MELAG Type 215 User manual

page 1
Operating Instructions
HOT- AIR STERILIZERS
DRYING CABINETS
Models with
Mechanical Air Movement
Type 215 Type 225 Type 255
Sterilization - Disinfection
Sterilization means to free objects from breedable
microbes; in the process not only the vegetative, but
the resistive forms of germs must be eliminated.
Sterilization by hot air requires a minimum
temperature of 180°C (German DIN 58947). During
sterilization, spores of type A, B, C, D (according to
the German federal public health department) or
spores of resistivity level III (according to Prof.
Konrich) have to be killed.
The only result of disinfection is that an object
cannot disinfect any more. It is then free from
vegetative forms of disease-causing agents, but not
free from bacterial spores.
Medical instruments which come into contact with
blood or which injures the integrity of human body
surface, must therefore always be sterilized before
use (tetanus and danger of gangrene infection) –
disinfection is not sufficient.
What can be sterilized in hot-air?
In hot-air, it is possible to sterilize objects made of
incombustible (inorganic) materials, such as metal,
glass, porcelain, stoneware, enamelware, etc., e.g.
instruments, syringes, cannulas, and so on (pay
attention to the manufacturer's instructions). After
use, the instruments, syringes, etc. should
immediately be disinfected and then thoroughly be
cleaned. Before placing them in the sterilizer, the
items have to be dried. Do not place items on
cellulose because this might lead to build-up of heat
and thus to an obstruction of heat egalization in the
apparatus.

page 2
1. Operation of the apparatus
Set up the temperature regulator (1) to the sterilizing
temperature of 180°C. If the indicated value for
temperature is different from the one set up, check
for a possible adjustment of the regulating knob (see
"Hints for fault corrections" below).
1.1. Switching on power_______________________________________________
The apparatus' with timer is switched on by adjusting
the timer (5) to the time given in the operating time
table. The permanent switch (6) of sterilizers of type
215-255 must always be in position "0", if the timer is
in operation.
For longer processes (or if the timer is defective),
power can be switched on by using switch (5) for the
required time. The timer is out of operation. By
turning the timer knob counter-clockwise (to the left
to "I"), the sterilizer is turned on for permanent
operation.
The light of signal lamp (4) indicates that power is
on.
The signal lamp (2) optically shows the automatic
working procedure of the temperature regulator. It
keeps the adjusted temperature to a constant level
by turning the heating on or off (not current in
general). Lamp (2) goes on and out respectively.
1.2. Switching off power ______________________________________________
The apparatus is automatically switched off at the
end of the timer (5).
If a sterilization process was carried out by using the
permanent switch (6), set it back to position "0".
Permanent operation of sterilizers of type 71 and
type 91 is ended (timer in position "I") by setting the
timer knob back to "0". Both signal lamps (2 and 4)
go out if power is turned off.
1.3. Mechanical Air Movement__________________________________________
Sterilizers with mechanical air movement have
motor-driven fans which are automatically switched
on by the turning on of power and switched off re-
spectively.
1.4. Drying procedure_________________________________________________
Set up temperature to 100°C by turning the regula-
tion knob. Shake out pipettes to be dried and lay
them in not too wet and – if possible – a little sloping.
Escape of damp air is possible as follows:
As far as sterilizers of type 215-255 are concerned,
the door can be engaged into a position of the door
hinge where the door will be kept open to enable the
drying process.
2. Description of the apparatus
2.1. Front view_______________________________________________________
Type 215 - 255
1
Thermostat
3
Thermometer
5
Timer - On-Off Switch
2
Signal lamp heating
4
Signal lamp main
6
Permanent switch
5
2
1
6
4
3

Operating Instructions
page 3
Table of Operating Times
Apparatus
Type
Maximum load
(without basket/trays)
Mechanical
air movement
215 / 225 / 255 3,0 kg 70 Min. (3 trays)
85 Min. (6 trays)
The given operating times are based on sterilizations
of medical instruments with trays or open containers.
Sterilization processes with closed containers need
longer operating times (see below).
Use containers from aluminium not stainless steel
container. Determine the additional time by a test
run. The safety margin should be 10%.
2.2. German VDE-requirements _________________________________________
In accordance with the valid VDE-requirements, this
autoclave is not suitable for areas with danger of
explosion.
It may be repaired only by the manufacturer or a
licensed service unit.
3. Attention! Warning
•Before opening the door switch off the appliance,
either using the main switch (6) or by turning the
time switch (5) to “0”. The signal lamp (4) is no
longer on.
•Be careful when loading and unloading the hot
sterilizer. Trays and sterilised items are hot!
•The ventilator only comes to rest some 45 secs
after switching off the appliance.
•During and after the sterilisation process some
parts of the housing may become very hot and
could cause burns. Danger!
•This appliance is not suitable for the sterilization
of liquids and for the warming up of rinse
solvents !
4. Attention! Misoperation
The hot-air sterilisszation method is fully accepted
(German DIN 58947). Nevertheless, this method is
still criticized because bacteriological examinations
about hot-air sterilizers still show a growth of testing
germs. A more detailed examination demonstrates
that this fact is mostly caused by misoperation.
5. Fault No. 1: Operating time too short!
The operator assumes the correct fact that a tem-
perature of 180°C for a period of 30 minutes takes
effect on the items to be sterilized. But the fault lies
in the exclusive observation of the thermometer. As
soon as the thermometer shows a temperature of
180°C, the operator wrongly begins to count the 30
minute period after which the sterilizer can be
switched off. This procedure only considers the pre-
heat time but not the equalization time. It is wrong to
assume that the killing time starts immediately after
the conclusion of the pre-heat time. Between killing
and pre-heat time, the operator has to take the
equalization time into account. This is the time
needed for the required temperature reaching all
places of the apparatus and of the items to be steril-
ized. Only after conclusion of the equalization time
the killing time begins which endures 30 minutes
(with 180°C). This period contains an extra charge
for safety (German DIN 58947, part 5).
All these conclusions of times are included in the
operating times given above (see table). The operat-
ing times are based on sterilizations of medical
instruments under use of trays or open containers.
Sterilization processes with closed containers need
longer operating times. If the items are sterilized in
closed cassettes made of aluminium with thin walls,
the operating times have to be elongated for 15
minutes. On principle, we recommend not to use
closed containers. For example, we have measured
a temperature of only 160°C inside of plates after 3½
hours!

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6. Hints about fault corrections
6.1. Timer does not automatically switch off power ________________________
If the timer is defective, the sterilizer can still be
operated in a half-automatic way with the help of the
permanent switch (6). Before exchange of the timer,
it is absolutely necessary to pull out the main plug.
Loosen the screw of the timer knob and remove the
knob. Unscrew the front scale plate and remove it
with care. Then remove the stick hulls of the cable
ends from the flat plugs of the timer and unscrew the
timer from the front scale plate. Connect and install
the new timer in the same way.
A new timer can only be ordered at specialist shops.
For quick completion, it is necessary to know the
type of sterilizer and its work number.
6.2. Temperature set up with the regulation knob does not tally with
indication of the thermometer _______________________________________
Hot-air sterilizers from MELAG are delivered with
temperature calibrated at 180°C by adjusting the
regulator axis so that the thermometer really
shows a value of 180°C. Then the thermostat
knob is sticked on the axis so that the white
indicator of the knob points to the 180°C- mark on
the scale. In this position, the thermostat knob is
fixed to its axis by fastening the clamp screw.
If the thermostat knob is unintentionally be turned
with force beyond the resistance due to improper
treatment, e.g. during cleaning or unpacking of the
gadget, or if the screw is loosened in the taper, the
knob can slip on the regulator axis. Respectively,
the real temperature inside the vessel (indicated
on the thermometer) is different from the one set
up on the regulator scale.
A quick correction can easily be achieved by
turning the thermostat knob either little clockwise
in order to obtain a higher temperature, or
counter-clockwise for lower temperature. Provi-
sional markings on the scale will help adjustment.
A correct calibration is carried out as follows:
Remove the grey cap from the thermostat knob.
After loosening the clamp screw below, the knob
can be removed from the axis. Close the door and
switch on the sterilizer. Now adjust the tem-
perature regulator by turning the axis (perhaps
with small pliers) so that the thermometer shows
the desired temperature (e.g. 180°C) after con-
clusion of pre-heat and equalization time. Put the
thermostat knob back on the axis so that the white
indicator points to a value on the scale which
agrees with the temperature shown on the
thermometer. Finally screw the knob's screw tight
without changing the position of the axis.
6.3. The appliance does not heat up _____________________________________
If your hot air steriliser does not work, check the
internal fuses. To change fuses, first disconnect
the appliance from the mains power supply. Press
down the tongue on the fuse container on the rear
side of the oppliance and pull the container out.
Inspect the fuses and exchange if necessary.
If the signal lamp (4) does not light up to show that
the power is on, check the cable, power socket,
and mains fuse.
If the signal lamp (4) lights up but not signal lamp
(2), check the setting of the control knob (see 1.
above).
7. Appendix
7.1. Spare parts ______________________________________________________
Article No.
Description
32985
door seal (type 215-225)
92995
door seal (type 255)
32890
thermostat
32930
timer
33470
thermometer
16450
mains fuse 6,3A 2x