VERDER CARBOLITE GERO CWF-BAL 11/21 Manual

Installation, Operation and Maintenance Instructions
1100°C Chamber Furnace - CWF-BAL Model: 21 Litres
No Controller
CWF-BAL 11/21 + No Controller
MEN-CWF-BAL-1121-005_NOCTRL (01-08-2019)

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 5
2.1 Unpacking and Handling 5
2.2 Siting and Setting Up 5
2.3 Chimney 6
2.4 Electrical Connections 7
2.5 Balance and Weighing Platform 9
3.0 Temperature Controller 11
4.0 2132 Over-Temperature Controller Description (if fitted) 12
4.1 Description 12
4.2 Operation 12
4.2.1 Controls 12
4.2.2 Operation 13
4.2.3 Over-Temperature Operation 13
4.2.4 Over-Temperature Alarm 13
4.2.5 Resetting the Over-Temperature Alarm 13
4.2.6 Sensor Break 13
4.3 Audible Alarm 14
4.4 Navigation Diagram 14
5.0 Operation 15
5.1 Operating Cycle 15
5.2 General Operating Notes 15
5.3 Use of Probes 16
5.4 Atmospheres 16
5.5 Operator Safety 16
5.6 Power Adjustment 17
6.0 Maintenance 18
6.1 General Maintenance 18
6.2 Maintenance Schedule 18
6.2.1 Cleaning 20
2

6.2.2 Safety Switch 20
6.3 Calibration 20
6.4 After-Sales Service 21
6.5 Recommended Spare Parts and Spare Parts Kit 21
7.0 Repairs and Replacements 22
7.1 Safety Warning - Disconnection from Power Supply 22
7.2 Safety Warning - Refractory Fibre Insulation 22
7.3 Temperature Controller Replacement 22
7.4 Solid-State Relay Replacement 23
7.5 Thermocouple Replacement 23
7.6 Panel Element Replacement 24
7.7 Door Plug Replacement 26
7.8 Fuse Replacement 26
8.0 Fault Analysis 28
A. Furnace Does Not Heat Up 28
B. Product Overheats 29
9.0 Wiring Diagrams 30
9.1 WA-U3-30 31
9.2 WA-U3-31 33
10.0 Fuses and Power Settings 35
10.1 Fuses 35
10.2 Power Settings 35
11.0 Specifications 36
11.1 Environment 36
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.
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.
Caution – Double Pole/Neutral Fusing
4

2.0 Installation
2.1 Unpacking and Handling
When unpacking and handling the product, always lift it by its base. Do not use the door
or any other projecting cover or component to support the equipment when moving it.
Use two or more people to carry the product where possible.
Carefully remove any packing material from inside and around the product before use.
Avoid damaging the surrounding insulation when removing packing materials.
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.
5
2.0 Installation

2.0 Installation
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.
2.3 Chimney
The chimney is a length of tubing. If it is supplied unfitted, then fit it through the hole in
the top of the case.
If the product is to be used to heat substances that emit fumes, a fume extraction duct
of approximately 75 mm - 150 mm inlet diameter may be placed directly above the
chimney outlet.
Do not make a sealed connection to the product chimney as this causes excessive
airflow through the chamber and results in poor temperature uniformity.
6

Key
A Duct (75mm-150mm diameter)
B Ambient air is drawn into duct
C Chimney
D 25mm vertical gap between chimney and duct
2.4 Electrical Connections
Connection by a qualified electrician is recommended.
The product covered by this manual normally requires a single phase A.C. supply, which
may be Live to Neutral non-reversible, Live to Neutral reversible or Live to Live. Some
models may be ordered for 3-phase use, which may be star or delta.
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).
7
2.0 Installation

2.0 Installation
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:
3-phase L1 Black to phase 1
L2 Black to phase 2
L3 Black to phase 3
N Light Blue to neutral (except delta)
PE Green/ Yellow to earth (ground)
DO NOT connect a product ordered for three phase use to a single
phase supply or to the wrong type of three phase supply.
8

2.5 Balance and Weighing Platform
1. Assemble the balance unit as shown below:
2. Ensure that the furnace is on a stable, level surface.
3. Place the balance on the support plate below the furnace chamber, ensuring the
front legs are located in the slots on the support plate.
4. Level the balance as detailed in the balance manufacturer’s instruction manual.
5. Open the furnace door.
6. One by one, insert the 3 ceramic tubes through the holes in the hearth, and locate
them over the three corresponding placement guides on the top of the balance.
Note: Due to the secure fit, you may need to twist the tubes down the guides in
order for them to make full contact with the weighing platform.
7. If required, loosen the bolts securing the bottom support plate, and adjust pos-
itioning to move the balance.
9
2.0 Installation

2.0 Installation
8. Carefully position the Silicon Carbide weighing platform onto the top of the ceramic
tubes.
9. Connect the DC power lead and RS-232 plug at the rear of the balance.
10. Before turning on the power supply, connect the earth cable to the earthing bolt on
the support plate.
Important Note: The balance will not stabilise if the ceramic tubes touch the sides of
the holes in the hearth.
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 2132 Over-Temperature
4.0 2132 Over-Temperature Controller Description (if
fitted)
4.1 Description
Key
A Alarm Light
B Page
C Scroll
D Down
E Up
F Display
This over-temperature controller is fitted and supplied ready to use by Carbolite Gero.
It is a digital instrument with a latching alarm, requiring no additional panel controls.
The controller features easy setting of over-temperature setpoint and reading of current
temperature by the over-temperature sensor.
4.2 Operation
4.2.1 Controls
Most Carbolite Gero products are fitted with an instrument switch which cuts off power
to the controller and other parts of the control circuit.
To operate the controller, power must be supplied to the product and the instrument
switch must be on. If a time switch is included in the product circuit, this must be in the
'ON' position.
When an over-temperature condition occurs, the controller cuts the power to a
contactor, which in turn cuts power to the heating elements. Power is not restored until
the controller is 'reset'.
Some components will operate after the over-temperature feature isolates the power
supply e.g. cooling fans will continue to operate, provided that there is a power supply
to the product. In some cases the product may not do so, if other options (such as a
door switch) are fitted.
12

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.
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.
13
4.0 2132 Over-Temperature

4.0 2132 Over-Temperature
4.3 Audible Alarm
If an audible alarm is supplied for use with the over-temperature controller, it is
normally configured to sound on over-temperature condition and to stop sounding when
the alarm is acknowledged as given in section 4.2.
Note: the alarm may sound during controller start-up.
4.4 Navigation Diagram
HL Home List Page Key Black = Progress
OTSP Over-Temperature
Setpoint Scroll Key
Dashed = Through to
other options
AL Access List For factory access to list and parameters not
available to the operator.
14

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 controllers. The controllers
illuminate and go 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 turn the product off, set the instrument switch to its off position. The controller
display will go blank. If the product is to be left unattended, isolate it from the electrical
supply.
5.2 General Operating Notes
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.
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 elements. However, if a large object is placed in the
chamber it may record the average temperature of the object and the elements, this
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, or heat using a slowly controlled ramp rate. For more information refer to
the controller instructions.
When heating materials that produce smoke or fumes, the chimney must be correctly
fitted and unobstructed. If not, soot will accumulate in the chamber and could possibly
cause an electrical breakdown of the heating element. If the furnace is used to heat
materials that emit smoke or fumes, regularly heat it up to maximum temperature for
one hour with the chamber empty to burn away the soot.
15
5.0 Operation

5.0 Operation
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 the Carbolite Gero technical department.
5.3 Use of Probes
Any metal object used to probe into the product chamber while the
product is connected to the electrical supply must be earthed. This
applies in particular to metal sheathed thermocouples, where the
sheaths must be earthed. The refractory material of the chamber lining
becomes partly conductive 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.
5.4 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.
The chamber is not gas tight, the gas usage may be high and the chamber is always
likely to contain some air. Residual oxygen of approximately 1% to 2% is to be
expected.
5.5 Operator Safety
This product incorporates a safety switch which interrupts the heating
element circuit when the furnace is opened. This prevents the operator
touching a live heating element and also prevents the product from
heating up if the furnace is left open. The operation of this switch should
be checked periodically.
Depending on use, the surfaces in the working chamber and the
chamber load may still be very hot after the appliance is switched off.
Touching these surfaces may cause burns. Use suitable personal
protective equipment or wait until the appliance cools down to ambient
temperature.
Before removing a hot object from the product, make sure there is a safe place to put it
down. If necessary use tongs, face masks and heat resistant gloves. Heat resistant
clothing and face protection can guard against the effects of radiated heat when the
furnace is open.
When the product is opened during operation there is considerable radiated heat. Do
not keep any flammable objects near the product, nor objects which could be damaged
by radiated heat.
16

5.6 Power Adjustment
The product control system incorporates electronic power limiting. Depending on the
model and the destination country the power limit maybe set to 100% or a lower figure.
Where appropriate the power limit parameter OP.Hi is accessible to the operator, but it
should not generally be altered.
See section 10.0 for details of the power limit settings. DO NOT adjust the power to a
level higher than the design level states; this may cause a fuse to blow and could
damage the heating elements.
The power limit may be set to a lower limit if the product is to be used at a low
temperature only: this may give better control stability. It may be set to zero to permit
demonstration of the controls without the heating elements taking power; to resume
heating reset it to its standard value.
17
5.0 Operation

6.0 Maintenance
6.0 Maintenance
6.1 General Maintenance
Preventive rather than reactive maintenance is recommended. The type and frequency
depends on the product use; the following are recommended.
6.2 Maintenance Schedule
CUSTOMER
QUALIFIED PERSONNEL
DANGER! ELECTRIC SHOCK. Risk of fatal injury. Only electrically
qualified personnel should attempt these maintenance procedures.
Maintenance
Procedure Method
Frequency
Daily Weekly Monthly Bi-
Annually Annually
Safety
Safety Switch Function
Set a safe temperature above ambient, and
open the door to see if the heater light goes
out
Safety Switch Function Electrical measurement
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
Door Plug Visual inspection, checking the seal and
whether it is free of damage
Door Plug Replacement where necessary
Chimney / Extraction Check and clean if necessary
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, frequency
dependent on the standard required
18

Operational Check Check that all functions are working normally
Operational Check Thorough inspection and report incor-
porating a test of all functions
Performance
Element Circuit Electrical measurement
Power Consumption Measure the current drawn on each phase /
circuit
Hearth Visual check for fit and damage
Cooling Fans (if fitted) Check whether the cooling fans are working
19
6.0 Maintenance

6.0 Maintenance
6.2.1 Cleaning
Soot deposits may form inside the furnace, depending on the process. At appropriate
intervals remove these by heating as indicated in the General Operation Notes.
The product's outer surface may be cleaned with a damp cloth. Do not
allow water to enter the interior of the case or chamber. Do not clean
with organic solvents.
6.2.2 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.
6.3 Calibration
After prolonged use, the controller and/or thermocouple may require recalibration. This
is important for processes that require accurate temperature readings or for those that
use the product close to its maximum temperature. A quick check using an independent
20