Phcbi MDF-U443 User manual

MDF-U443

Please read the operating instructions carefully before using this product, and keep the operating
instructions for future use.
See page 35 for model number.
Operating Instructions
Biomedical Freezer

1
CONTENTS
INTRODUCTION P. 2
PRECAUTIONS FOR SAFE OPERATION P. 3
LABELS ON UNIT P. 7
SYMBOLS ON UNIT P. 8
ENVIRONMENTAL CONDITIONS P. 8
INTENDED USE AND PRECAUTIONS P. 8
FREEZER COMPONENTS P. 9
Control panel P. 11
INSTALLATION SITE P. 12
INSTALLATION P. 13
START-UP OF UNIT P. 14
Operation after power failure P. 14
CHAMBER TEMPERATURE SETTING P. 15
KEY LOCK FUNCTION P. 15
FUNCTION MODE P. 16
SETTING OF ALARM DELAY TIME P. 16
SETTING OF TEMPERATURE ALARM P. 17
SETTING OF ALARM RESUME TIME P. 18
SETTING OF DOOR ALARM DELAY TIME P. 19
SETTING OF COMPRESSOR DELAY TIME P. 20
DEFROSTING P. 21
Automatic defrosting P. 21
Manual defrosting P. 21
Sub-heater switch P. 21
REMOTE ALARM TERMINAL P. 22
ALARMS & SAFETY FUNCTIONS P. 22
ROUTINE MAINTENANCE P. 24
Cleaning of cabinet P. 24
Cleaning of evaporating tray P. 24
Cleaning of condenser filter P. 25
Defrosting of chamber P. 25
CALIBRATION P. 25
DISPOSAL OF BATTERY P. 26
TROUBLESHOOTING P. 27
DISPOSAL OF UNIT P. 28
Recycle of battery P. 28
Decontamination of unit P. 28
TEMPERATURE RECORDER (OPTION) P. 33
SPECIFICATIONS P. 34
PERFORMANCE P. 35
SAFETY CHECK SHEET P. 36

2
INTRODUCTION
■Read the operating instructions carefully before using the product and follow the instructions for safe
operation.
■PHC Corporation takes no responsibility for safety if the product is not used as intended or is used with
any procedures other than those given in the operating instructions.
■Keep the operating instructions in a suitable place so that they can be referred to as necessary.
■The operating instructions are subject to change without notice for improvement of performance or
function.
■Contact our sales representative or agent if any page of the operating instructions is lost or the page
order is incorrect, or if the instructions are unclear or inaccurate.
■No part of the operating instructions may be reproduced in any form without the express written
permission of PHC Corporation.
IMPORTANT NOTICE
PHC Corporation guarantees this product under certain warranty conditions. However, please note that
PHC Corporation shall not be responsible for any loss or damage to the contents of the product.

3
PRECAUTIONS FOR SAFE OPERATION
It is imperative that the user complies with the operating instructions
as it contains important safety advice.
Items and procedures are described so that you can use this unit correctly and safely.
If the precautions advised are followed, this will prevent possible injury to the user and
any other person.
Precautions are illustrated in the following way:
WARNING
Failure to observe WARNING signs could result in a hazard to personnel
possibly resulting in serious injury or death.
CAUTION
Failure to observe CAUTION signs could result in injury to personnel and
damage to the unit and associated property.
Symbol shows;
T
his symbol means caution.
T
his symbol means an action is prohibited.
T
his symbol means an instruction must be followed.
Be sure to keep the operating instructions in a place accessible to users of this unit.

4
PRECAUTIONS FOR SAFE OPERATION
Do not use the unit outdoors. Current leakage or electric shock may result if the unit is exposed to
rain water.
Only qualified engineers or service personnel should install the unit. The installation by
unqualified personnel may cause electric shock or fire.
Install the unit on a sturdy floor and take an adequate precaution to prevent the unit from
turning over. If the floor is not strong enough or the installation site is not adequate, this may result
in injury from the unit falling or tipping over.
Never install the unit in a humid place or a place where it is likely to be splashed by water.
Deterioration of the insulation may result which could cause current leakage or electric shock.
Never install the unit in a flammable or volatile location. This may cause explosion or fire.
Never install the unit where acid or corrosive gases are present as current leakage or electric
shock may result due to corrosion.
Always ground (earth) the unit to prevent electric shock. If the power supply outlet is not
grounded, it will be necessary to install a ground by qualified engineers.
Never ground the unit through a gas pipe, water main, telephone line or lightning rod. Such
grounding may cause electric shock in the case of an incomplete circuit.
Connect the unit to a power source as indicated on the rating label attached to the unit. Use
of any other voltage or frequency other than that on the rating label may cause fire or electric shock.
Never store volatile or flammable substances in this unit if the container cannot be sealed. These
may cause explosion or fire.
Do not insert metal objects such as a pin or a wire into any vent, gap or any outlet on the unit.
This may cause electric shock or injury by accidental contact with moving parts.
Use this unit in safe area when treating the poison, harmful or radiate articles. Improper use
may cause bad effect on your health or environment.
Turn off the power switch (if provided) and disconnect the power supply to the unit prior to
any repair or maintenance of the unit in order to prevent electric shock or injury.
Do not touch any electrical parts (such as power supply plug) or operate switches with a wet
hand. This may cause electric shock.
WARNING

5
PRECAUTIONS FOR SAFE OPERATION
Ensure you do not inhale or consume medication or aerosols from around the unit at the time of
maintenance. These may be harmful to your health.
Never splash water directly onto the unit as this may cause electric shock or short circuit.
Never put containers with liquid on the unit as this may cause electric shock or short circuit when
the liquid is spilled.
Never bind, process, or step on the power supply cord, or never damage or break the power
supply plug. A broken supply cord or plug may cause fire or electric shock.
Do not use the supply cord if its plug is loose. Such supply cord may cause fire or electric shock.
Never disassemble, repair, or modify the unit yourself. Any such work carried out by an
unauthorized person may result in fire, or electric shock or injury due to a malfunction.
Disconnect the power supply plug if there is something wrong with the unit. Continued
abnormal operation may cause electric shock or fire.
When removing the plug from the power supply outlet, grip the power supply plug, not the cord.
Pulling the cord may result in electric shock or fire by short circuit.
Disconnect the power supply plug before moving the unit. Take care not to damage the power
supply cord. A damaged cord may cause electric shock or fire.
Disconnect the power supply plug when the unit is not used for long periods. Keeping the
connection may cause electric shock, current leakage, or fire due to the deterioration of insulation.
If the unit is to be stored unused in an unsupervised area for an extended period, ensure that
children do not have access and that doors cannot be closed completely.
The disposal of the unit should be accomplished by appropriate personnel. Remove doors to
prevent accidents such as suffocation.
Do not put the packing plastic bag within reach of children as suffocation may result.
Do not position this unit and the other unit so that it is difficult to operate the disconnection of
the power supply plug. Failure to disconnect the power supply plug may cause fire if there is
something wrong with the unit.
WARNING

6
PRECAUTIONS FOR SAFE OPERATION
This unit must be plugged into a dedicated circuit protected by branch circuit breaker.
Use a dedicated power source as indicated on the rating label attached to the unit. A
multiple-tap may cause fire resulting from abnormal heating.
Connect the power supply plug to the power source firmly after removing the dust on the plug.
A dusty plug or improper insertion may cause a heat or ignition.
Never store corrosive substances such as acid or alkali in this unit if the container cannot be
sealed. These may cause corrosion of inner components or electric parts.
Check the setting when starting up of operation after power failure or turning off of power
switch. The stored items may be damaged due to the change of setting.
Be careful not to tip over the unit during movement to prevent damage or injury.
Prepare a safety check sheet when you request any repair or maintenance for the safety of service
personnel.
CAUTION

7
LABELS ON UNIT
Warning safety labels applied to the biomedical freezer
Users are advised to avoid accidents by carefully reading the warnings and cautions contained on
warning labels at key locations on the interior and exterior of the biomedical freezer.
Possible
Danger
Warning/Caution Type
Location of Danger
Warning/Caution Label Description of Danger
Personal
injury
Electric shock
Top cover Never remove this cover. Only a
service personnel remove the
cover to avoid the electric shock.
Personal
injury/
Sample
damage
Frostbite and
chamber temperature
rise
Interior
Sample in the chamber touch
wearing gloves. There is a risk of
frostbite.
When it uses for a long time, frost
appears on the chamber wall
side. It cannot be cooled down
when there is much amount of
frost.
Personal
injury/
Sample
damage
Injury or damage
Human/inserted things
Failure of equipment
Interior
When inserting your finger/
something into the fan cover,
circulating fan injures/crashes it.
Circulating fan motor may fail by
water.
Sample
damage
Spoiling of sample
Interior Cold air leakage results in a rise
in chamber temperature.
This may spoil cryopreserved
samples in the chamber.
Sample
damage
Spoiling of sample
Interior Blocking the air intake reduces
the cooling performance of this
equipment.
This may spoil cryopreserved
samples in the chamber.
Sample
damage
Spoiling of sample
Interior Sample located below the load
line is obstacle to cold air
circulation.
This may spoil cryopreserved
samples in the chamber.
Equipment
damage
Damage of equipment
Exterior Equipment is deformed by hitting.

8
SYMBOLS ON UNIT
The symbols are attached to the biomedical freezer. The following table describes the symbols.
This symbol is attached to covers that access high-voltage electrical components to
prevent electric shock. Only a qualified engineer or service personnel should be
allowed to open these covers.
This symbol indicates that caution is required. Refer to product documentation for
details.
This symbol indicates an earth.
This symbol means “ON” for a power switch.
This symbol means “OFF” for a power switch.
ENVIRONMENTAL CONDITIONS
This equipment is designed to be safe at least under the following conditions (based on the IEC
61010-1):
■Indoor use;
■Altitude up to 2000 m;
■Ambient temperature 5 oC to 40 oC;
■Maximum relative humidity 80 % for temperature up to 31 oC decreasing linearly to 50 % relative
humidity at 40 oC;
■Mains supply voltage fluctuations up to ±10 % of the nominal voltage;
■Transient overvoltages up to the levels of OVERVOLTAGE CATEGORY II;
■Temporary OVERVOLTAGES occurring on the mains supply;
■Applicable pollution degree of the intended environment (POLUTION DEGREE 2 in most cases)
INTENDED USE AND PRECAUTIONS
This equipment is designed for low temperature storage of DNAs and plasma.
■The effective storage period depends on the sample condition and storage temperature. It is
necessary to determine the storage temperature and period suitable for the purpose.
■For the plasma, the lower storage temperature should be required for longer term storage. It is
recommended to store the plasma at -80 oC or lower.

9
FREEZER COMPONENTS
12
1
2
4
3
10
7
5
8
9
13
13
11
15 16 17
21 20
22 18
19
6
14
13
Switch
cover

10
FREEZER COMPONENTS
1. Door: To open the door, grip the handle.
2. Door gasket: This provides a tight door
seal and prevents cold air leakage. Keep
clean.
3. Inner door: Transparent acrylic plate
minimizes cold air leakage.
4. Lock: Turn counterclockwise to 180 o
with a key and the door is securely locked.
5. Space for temperature recorder: Refer
to page 38 for installation.
6. Evaporating tray: Defrost water from the
evaporator accumulates on the tray and
evaporates into the atmosphere. See page
24 for cleaning.
7. Control panel: See page 11 for the
details.
8. Leveling foot: These are screw bolts
used to install and fix the unit. Adjust the
height of the leveling feet by turning the
screw bolts until 2 front casters are away
from the floor. See page 13.
9. Caster: Four casters are provided to
facilitate moving of the cabinet.
10. Condenser filter (inside): Clean a
clogged condenser filter. See page 25 for the
details.
11. Latch: This firmly latches the door to
the freezer frame and prevents cold air
leakage.
12. Shelf: Shelf location can be freely
13. Access port (left side, rear side): This is
used for leading the measuring cable from the
chamber to the outside.
14. Fixture (rear side):
15. Lamp: Lights up when door is open.
16. Circulating fan (inside): Sucks in cold air
that has been circulating in the chamber and
sends it out for further circulation after
re-cooling it.
17. Door switch: Stops the circulating fan
when the door is open to prevent cold air
leakage. Also activates the door lamp.
18. Communication box cover:
19. Remote alarm terminal: This is used to
notice an alarm condition of the unit to remote
location. Refer to page 22 “Remote alarm
terminal”.
20. Battery switch ( ): This is a switch for
power failure alarm. Be sure to turn off this
switch to save the battery if the freezer is not in
operation for long period. After installation,
turn on the power switch and battery switch.
21. Sub-heater switch: Normally, turn this
switch ON. Refer to page 21.
22. Power switch: This is for turning ON/OFF
the power to the unit. ON – “I” OFF – “○”
The switch is covered by a switch cover to
prevent the accidental push. To turn on or off
the switch, remove the switch cover by
loosening the screw.
adjusted to match size of stored items.

11
FREEZER COMPONENTS
Control panel
1. Door lamp (DOOR): This indicator lights when the door is open.
2. Alarm lamp (ALARM): This lamp is flashed at the time of power failure or in the event of alarm.
3. Filter check lamp (FILTER): This lamp blinks when the condenser filter is clogged. Clean the
condenser filter according to page 25.
4. Digital temperature indicator: This indicator shows the current chamber temperature or set
temperature. And error code is also indicated in the event of alarm.
5. Numerical value shift key ( ): Pressing this key in the setting mode causes the numerical value to
shift. ON-OFF of key lock can be selected by pressing this key in the key lock setting mode. By
pressing this key for more than 5 seconds in the temperature display mode leads setting mode for alarm
temperature, alarm resume time, door alarm delay time and compressor delay time . Refer to page
15,16,17 and 18 for details respectively.
6. Digit shift key ( ): Pressing this key in the setting mode causes the changeable digit to shift. Key
lock setting mode is led by pressing this key for more than 5 seconds in the temperature display mode.
Refer to page 15 for the key lock function.
7. Set key (SET): Chamber temperature setting mode is led by pressing this key. The changeable
digit is flashed. Pressing this key again after temperature setting memorizes the setting.
8. Defrost key (DEF): When removing the frost, press this key for 5 seconds. The freezer operation is
stopped. After removing the frost, press this key again. See page 21..
NOTE: A defrost key (DEF) doesn't work during the warming up of the product. (Con and chamber
temperature are displayed alternately.)
9. Alarm buzzer stop key (BUZZER): Press this key to silence the buzzer in the event that the alarm
operates and the buzzer sounds. The alarm buzzer sounds again with delay time when the same alarm
status continues (refer to page 18).
10. Alarm test key (ALARM TEST): To check the alarm system during biomedical freezer operation.
Pressing this key with the battery switch ON gets the alarm lamp to flash, the remote alarm to operate,
and the buzzer to sound.
9 8 7 6 5
2 431
10

12
INSTALLATION SITE
To operate this unit properly and to obtain maximum performance, install the unit in a location with the
following conditions:
■A location not subjected to direct sunlight
Do not install the unit under direct sunlight. Installation in a location subjected to direct sunlight cannot
obtain the intended performance.
■A location with adequate ventilation
Leave at least 10 cm around the unit for ventilation. Poor ventilation will result in a reduction of the
performance and consequently the failure.
■A location away from heat generating sources
Avoid installing the unit near heat-emitting appliances such as a heater or a boiler etc. Heat can
decrease the intended performance of the unit.
■A location with little temperature change
Install the unit under stable ambient temperature. The allowable ambient temperature is between +5 oC
and +35 oC.
■A location with a sturdy and level floor
Always install the unit on a sturdy and level floor. The uneven floor or tilted installation may cause
failure or injury. Install the unit in stable condition to avoid the vibration or noise. Unstable condition
may cause vibration or noise.
WARNING
Install the unit on a sturdy floor. If the floor is not strong enough or the installation site is not
adequate, this may result in injury from the unit falling or tipping over.
Select a level and sturdy floor for installation. This precaution will prevent the unit from tipping.
Improper installation may result in water spillage or injury from the unit tipping over.
■A location not prone to high humidity
Install the unit in the ambient of 80 %R.H. or less humidity. Installation under high humidity may cause
current leakage or electric shock.
WARNING
Do not use the unit outdoors. Current leakage or electric shock may result if the unit is exposed to
rain water.
Never install the unit in a humid place or a place where it is likely to be splashed by water.
Deterioration of the insulation may result which could cause current leakage or electric shock.
■A location without flammable or corrosive gas
Never install the unit in a location where it will be exposed to flammable or corrosive gas. This may cause
explosion or fire or may result in the current leakage or electric shock by the corrosion of the electrical
components.
■A location without the possibility of anything fall
Avoid installing the unit in the location where anything can fall down onto the unit. This may cause the
breakdown or failure of the unit.

13
INSTALLATION
1. Removing the packaging materials and tapes
Remove all transportation packaging materials and tapes. Open the doors and ventilate the unit. If the
outside panels are dirty, clean them with a diluted neutral dishwashing detergent. (Undiluted detergent
can damage the plastic components. For the dilution, refer to the instruction of the detergent.) After
the cleaning with the diluted detergent, always wipe it off with a wet cloth. Then wipe off the panels with
a dry cloth.
Note:
Remove the cable tie banding the power supply cord.
Prolonged banding may cause the corrosion of the cord
coating.
2. Adjusting the leveling foot
Stretch the leveling feet by rotating them to contact
them to the floor. Ensure the unit is installed
horizontally. (Fig. 1)
3. Fixing the unit
Two fixtures are attached to the rear of the frame.
(Fig. 2) Fix the frame to the wall with these fixtures
and rope or chain.
4. Ground (earth)
The ground (earth) is for preventing the electric shock in the case of unexpected deterioration of the
electrical insulation. Always ground the unit at the time of installation.
WARNING
Use a power supply outlet with ground (earth) to prevent electric shock. If the power supply outlet is
not grounded, it is necessary to install a ground by qualified engineers.
Never ground the unit through a gas pipe, water main, telephone line or lightning rod. Such
grounding may cause electric shock in the case of an incomplete circuit.
fixture Fig. 2
Leveling foot Fig. 1

14
START-UP OF UNIT
Use the following procedure to start trial operation or actual operation of the unit.
1. Check the power switch is off, battery switch is off and sub-heater switch is off.
2. Connect the power supply cord to the dedicated outlet with appropriate rating. Then turn on the
power switch.
3. Turn on the battery switch.
Note:
The battery needs to be replaced about every 3 years. Contact Our sales representative or agent for
battery replacement.
4. The alarm buzzer sometimes operates. In this case, stop the buzzer by pressing the alarm buzzer
stop key (BUZZER).
5. Set the chamber temperature to the desired temperature.
6. Allow the chamber temperature to fall to the desired temperature. Check the chamber temperature
on the digital temperature indicator.
7. Press the alarm test key (ALARM TEST) and check that the alarm lamp blinks and alarm buzzer
activates.
8. Begin slowly placing items into the chamber to minimize the temperature rise.
CAUTION
Do not put too many warm articles into a freezer compartment before enough operating. Put items in a
few at a time after the freezer compartment temperature has cooled to at least -20oC.
Start-up of unit:
The unit is programmed to repeatedly turn the compressor on and off in order to make its startability
better when you start the unit at low ambient temperature (about 25oC or lower). However, the unit
would start the operation without turning the compressor on and off repeatedly when you install the
cooled unit at high ambient temperature and it causes the unit would have the starting current running
with longer time.
The unit should be exposed to ambient temperature sufficiently, 4 hours at least to avoid the breaker from
trapping.
Operation after power failure
The memory (chamber temperature setting and alarm temperature setting) is backed-up by nonvolatile
memory. Accordingly, the freezer resumes the operation with setting before power failure.
CAUTION
The start-up after power failure is subject to adverse affection such as voltage drop because all electrical
appliance start to operate simultaneously. Always check the running status.

15
CHAMBER TEMPERATURE SETTING
Table 1 shows the basic procedure for setting the chamber temperature. Perform key operations in the
sequence indicated in the table. The example in the table is based on the assumption that the desired
temperature is -25
oC. The chamber temperature is set to -40 oC at the factory.
Table 1 Basic operation sequence (Example: Chamber temperature -25
oC)
Description of operation Key operated Indication after operation
1 Turn the power switch on. ---- The current chamber temperature is
displayed.
2 Press set key. SET The second digit is flashed.
3 Set to -25 with the digit shift key
and the numerical value shift key.
When pressed, the settable digit is
shifted.
When pressed, the figure of settable
digit changes.
4 Press set key. SET
Set temperature is memorized and the
current chamber temperature is
displayed.
Note:
■Although the value of the chamber temperature setting can range from -15 oC to -44 oC, the
guaranteed temperature is -40 oC when there is no load at the ambient temperature at 35 oC.
■The temperature set mode returns to the temperature display mode automatically when 90 seconds
has passed without any key operation.
KEY LOCK FUNCTION
This unit is provided with the key lock function. When the key lock is ON, change of the setting through
the key pad is not available. The key lock is set in OFF at the factory.
Display Mode Function
L 0 Key lock is OFF Enable to change of the setting
L 1 Key lock is ON Disable to change of the setting
Table 2 Procedure for key lock setting (change from key lock OFF to key lock ON)
Description of operation Key operated Indication after operation
1 Press digit shift key for 5 seconds.
The first digit is flashed.
2 Press numerical value shift key and
scroll the figure to 1.
When pressed, the figure of settable
digit changes.
3 Press set key. SET The key lock is set to ON.
The current chamber temperature is displayed.
■The key lock works for the chamber temperature setting and function mode.
■To release the key lock, select L0 when performing the key lock mode operation described above.
■The key lock set mode returns to the temperature display mode automatically when 90 seconds has
passed without any key operation.

16
FUNCTION MODE
This unit has the following function mode.
Indication Mode Settable range
F01 Setting of high temperature alarm Between +5 oC and 20 oC higher than the
chamber set temperature (1oC gradient)
F02 Setting of low temperature alarm Between -5 oC and -20 oC lower than the
chamber set temperature (1 oC gradient)
F04 Setting of delay time of door alarm Between 1 and 15 minutes
(1 minute gradient)
F05 Setting of compressor delay time (for low
stage side only)
Between 3 and 15 minutes
(1 minute gradient)
F25 Setting of alarm resume time 000 or between 10 and 60 minutes
(10-minute gradient)
F50 Setting of alarm delay time Between 0 and 15 minutes
(1 minute gradient)
SETTING OF ALARM DELAY TIME
The delay time of the buzzer and remote alarm for high and low temperature alarm can be set between 0
and 15 minutes. The procedure in table 3 shows the sequence to set the delay time to 10 minutes.
The delay time is set to 15 minutes at the factory.
Table 3 Setting procedure for alarm delay time (change from 15 minutes to 10 minutes)
Description of operation Key operated Indication after operation
1 ---- The current chamber temperature is
displayed.
2 Press numerical value shift key for
5 seconds.
The first digit is flashed.
3
Scroll the figure to F50 by using
digit shift key and numerical value
shift key
When pressed, the figure of settable
digit changes.
When pressed, the changeable digit
moves.
4 Press set key. SET The current delay time is displayed.
The first digit is flashed.
5 Set the figure to 010 with the
numerical value shift key.
When pressed, the figure of the first
digit changes.
6 Press set key. SET
The delay time is memorized and
the current chamber temperature is
displayed.
■The alarm delay time set mode returns to the temperature display mode automatically when 90
seconds has passed without any key operation.

17
SETTING OF TEMPERATURE ALARM
This unit is provided with the high and low temperature alarm and the temperature at which the alarm is
activated is changeable.
The following procedure shows the setting of alarm temperature according to the condition below:
High temperature alarm: activates at the temperature +10 oC higher than the set temperature
Low temperature alarm: activates at the temperature -10 oC lower than the set temperature
Note:
The alarm temperature is set at the factory +15 oC higher and lower than the set temperature.
The available range of alarm temperature is between +5 oC and +20 oC higher or lower than the set
temperature.
Table 4. Procedure for setting high temperature alarm (Change from +15 oC to +10 oC)
Description of operation Key operated Indication after operation
1 ---- The current chamber temperature is
displayed.
2 Press numerical value shift key for
about 5 seconds. The first digit is flashed.
3 Press numerical value shift key
and scroll the figure to 1.
When pressed, the figure of settable
digit change.
4 Press set key. SET The current setting is displayed and
the first digit is flashed.
5 Scroll the figure to 010 by using the
numerical value shift key
When pressed, the figure of settable
digit changes.
6 Press set key. SET
Alarm temperature is memorized and
the current chamber temperature is
displayed.
Table 5. Procedure for setting low temperature alarm (Change from -15 oC to -10 oC)
Description of operation Key operated Indication after operation
1 ---- The current chamber temperature is
displayed.
2 Press numerical value shift key for
about 5 seconds. The first digit is flashed.
3 Press numerical value shift key
and scroll the figure to 2. When pressed, the figure of settable digit change.
4 Press set key. SET The current setting is displayed and
the first digit is flashed.
5 Scroll the figure to -10 by using the
numerical value shift key
When pressed, the figure of settable
digit changes.
6 Press set key. SET
Alarm temperature is memorized and
the current chamber temperature is
displayed.
■The alarm temperature set mode returns to the temperature display mode automatically when 90
seconds has passed without any key operation.

18
SETTING OF ALARM RESUME TIME
The alarm buzzer is silenced by pressing alarm buzzer stop key (BUZZER) on the control panel during
alarm condition.(The remote alarm sound and lamp are not silenced.)
The buzzer will be activated again after certain suspension if the alarm condition is continued. The
suspension time can be set by following the procedure shown in the Table 6 below.
The example in the table is based on the assumption that the desired duration is 20 minutes. The
duration is set to 30 minutes at the factory.
Table 6 Setting procedure for alarm resume time (change from 30 minutes to 20 minutes)
Description of operation Key operated Indication after operation
1 ---- The current chamber temperature is
displayed.
2 Press numerical value shift key for
5 seconds. The first digit is flashed.
3
Set the figure to F25 with the
numerical value shift key and the
digit shift key.
When pressed, the figure of settable
digit changes.
The settable digit is shifted.
4 Press set key. SET The current setting is displayed.
The second digit is flashed.
5 Scroll the figure to 020 with the
numerical value shift key.
When pressed, the figure of settable
digit changes.
6 Press set key. SET
The setting is memorized and
the current chamber temperature is
displayed.
■The settable alarm resume time is 10, 20, 30, 40, 50, or 60 minutes (The setting is 010, 020, 030, 040,
050, or 060). The buzzer would not resume if the resume time is set in 000.
■It is recommended to set the alarm resume time when the freezer is not under alarm condition. The
setting during alarm condition is effective on the next alarm condition.
■The alarm resume time set mode returns to the temperature display mode automatically when 90
seconds has passed without any key operation.
■The setting of alarm resume time is invalid when the delay time for high and low temperature alarm is
set to 0.