs & Replacements 5
6.0 Fault Analysis 8
7.0 Circuit Diagrams 10
8.0 Fuses 11
9.0 S
p
ecifications 12
Manuals are supplied separately for the furnace controller
(and overtemperature controller when fitted).
Please read the controller manuals before operating the furnace.
1.0
MF49

CSF, BOF, RHF
INTRODUCTION
This is “retro” manual, made out to cover the range of 1100-1200°C chamber furnaces, types CSF,
BOF and RHF, made over a period from 1988-1995. The manual does not document detailed
changes over this period.
The controller manuals are not included – manuals or basic instructions are available separately.
In other respects there is some additional material in this manual that was not present in the
original manuals issued with the furnaces.
2.0 INSTALLATION
2.1 Unpacking & Handling
When unpacking or moving the furnace always lift it by its base. Never lift it by the door. Use two
people to carry the furnace where possible.
Remove any packing material from the door gear and furnace chamber before use.
2.2 Siting & Setting Up
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.
If the chimney is supplied unfitted, then fit it into the hole in the top of the furnace case.
If the furnace is to be used to heat substances which emit fumes, then a fume extraction duct of
about 150mm inlet diameter may be placed directly above the chimney outlet. Do not make a
sealed connection to the furnace chimney as this causes excessive airflow through the chamber
and results in poor temperature uniformity.
2.3 Electrical Connections
Connection by a qualified electrician is recommended
All furnaces covered by this manual are for single phase A.C. supply. 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 8.0 of this manual.
Furnace with supply cable: either wire directly to an isolator or fit with a line plug.
Furnace without supply cable: connect to a fused and isolated supply.
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).
3.0
2 MF49

CSF, BOF, RHF
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 appropriate supplementary manual. If cascade
control is fitted, see the supplementary manual MS07.
3.1 Operating Cycle
The furnace is fitted with a Supply light and an Instrument switch. The light is on whenever the
furnace is connected to the supply. The switch cuts off power to the control circuit.
Connect the furnace to the electrical supply. The Supply light should glow.
Operate the instrument switch to activate the temperature controller. The controller becomes
illuminated and goes through a short test cycle.
Close the furnace door and adjust the temperature controller – 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.
Unless a time switch is fitted and is off, the furnace starts to heat up. The Heat light(s) glow
steadily at first and then flash as the furnace approaches the desired temperature or a program
setpoint.
Overtemperature option only. If the overtemperature trip operates then an indicator in the
overtemperature controller flashes, and the heating elements are isolated. Find and correct the
cause before resetting the overtemperature controller according to the instructions supplied.
To switch the furnace off, set the Instrument switch off. If the furnace is to be left off, isolate it the
electrical supply.
3.2 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.
When heating large objects, in particular poor conductors, avoid shielding the thermocouple from
the heating elements. The thermocouple is intended to sense the temperature near the heating
element, but if a large object is placed in the chamber it may record the average temperature of the
object and the elements, which can lead to overheating of the elements. Allow large objects to
gain heat at a lower temperature and then reset the controller to a temperature close to the desired
maximum.
When heating materials which produce smoke or fumes, the chimney must be correctly fitted and
unobstructed. Otherwise, soot accumulates in the chamber and could possibly cause an electrical
breakdown of the heating element. If the furnace is used to heat materials which emit smoke or
fumes, regularly heat it up to maximum temperature for one hour without load to burn away the
soot.
Materials such as case hardening compounds and other reactive salts may penetrate the furnace
chamber lining and attack the wire elements, causing premature failure. Use of a hearth tile may
be advisable: please consult our technical department.
3.3 Use of Probes
Any metal object used to probe into the furnace chamber while the furnace is
connected to the supply must be earthed (grounded). This applies in particular to
metal sheathed thermocouples, where the sheaths must be earthed. The refractory
material of the chamber lining becomes partly conducting at high temperatures, and
the electric potential inside the chamber can be at any value between zero and the
supply voltage. Unearthed probes can cause serious electric shock.
MF49 3

CSF, BOF, RHF
3.4 Atmospheres
When an optional gas inlet is fitted there is a label near the inlet saying "INERT GAS ONLY". In
practice inert or oxidising gases may be used, but not combustible or toxic gases. Chamber
furnaces are not gas tight, so it should be understood that gas usage may be high, and that the
chamber is likely always to contain some air. Residual oxygen levels of 1% are to be expected.
If a metal retort is supplied with this furnace, please see the supplementary manual MS05.
3.5 Operator Safety
The furnace incorporates a safety switch which interrupts the heating element circuit when the
door is opened. This prevents the user touching a live heating element, but also prevents the
furnace from heating up if the door is left open.
Avoid burns. Carbolite can supply tongs, face masks, and heat resistant gloves. Before you
remove a hot object from the furnace make sure you have a safe place to put it down.
4.0 MAINTENANCE
4.1 General Maintenance
No routine maintenance is required other than removal of soot deposits mentioned in 3.2 and the
occasional replacement of consumable items.
The furnace 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.
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 (Thermal 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 Thermal 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, one door insulation piece, and one element or set of elements.
For the RHF models, the element is supplied in its metal housing or insulation box; for the CSF &
BOF models, the two side elements are supplied together with the hearth. Indvidual spares are also
available.
When ordering spares please quote the model details as requested above.
5.0
4 MF49

CSF, BOF, RHF
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
This furnace contains refractory fibres in its thermal insulation. These materials
may be in the form of fibre blanket or felt, vacuum formed board or shapes,
mineral wool slab or loose fill fibre.
Normal use of the furnace 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, we strongly recommend that safety
precautions are taken whenever the materials are handled.
Exposure to dust from fibre which has been used at high temperatures may cause
respiratory disease.
When handling fibre always use an approved mask, eye protection, gloves and long
sleeved clothing.
Avoid breaking up waste material. Dispose of waste fibre 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 Ceramic Fibre
Industry Association Bulletin No. 11 and the UK Health and Safety Executive Guidance Note
EH46.
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
CAL 8000 or 9000 Series
Disconnect the furnace from the mains supply and remove the furnace rear panel. Make a note of
the wire connections to the back of the instrument, and disconnect them.
Remove the plastic clamp around the instrument by pushing the tabs in sideways. Take the
instrument out of the panel from the front.
Reverse the above procedure to install a new instrument.
Eurotherm 103 - Open the flap and withdraw the controller by pulling outwards.
Eurotherm 90 series - Pinch the ribbed areas at the top and bottom of the front surround and pull
outwards.
Eurotherm 800 series - Undo the screw located behind the lower flap and withdraw the controller.
Eurotherm 900 series - If the instrument is fitted in a recess, grip firmly and withdraw. If the top
and bottom of the instrument are accessible, pinch the top and bottom and withdraw.
5.4 Solid-state Relay Replacement
Disconnect the furnace from the supply and remove the furnace back panel.
Make a note 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.
MF49 5

CSF, BOF, RHF
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.
5.5 Thermocouple Replacement
Disconnect the furnace from the supply, and remove the furnace back panel.
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) positive (type R)
White green orange
Disconnect the thermocouple from its terminal block.
Release the screw which secures the thermocouple sheath., withdraw the sheath, and shake out
any fragments of thermocouple.
Re-assemble with a new thermocouple observing the colour coding, ensuring that the
thermocouple is not twisted as it is being inserted.
5.6 Panel Element Replacement (CSF & BOF)
See section 5.2 - wearing a face mask is recommended.
The chambers have two side-mounted refractory panels in which coiled heating elements are
inserted, and one unheated hearth slab.
Disconnect the furnace from the supply and remove the furnace back panel.
Make a written plan showing the element connections. It is important to make this plan for each
individual furnace.
Disconnect all the element wire tails and thermocouple cables from their terminal blocks.
Straighten all the element tails. Note that these become brittle with use.
Open the furnace door and slide out the faulty element(s). Pushing on the tails may sometimes
help to start the slab moving. If two elements have fused together both will have to be replaced.
Slide in the new element(s). Guide the tails through the existing holes in the insulation and re-
connect the element terminal blocks.
As necessary, shorten the element tails by clipping to length. Remake all the element connections
according to the individual plan.
Refit the back panel and run the furnace for 30 minutes at 800°C without interruption to ensure
complete burn-off of any organic binders. Some smoke may be observed during this process,
which should be carried out in a well ventilated area.
Check that the furnace is controlling properly to rule out the possibility that previous element
failed because of a fault elsewhere in the control circuit.
Connections: as shown – but remember to check against your own plan
L
220-240V 110-120V
L N
N
6 MF49

CSF, BOF, RHF
5.7 RHF Element Replacement
See section 5.2- wearing a face mask is recommended.
Elements supplied for these models may not have the original black interior surface. They are just
as good as the originals.
The special heating elements form the chamber sides, back and roof in a single `U' shaped module.
The element is very fragile, so spare elements are supplied complete in a "Brick Box" to avoid
damage. The hard crust-like surface of the element is easily broken by firm finger pressure: try
not to touch it (see also 6 below - always lift the brickbox by its metal casing).
Disconnect the furnace from the mains supply.
Remove the furnace case back panel.
Disconnect the 2 element power leads and the thermocouple connections. Remove the
thermocouple and support tube.
Remove the back panel of the control box and using a socket undo the two bolts that hold in the
insulation box. These are located in the roof of the control box. Two more bolts are to be found
below the front shelf of the furnace.
Using the new brick box repeat the instructions above in reverse order. Do not support the
element by putting your hand inside the chamber - the element is fragile.
After replacing the back panel and reconnecting the mains supply, run the furnace for a minimum
of 30 minutes at 800°C with the chimney open, to ensure complete burn-off of organic binders.
Do not interrupt this initial heat-up cycle. Some smoke may be observed during this process.
Check that the furnace is controlling properly to rule out the possibility that previous element
failed because of a fault elsewhere in the control circuit.
5.8 Door Plug Replacement (early models)
If the door plug is held in position by spikes and adhesive, please contact Carbolite’ service
department.
5.9 Door Plug Replacement (later models)
Lift the furnace door to the open position and remove the door cover from the plug carrier
assembly. Take care: removal of the carrier reduces the weight of the door and affects the
counterbalance effect.
Remove the old door plug by sliding it upwards out of its carrier.
Slide the new plug into the carrier assembly making sure that the plug is the correct way up.
Refit the door cover.
When first heating the furnace after a replacement, ensure that the ventilation is good: emission of
some fumes may be expected.
MF49 7

CSF, BOF, RHF
5.10 Fuse Replacement
Fuses are marked on the circuit diagram (section 7.0) with type codes, e.g. F1, F2. A list of the
correct fuses is given in section 8.0. 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.
The fuses are near the cable entry point, and access is by removal of the back panel.
6.0
8 MF49

CSF, BOF, RHF
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
!The SUPPLY
light is ON
!The controller may be
faulty or not receiving a
supply due to a faulty
switch or a wiring fault
!The SUPPLY
light is OFF
!Check the supply fuses and
any fuses in the furnace
control compartment
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
7.0
MF49 9

CSF, BOF, RHF
CIRCUIT DIAGRAMS
There are some minor variations of the diagram below.
Safety switches A are door switches that apply when there is no contactor present.
Safety switch B is a door switch that applies where there is a contactor present. A contactor is
present if overtemperature control is fitted, or if the current rating exceeds 25A.
7.1 Single Phase
Supply ligh
t
Instrument Switch
coil
thermocou
p
le
temperature
controller
overtemp.
controller
safety
switch B
thermocou
p
le
i
f
f
itted
L
N
F2
F1
PE
contacto
r
if fitted
e
l
e
m
e
n
t
(s)
hea
t
on
SSR
safety
switches A
Filter
(
if fitted
)
8.0
10 MF49

CSF, BOF, RHF
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
Customer
fuses
Required if no supply cable fitted.
Recommended if cable fitted.
See rating label for amperage;
see table below for fuse rating.
Model Phases Volts Supply Fuse
Rating
Volts Supply Fuse
Rating
CSF -/3 1-phase 220-240 10A 110-120 15-16A
CSF -/3 1-phase 208 10A 100 16A
CSF -/7 1-phase 220-240 10A 110 / 120 20
CSF -/7 1-phase 208 13A 100 15A
CSF -/13 1-phase 220-240 13A 110 / 120 25A
CSF -/13 1-phase 208 15-16A 100 30-32A
RHF -/3 1-phase 220-240 10A
RHF -/7 1-phase 220-240 13A
RHF -/13 1-phase 220-240 25A
BOF range - same as CSF
9.0
MF49 11

SPECIFICATIONS
Carbolite reserves the right to change specifications without notice.
9.1 Models Covered by this Manual
MODEL Max.
Temp.
Max.
Power
Chamber Size (mm) type of heating
(°C) (kW) HWD
Chamber furnaces heated by resistance wire inserted in refractory formers.
CSF 11/3 1100°C 1.7 145 135 175 slabs (2)
CSF 11/7 1100°C 2.4 175 170 245 slabs (2)
CSF 11/13 1100°C 3.0 210 205 300 slabs (2)
CSF 12/3 1200°C 1.7 145 135 175 slabs (2)
CSF 12/7 1200°C 2.4 175 170 245 slabs (2)
CSF 12/13 1200°C 3.0 210 205 300 slabs (2)
Burn-off versions of the above.
BOF 11/13 1100°C 3.0 210 205 300 slabs (2)
BOF 12/13 1200°C 3.0 210 205 300 slabs (2)
Chamber furnaces heated by resistance wire embedded in low thermal mass
insulation.
RHF 12/3 1200°C 2.1 140 150 165 vac-formed
RHF 12/7 1200°C 3.0 165 190 235 vac-formed
RHF 12/13 1200°C 5.3 200 300 290 vac-formed
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
Copyright © 2004 Bibby Sterilin Limited trading as Carbolite
Carbolite, Parsons Lane, Hope,
Hope Valley, S33 6RB, England.
Telephone: [phone]
Int: [phone]
Facsimile: [phone]
Int: [phone]
E-mail: [email protected]
For preventive maintenance, repair and calibration of all Furnace
and Oven products, please contact:
Thermal Engineering Services
Telephone: UK: 0845 3308035 Int: [phone]
Fax: UK: 0845 3308036 Int: [phone]
Email: [email protected]
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
p
roducts
p
lease contact us at the address below
,
or ask
y
our nearest stockist.
MF49-1.01 30/3/04 CSF retro