VERDER CARBOLITE GERO CDHT 450 Manual

Installation, Operation and Maintenance Instructions
200°C Coal Drying Oven - CDHT Model: 450 Litres
No Controller
CDHT 450 + No Controller
MEN-CDHT450-005_NOCTRL (18-10-2021)

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 Electrical Connections 6
3.0 Temperature Controller 8
4.0 Operation 9
4.1 Operating Cycle 9
4.2 Over-Temperature Control (if fitted) 9
4.3 Explosive Vapours 9
4.4 Coal Drying Application 10
5.0 Maintenance 11
5.1 General Maintenance 11
5.2 Maintenance Schedule 11
5.2.1 Cleaning 13
5.3 Calibration 13
5.4 After-Sales Service 13
5.5 Recommended Spare Parts and Spare Parts Kit 13
5.6 Power Adjustment 13
6.0 Repairs and Replacements 15
6.1 Safety Warning - Disconnection from Power Supply 15
6.2 Safety Warning - Refractory Fibre Insulation 15
6.3 Panel Removal 15
6.4 Temperature Controller Replacement 16
6.5 Fuse Replacement 16
6.6 Element Replacement 17
6.7 Thermocouple Replacement 17
6.8 Solid-state Relay Replacement 17
7.0 Fuses and Power Settings 18
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7.1 Fuses 18
7.2 Power Settings 18
8.0 Fault Analysis 19
A. Oven Does Not Heat Up 19
B. Oven Overheats 19
9.0 Wiring Diagrams 20
10.0 Specifications 21
10.1 Environment 21
3

1.0 Symbols and Warnings
1.1 Switches and Lights
Instrument switch: when the instrument switch is operated the
temperature control circuit is energised.
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 or moving the product, always lift by its base; do not use the door or
any other projecting cover or component to support the equipment when moving it.
Use a fork lift or pallet truck to move the product; position the product on a level
surface and use an adequate number of personnel to safely move the product into
position.
Carefully remove any packing material from inside and around the product before use.
Avoid damaging the surrounding insulation when removing packing materials.
Locate the shelves as required.
Some models may be lifted by fitting lifting bolts to captive threads which are fitted in
the top of the case, whilst others may have welded on lifting eyes.
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
Note: This LGP oven is supplied with a floor stand that elevates it approximately 500
mm off the ground.
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

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 Electrical Connections
Connection by a qualified electrician is recommended.
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 electrical supply capacity should be sufficient for the
current on the label.
A table of the most common fuse ratings is also given in section 7.0 towards the back
of this manual. Ensure that the correct fuse is used for the product supplied. When the
mains cable is factory fitted internal fuses are also fitted. Customer fusing is essential.
Product with supply cable: either wire directly to an isolator or fit with a line plug.
6

Product without supply cable: a permanent connection to a fused and isolated supply
should be made to the internal terminals after temporary removal of the product
access panel. The access panel is located at the top of the 'A' models and the right
hand side of the 'B' models.
Connection by line plug: the plug should be within reach of the operator and should be
easy to remove.
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 electrical supply MUST incorporate an earth (ground).
Supply Terminal Label Cable Colour
Supply Types
Live - Neutral Reversible or Live-
Live
1-phase L1 Brown to live
to either power
conductor
(For USA 200-240V,
connect L1)
N / L2 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.
7

3.0 Temperature Controller
If this product is fitted with a temperature controller, instructions are provided
separately.
8

4.0 Operation
4.1 Operating Cycle
The product is fitted with an instrument switch. The switch cuts off power to the
controllers and elements. The circulation fan will operate when the instrument switch is
on. An optional door switch may be fitted. If so, ensure that the door is closed to
operate the fans and heating elements.
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.
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 the product off, turn off the instrument switch. If the product is to be left
unattended, isolate the electricity supply.
DO NOT switch off if the temperature is above 100 °C - damage could be caused to the
fan and motor. Adjust the controller to allow the temperature to fall.
4.2 Over-Temperature Control (if fitted)
The over-temperature controller should typically be set at 15 °C above the main
controller. If an over-temperature condition occurs, check the main controller is
functioning correctly.
An over-temperature condition cuts off power to the heating elements. A light in the
over-temperature controller flashes. To reset this, refer to the over-temperature
control section of this manual.
4.3 Explosive Vapours
Unless your product includes the stoving and curing option, this
model is not suitable for drying or heat treatment applications where
vapours are released that are combustible or which can form
explosive mixtures with air. Carbolite Gero manufactures other
products suitable for these applications.
9

4.4 Coal Drying Application
The CDHT is designed to operate at typically 150°C - 200°C to dry and test coal
samples in accordance with international standards.
The oven has air inlet and outlet vents designed to ensure a constant flow of fresh air
to dry the samples and carry moisture away.
Open the inlet and outlet vents to the minimum amount required to ensure consistent
drying results.
10

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 tem-
perature and check for an over-tem-
perature alarm as detailed in this
manual
Over-Temperature Safety Circuit
(if fitted) Electrical measurement
Door Seal Visual inspection - check for splits or
fraying
Door Seal Replacement
Air Vent 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, fre-
quency dependent on the standard
required
Operational Check Check that all functions are working
normally
Operational Check Thorough inspection and report incor-
porating a test of all functions
11

Performance
Cooling Fans (if fitted) Check whether the cooling fans are
working
Circulating Fan
(if fitted) Visual check to see if it is running
Circulating Fan
(if fitted)
Check bearings and replace if neces-
sary
Element Circuit Electrical measurement
Power Consumption Measure the current drawn on each
phase / circuit
Shelves Visual check for fit and damage
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5.2.1 Cleaning
The product's outer surface may be cleaned with a damp cloth. Do not allow water to
enter the interior of the case or chamber. Do not clean with organic solvents.
Under no circumstances should any objects be placed on top of the
product. Always ensure that any vents on the top of the product are clear
of any obstruction. Always ensure all cooling vents and cooling fans (if
fitted) are clear of any obstruction.
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 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 a fan and motor assembly, a thermocouple, a solid state relay, an
element (or set of elements) and a door seal. Individual spare parts are also available.
When ordering spare parts please quote the model details as requested above.
5.6 Power Adjustment
The control system incorporates electronic power limiting, but for the model listed in
this manual the power limit is set to 100%. The power limit parameter OP.Hi may be
accessible to the operator, but should not generally be altered.
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In some cases the supply voltage may be outside the range 220-240 V or the 3-phase
equivalent, the power limit parameter may be set to a value other than 100%. Do not
increase the value to 100%, see section 7.0 for details of power limit settings.
14

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 Panel Removal
Disconnect the product from the electrical supply.
15

Remove the screws holding the panel. Do not disconnect any wiring without first
making a careful note of all the connections.
For the internal element cover. Open the door. Remove any screws holding the panel
and any clips holding thermocouples in position. Remove the cover.
6.4 Temperature Controller Replacement
Refer to the controller instructions for more information on how to replace the
temperature controller.
6.5 Fuse Replacement
Fuses are accessed by removal of the appropriate panel, as described in the 'Panel
Removal' section. Depending on the model, supply fuses and control circuit fuses may
be mounted in their own holders, or may be on a circuit board that contains an EMC
filter. The fuses are marked with their ratings.
Take care not to disconnect the wires leading from the EMC filter without first recording
their positions: they must be reconnected to the correct terminals.
Note: The main fuses for PF 30 models are located in an external fuse holder
positioned next to the IEC socket for the power supply cable.
16

6.6 Element Replacement
lRemove the cover plate over the element tails on top of the oven.
lOpen the door and remove the shelves and the element cover. The elements will be
directly in front of you.
lRelease the gland nut on the compression fitting holding the element, and remove
the element.
lFit the new element using new olives.
lRefit the electrical connections and covers.
6.7 Thermocouple Replacement
Disconnect the product from the power supply. Remove the appropriate
panel to gain access to the thermocouple connections. Make a note of the
thermocouple connections.
Thermocouple cable colour codings are:
Thermocouple leg Colour
positive (type K) green
negative white
Undo any clips holding the thermocouple. Remove the air guide from the oven
chamber. Disconnect the thermocouple from its terminal block. Unscrew the
compression fitting inside the chamber and pull the thermocouple into the chamber.
Cut through the thermocouple behind the olive and remove the two parts. Loosely
assemble compression fitting with a new ferrule. Feed in new thermocouple through
from the back. Tighten the compression fitting. Refit the air guide. Bend the
thermocouple to match the shape of the previous part and refit any clips.
Refit the element access panel.
Compression fittings are only fitted to moisture extraction and stoving and curing
products. If fitted, ferrules need replacing.
6.8 Solid-state Relay Replacement
Disconnect the product from the electrical supply and remove the
product's access panel. The access panel is located at the top of 'A'
models and the right hand side of 'B' models.
Make a note of the wiring connections 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 bottom of the solid state
relay connects securely to the base panel or aluminium plate, as good thermal contact
is required.
Replace the removed panel.
17

7.0 Fuses and Power Settings
7.1 Fuses
F1 - F2: Refer to the circuit diagrams.
F1
Internal
Supply
Fuses
Fitted if supply cable fitted.
Fitted on board to some types
of EMC filter.
38 mm x 10 mm type F fitted on
EMC filter circuit board(s)
F2 Auxiliary
Circuit Fuses
Fitted on board to some types
of EMC filter.
May be omitted up to 25 Amp/
phase supply rating.
2 Amps glass type F
On board: 20 mm x 5 mm
Other: 32 mm x 6 mm
Customer
Fuses
Required if no supply cable
fitted.
Recommended if cable fitted.
See rating label for current;
See table below for fuse rating.
Model Phases Volts Supply Fuse Rating (Amps)
F1
CDHT/450 3 Phase + No Neutral 208V 32 A
7.2 Power Settings
The power limit settings (parameter OP.Hi) for this model are voltage dependant. The
figures represent the maximum percentage of time that controlled power is supplied to
the elements. Do not attempt to “improve performance” by setting a value higher than
the recommended values. To adjust the parameter refer to the "Changing the Maximum
Output Power" of the control section of the manual.
Please refer to the rating label for product specific information.
18

8.0 Fault Analysis
A. Oven Does Not Heat Up
1.
The
temperature
controller is
OFF
No power from
supply
Check the fuses in the supply
line
2.
The
temperature
controller is
ON
The controller
shows a very high
temperature or a
code such as EEE
or --- or S.br
The temperature sensor has
broken or has a wiring fault
The controller
shows a low
temperature
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 controller may be faulty or
not receiving a supply due to a
faulty switch or a wiring fault
B. Oven Overheats
1.
Oven only
heats up
when the
instrument
switch is ON
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 oven
The thermocouple may be
connected the wrong way round
The controller may be faulty
2.
Oven heats
up when the
instrument
switch is OFF
The SSR has failed
"ON"
Replace the SSR. Check for an
accidental wiring fault which
could have overloaded the SSR
19

9.0 Wiring Diagrams
For wiring diagrams, please contact Carbolite Gero Service. Please quote the serial
number and model.
20