Operation Manual

LOW TEMPERATURE LABORATORY ELECTRIC FURNACE
FD 420/300
Operation Manual
The product conforms to the requirements of the European Union Low Voltage Directive
2006/95/EC, Electromagnetic Compatibility Directive 2004/108/EC, and Machinery Safety Directive
2006/42/EC.
PLEASE READ THIS MANUAL CAREFULLY BEFORE OPERATION
3, Hagavish st. Israel 58817 Tel: 972 3 5595252, Fax: 972 3 5594529 mrc@mrclab.com
MRC.VER.01-8.12
1. PURPOSE
Low temperature laboratory electric furnace FD 420/300 is designed for heating or drying
materials and stocks in the ambient air temperatures from T+100C to 3000C in static conditions.
2. EXPLANATION OF SYMBOLS AND MARKINGS
Explanation of markings
alternating current
grounding contact
danger of electrical shock
control of the fan valve
Position of the label of the product and explanation
Identification on the label
Model : FD 60/300
IP 20
No 0000000
220V
~50 Hz
2,0 kW
50kg
10 2008
Meaning
Type of furnace, 60 – total chamber volume (60 dm3);
300 – nominal temperature (300ºC).
Degrees of protection provided by enclosures EN60529
Number of the product
Voltage of power supply 220 V
Frequency of electrical current, Hz
Nominal power, kW
Weight of the product, kg
Date of manufacture (month, year)
Mark of compatibility to CE
Explanation of symbols
This symbol indicates important safety requirements disregard of
which may cause risk to personal safety and /or to property. Before
switching on the low temperature furnace, it is very important to read
and follow all the instructions of this manual.
This symbol indicates the articles of the manual requirements which
must be followed with great care in order to ensure the correct
sequence of operations and prevent damage to the furnace and danger
to operators.
Attention
This symbol indicates important information.
3. COMPLEMENT
The user is supplied with:
Name
Quantity
Electrical furnace
Shelves
Passport
User manual of
temperature
controller
Fuse
FD 420/300
pcs.
pcs.
pcs.
psc.
1
3
1
1
pcs.
2
4. SAFETY REGULATIONS
Use the electric furnace according to the requirements of „Users’ technical safety operation
rules of electric equipment“.
The operator working with the electric furnace must be aware of the operation rules of electric
equipment up to 1000V, is acquainted with safety regulations for operation of electric furnace, and
is aware of the structure, operation principle, assembly and operation rules of the product.
Connect the electric furnace to the mains (power supply) that must have the grounding contact
connected to the grounding circuit.
It is prohibited to operate the electric furnace if the grounding is insecure.
It is prohibited to operate the electric furnace if any of external protective shields is
removed.
If the electric furnace is operated for a longer period of time, the external surfaces
and the door may get hot. When opening the door of the hot electric furnace as
well as loading/unloading it or when touching hot external surfaces, it is necessary
to wear gloves.
Attention
Combustible or explosive materials or materials that can become combustible or
cause explosion during thermal treatment must not be loaded into the low
temperature furnace
Do not load the furnace with unknown materials
Attention
The gas emitted during thermal treatment has to be directed outside through a
ventiduct (according to the rules of existing requirements).
The room where the furnace is operated must have appropriate ventilation
It is forbidden to work in closed, not ventilated room
The room where several furnaces are operated must have special means of
ventilation
In the event of obvious violations the work with the furnace must be immediately
stopped. Maintenance can be performed by our service operator, our authorized
specialist or a user who strictly follows our written maintenance instructions.
In the event the normal operation of the furnace breaks down, disconnect it from
the power supply (the mains) and take measures to eliminate the defects.
It is forbidden to use the furnace for any other purposes. The manufacturer is not
responsible for damages arising from the use of the furnace not according to its
purpose; the responsibility is carried by the user.
Any work that can affect the safety of the furnace must be forbidden
The existing rules of general safety and prevention of accidents should be
applied.
Only technically orderly furnace must be operated.
If these instructions are not observed, the user is responsible for any negative
consequences.
The manufacturer‘s advice can not cover all issues, therefore the user is responsible for the
heating impact on materials and their reaction as well as for the risk related with tests. Our advice
will help to avoid possible dangers for people, the furnace and materials tested.
5.2. Technical characteristics
°C
°C
FD
420/300
6,2
380
50
IP20
300
3
Air
±0,3
T+10 ÷300
±°C
±°C
±°C
±°C
min.
±0,7
±2,5
±5,3
±7,4
30
Width
Depth
Height
mm
mm
mm
1000
500
860
Number of shelves
(standard/max)
Non-concentrated load of one
shelf
Total limiting load
Overall dimensions of Width
the furnace not more
Depth
than:
Height
Weight
pcs.
3/7
Kg
15
Kg
mm
mm
mm
Kg
50
1200
930
1200
155
Measure
Nominal power
Voltage
Frequency
Exploitation class (EN60529)
Nominal chamber temperature
Number of phases
Ambience in the chamber
Temperature fluctuations*
Limits of automatic temperature
control**
Temperature
50°C
distribution****
100°C
200 °C
300 °C
Heating time from
300°C
5°C to, not more
than: :
Dimensions of the
chamber not less
than:
kW
V
Hz
IP20
°C
*Temperature fluctuations at steady mode, without load. The value of the parameter is given after
temperature AT controller has been chosen (see instruction manual temperature controller).
** Temperature control limits from the temperature (T+10ºC) to 300ºC. T- the ambient temperature of the
room where the furnace is operated.
****Temperature distribution in the working space with forced convection when revolutions of engine are
100% (the fan revolution controller shows 10), at indicated temperatures.
6. PECULIARITIES OF OPERATION
Electric furnace has to be operated in a closed ventilated room following these requirements:
- the base under the bottom of the electric furnace has to be horizontal
(the allowed unevenness in the length of 1m is ± 1mm.), hard, made
of incombustible material;
- height above sea level – up to 2000 m;
- ambient temperature from +5 to +40°C;
- ambient relative air humidity should not exceed 80% at the
temperature of +31°C, and should not exceed 50% at the temperature
of +40°C;
- the voltage fluctuation in the mains (power supply) should not exceed
± 10% of the nominal value;
- the environment is not dangerous with respect to explosion, it does not
contain a large amount of electrically conductive dust, water vapour,
aggressive gas;
- recommended to be placed under the exhaust ventilation cap;
- the electric furnace should not be affected by vibration and shocks;
- it is prohibited to exceed the nominal temperature, otherwise the
service life of heating elements is shortened and the thermocouple
might be damaged.
7. ASSEMBLY
Unpack the electric furnace and place it in the location prepared for its operation. Unscrew
the supports and remove the transportation plates. Fix the supports. With the help of supports
adjust the position of the furnace. Put in the shelves. Connect the plug of the power supply cord to
the mains (power supply) socket with the grounding contact connected to the grounding circuit.
The voltage specified in the table of technical parameters should be in conformity with nominal
voltage of the mains (power supply).
8.PREPARATION FOR OPERATION
Before the first operation or if the electric furnace has not been in use for a long period of
time and stored in humid conditions, it should be dried as follows:
- without load heat it up to the temperature of 100-150°C and maintain it for 2-3 hours;
- heat it up to the nominal temperature. Maintain for 1-2 hours.
The dried furnace can be operated.
While drying some smoke may appear but it has no effect on further operation of the
electric furnace.
9.ORDER OF OPERATION
Open the doors of the electric furnace.
Put the load on the shelves leaving the spaces from the walls of 1/10 of the side for the better
circulation of air.
The data indicated in technical characteristics were obtained in the working space.
A,B,C – dimensions of the chamber;
a, b, c – spaces between the walls and the
load;
a= A x 0,1
b= B x 0,1
c= C x 0,1
Working volume (space)
V = (A-2a) x (B-2b) x (C-2c)
Close the door of the electric furnace.
Turn on the switch; the switching-on will be indicated by the pilot lamp that lights up.
Following the User Manual of the temperature controller set the necessary program and
switch its execution on.
The speed of air flow can be adjusted according to the demand. 0 – means natural convection
in the chamber (the fan does not work), 10 – means forced convection (the fan works at max.
revolutions).
Increase of the revolutions of the fan
( 0 – 10)
Decrease of the revolutions of the fan
(10 -0).
While decreasing the revolutions of the fan the temperature distribution in the chamber
worsens.
The air change in the chamber can be adjusted according to the process in the furnace.
The fan valve is fully closed. The ambient air does not get
into the chamber.
The fan valve is fully open. The ambient air gets into the
chamber.
In the technical characteristics the change of air (times per hour) in the chamber is stated
when the fan works at maximal revolutions and the fan valve is fully open.
If the valve of the change of air is open, the temperature distribution in the furnace
worsens.
After work switch off the furnace. The switching-off will be indicated by the pilot lamp that fades.
When program ends the bell sounds. With thermocontroller E5CKT – the bell is switched off with
button on the control panel.
10. MAINTENANCE
The electric furnace should be disconnected from the mains (power supply) and
cooled.
Attention
Control
of
door tightness
Change
fuse
Once a year
of
Press the holder of the fuse, turn anticlockwise and take out from the
socket. Change a burnt-out fuse. Screw in the holder of the fuse in the reverse
order.
Once a year measure the insulation resistance between the frame and
heating elements. Dry up the electric furnace. Connect the megohmmeter to the
leads of heating element and frame. The reading of the megohmmeter should not
be less than 0,5 MΩ.
Once per six months examine visually the wires and electrical connections.
Once in six
If necessary, tighten the contact screws.
months
When the operation is over, clean the external surfaces of the electric
Cleaning
furnace, except the marking, with a piece of cloth soaked in water. Clean out the
scale from the heating chamber with a piece of cloth soaked in water.
Clean the fan apertures by the means of a vacuum cleaner.
Cleaning of
the
fan
apertures
11. STORAGE
Store the electric furnace in its packing in:
• heated and naturally ventilated room at the ambient temperature from +5 to
+35°C;
• atmosphere with sulphurous gas concentration not exceeding 0,13 mg/m³ and
chlorine salts concentration not exceeding 0,3 mg/m² per 24 hours;
• the ambient relative air humidity not exceeding 80% at the temperature of 25°C
While loading and unloading the furnace, protect it from any shocks.
12. TRANSPORTATION
The electric furnace has to be transported only in closed transport at temperatures from - 50
to + 50°C; at the temperature of +25°C, the ambient relative air humidity must not exceed 80%;
You can transport the electric furnace by any means of closed transport, except the sea
transport, but protect it from any movement and rough mechanical damages. The packaging does
not protect the electric furnace from the effects of improper treatment.
13. WARRANTY
The manufacturer guarantees that the electric furnace meets the requirements of the
company standards.
The guaranteed operating period is 12 months from the date of purchase of the furnace
provided that the user follows the rules of storage and transportation and operation instructions, but
not more than 24 months from the date of the manufacture of the furnace.
The defects that appear during the warranty period through the manufacturer’s fault shall be
eliminated at manufacturer’s expense.
14. THE MORE OCCURRED FAILURES AND REMOVAL METHODS
Failure
Reason
Removal method
There
is
no
rated
power
To check the power supply
The oven can’t turn on.
The oven can’t heat.
Heating time is longer
than determined
supply voltage
The fuse is burnt out
The temperature controller is
not switched on
Damaged heating element
Damaged thyristor relay
Low voltage of the power
supply
Door’s close is not hermetic
There
automatic
regulation.
is
To change the fuse
To switch on temperature
controller
Change heating element
Change thyristor relay
To check the voltage of
power supply
To regulate tightness of
door’s close
Temperature’s regulator is
To switch on automatic
no exact
selection of parameter (AT) (look to
temperature not regularized
temp. regulation
users)
instruction
for
* If after switching on the protective device it triggers again, the furnace must not be operated. In
that case the manufacturer or the manufacturer‘s representative should be addressed for the
repairs of the furnace.
15.
ASSESSMENT TECHNIQUE OF THE PARAMETERS OF THE LABORATORY
ELECTRIC FURNACE
Assessment is performed when the fan works at maximum revolutions and the valve of the
fan is closed. Parameter is given after temperature AT controller has been chosen ( see instrukcion
manual temperature controller).
The parameters that are tested:
1. Testing of the nominal temperature and temperature stability without load when the low
temperature laboratory electric furnace is heated to the nominal temperature.
2. Temperature distribution in the working space without load when the low temperature
laboratory electric furnace is heated to the nominal temperature.
TESTING METHODS
All tests are performed when the low temperature laboratory electric furnace is heated to the
nominal temperature and works in the mode of steady temperature, i.e. when the temperature of the
furnace corresponds to the nominal temperature and temperature fluctuations reach minimal values
(e.g. 300±10C).
1. The testing of the nominal temperature and temperature stability without load when the
low temperature laboratory electric furnace is heated to the nominal temperature is performed as
following:
In the cold furnace the pilot thermocouple is fixed as closely as possible to the working
thermocouple. The time period of the testing of the nominal temperature and temperature stability
is 1 hour. The readings of the control device have to be registered, for example, every 10 minutes.
The estimation of the nominal temperature:
The sum of all registered temperature values is divided by the number of records made. The
result must be from 299 0C to 301 0C. The temperature stability is estimated at the same time. If
during the temperature testing the result is positive, that means that the temperature stability
conforms to the requirement 300±10C.
2. The testing of the temperature distribution in the working space without load when the low
temperature laboratory electric furnace is heated to the nominal temperature is performed with the
help of pilot thermocouples and the device showing temperature. No fewer than five
thermocouples should be used. Thermocouples have to be arranged at the distance of 1/10 (for
example, if the length of the wall is 380 mm, the thermocouple has to be not closer than 38 mm
from the wall) from each wall and one thermocouple has to be put in the centre of the chamber. For
fixing of thermocouples we recommend to make a welded frame. The results are estimated
according to the formula.
The estimation of the temperature distribution in the working space: maximum testing
temperature from one point minus minimal temperature from another point divided by two.
The temperature distribution must be not higher than ±2,00C.
All instruments and thermocouples used for testing must be assessed, metrologically tested
and be of not lower than the first class of accuracy.
17. OVEN TESTING RECORD
The laboratory model FD 420/300
was tested and correspond company standards
requirements.
Serial No ____________________________
.
Produced ________________________
Control department seal and signature _________________________
Code of the product ______________________________________
Attention!
In the line of continuous improvement insignificant design amendments may be introduced
without notice in this publication.