Phcbi MDF-U76V User manual

MDF-U76V
Please read the operating instructions carefully before using this product, and keep the operating
instructions for future use.
See page 39 for model number.㻌

Operating Instructions
Ultra-Low Temperature Freezer

1
CONTENTS
INTRODUCTION P. 2
PRECAUTIONS FOR SAFE OPERATION P. 3
ENVIRONMENTAL CONDITIONS P. 7
FREEZER COMPONENTS P. 8
Control panel P.10
REMOTE ALARM TERMINAL P. 11
AIR INTAKE PORT P. 11
INSTALLATION SITE P. 12
INSTALLATION P. 13
START-UP OF UNIT P. 14
CHAMBER TEMPERATURE SETTING P. 15
KEY LOCK FUNCTION P. 15
ALARM TEMPERATURE SETTING P. 16
SETTING OF ALARM RESUME TIME P. 17
MONITOR OF FREEZER STATUS P. 18
SETTING OF COMPRESSOR DELAY TIME P. 19
SETTING OF DOOR ALARM DELAY TIME P. 20
ALARMS & SAFETY FUNCTIONS P. 21
ROUTINE MAINTENANCE
Cleaning of cabinet P. 22
Cleaning of condenser filter P. 22
Defrosting of inside wall P. 23
Cleaning of air intake port P. 24
REPLACEMENT OF WEAR-OUT PARTS P. 25
Replacement of battery for power failure alarm P. 25
Replacement of fan motor P. 25
TROUBLESHOOTING P. 26
DISPOSAL OF UNIT P. 27
Recycle of battery P. 27
Fluorinated greenhouse gas P. 27
Decontamination of unit P. 27
TEMPERATURE RECORDER (OPTION) P. 32
Setting of MTR-G85C P. 32
BACKUP COOLING KIT (OPTION) P. 34
SMALL INNER DOOR (OPTION) P. 36
INVENTORY RACK (OPTION) P. 37
SPECIFICATIONS P. 38
PERFORMANCE P. 39
SAFETY CHECK SHEET P. 40

2
INTRODUCTION
ŶRead the operating instructions carefully before using the appliance and follow the instructions for
safety operation.
ŶPHC Corporation never guarantees any safety if the appliance is used for any objects other than
intended use or used by any procedures other than those mentioned in the operating instructions.
ŶKeep the operating instructions in an adequate place to refer to it as necessary.
ŶThe contents of the operating instructions will be subjected to change without notice due to the
improvement of performance or functions.
ŶContact our sales representative or agent if any page of the operating instructions is lost or page order
is incorrect.
ŶContact our sales representative or agent if any point in the operating instructions is unclear or if there
are any inaccuracies.
ŶNo part of the operating instructions may be reproduced in any form without the expressed 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.
<Intended Use>
This equipment is designed for low temperature storage of biomedical samples.

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;
㻌This symbol means caution.
㻌This symbol means an action is prohibited.
㻌This symbol means an instruction must be followed.
Be sure to keep the operating instructions in a place accessible to users of this unit.
< Label on the unit >
This mark is labeled on the cover in which the electrical components of high voltage are
enclosed to prevent the electric shock.
The cover should be removed by a qualified engineer or service personnel only.
WARNING
As with any equipment that uses CO2gas, there is a likelihood of oxygen depletion in the vicinity
of the equipment. It is important that you assess the work site to ensure there is suitable and
sufficient ventilation. If restricted ventilation is suspected, then other methods of ensuring a
safe environment must be considered. These may include atmosphere monitoring and warning
devices.

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.
Before proceeding with maintenance or checking the unit, set the power switch to OFF, and
disconnect the power supply plug. Performing the work while power is still flowing to the product
or while the power supply plug is still connected may give rise to electric shock and/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 power supply cord or plug may cause fire or electric shock.
Do not use the power supply cord if its plug is loose. Such power 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 power supply 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 are locked completely with a key.
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 place this unit in a location where it is difficult to disconnect the power supply plug.
Failure to disconnect the power supply plug may cause fire in the event of a problem or malfunction.
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 (copy the last page) when you request any repair or maintenance for
the safety of service personnel.
CAUTION

7
ENVIRONMENTAL CONDITIONS
This equipment is designed to be safe at least under the following conditions (based on the IEC
61010-1):
ŶIndoor use;
ŶAltitude up to 2000 m;
ŶAmbient temperature 5 oC to 40 oC;
ŶMaximum relative humidity 80 % for temperature up to 31 oC decreasing linearly to 50 % relative
humidity at 40 oC;
ŶMains supply voltage fluctuations up to ±10 % of the nominal voltage;
ŶTransient overvoltages up to the levels of OVERVOLTAGE CATEGORY II;
ŶTemporary OVERVOLTAGES occurring on the mains supply;
ŶApplicable pollution degree of the intended environment (POLUTION DEGREE 2 in most cases);

8
FREEZER COMPONENTS
11(inside)
7
1
2
3
6
8
12
7
4
9
10
13
5
17
18
16
14
19
15
Rear side
Power supply cord
Shelf

9
FREEZER COMPONENTS
1. Control panel (on the upper front of the outer door): The current chamber temperature or set
temperature is displayed. See page 10 for details.
2. Outer door: To open the door, grip the handle. When closing, lock the outer door latch completely.
3. Inner door: The operation of the inner door should be quick to minimize the temperature rise in
chamber. Lock the inner door latch completely when the inner door is closed. The inner door is
removable for cleaning or defrosting. See page 23 “ROUTINE MAINTENANCE”.
4. Outer door latch: Always lock the latch when the outer door is closed.
5. Inner door latch: Always lock the inner door latch when the inner door is closed.
6. Magnetic door gasket: This provides a tight door seal and prevents cold air leak. Keep clean.
7. Access port (rear and bottom): This is used for leading a cable and sensor of a measuring
equipment, or nozzle of backup cooling kit to chamber.
Replace the cap and insulation after using the access port. Improper replacement may cause poor
cooling or condensation around the outside of access port.
8. Air intake vent (grille): Do not block this vent to keep the proper cooling performance.
9. Caster: Four casters are provided to facilitate moving of the cabinet. For the installation, adjust the
leveling foot so that the front two casters cannot contact with the floor.
10. 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.
11. Condenser filter (behind the grille): This filter prevents the dust from accumulating on the
condenser. The dusty condenser filter may cause failure of refrigerating device. Clean the condenser
filter once a month. See page 22 “ROUTINE MAINTENANCE” for the cleaning.
12. Space for temperature recorder: A temperature recorder (optional component) can be attached
here. See page 32“ TEMPERATURE RECORDER (OPTION)”.
13. Key lock: Turn counterclockwise to 180 owith a key and the outer door is securely locked.
14. Air intake port: After closing the outer door, if used to open soon. See page 11
15. Fixture (on back side): Two fixtures are provided as spacers between the cabinet and wall and
also serve as hooks to fix the unit. See page 13 “INSTALLATION”.
16. Power switch: This is for turning ON/OFF the power to the unit. ON – “I” OFF – “ż”
17. Remote alarm terminal: This is used to notice an alarm condition of the unit to remote location.
Refer to page 11 “REMOTE ALARM TERMINAL”.
18. Battery switch: This is a switch for a battery for power failure alarm. Normally, turn on this switch.
Be sure to turn off this switch if the freezer is not in operating for the long period (over one month).
19. Fuse: AC 250 V, 5 A is attached.
WARNING
Fix the shelf stopper and shelves securely. Incomplete installation may cause injury or damage.
Never touch the storage items with wet hands. Touching with the wet hands may cause frostbite.

10
FREEZER COMPONENTS
Control panel
1. Digital temperature indicator: This indicator shows the present chamber temperature or set
temperature. And an error code and a chamber temperature are displayed alternately when the self
diagnostic function detects any abnormality. See page 21 for details.
2. Status monitor lamp (STATUS): This lamp lights when environmental condition or status gets
worse or the unit is out of normal operation.
3. Battery check lamp (BATTERY): This lamp lights to recommend the battery replacement. This
lamp blinks to recommend the fan motor replacement. For the replacement, contact our sales
representative or agent.
4. Door check lamp (DOOR): This lamp lights when the outer door is open.
5. Alarm lamp (ALARM): This lamp is flashed during alarm condition.
6. Filter check lamp (FILTER): This lamp lights and buzzer sound when the excessive dust is
accumulated on the condenser filter. When this lamp lights, clean the condenser filter following the
procedure on page 22.
7. 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 ,compressor delay time and door alarm delay time. Refer to page 15,
16,17,19 and 20 for details respectively.
8. 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 details.
9. Set key (SET): Temperature setting mode is led by pressing this key and the changeable digit is
flashed. By pressing this key again, the setting is memorized. The setting mode returns to the
temperature display mode automatically when 90 seconds has passed without any key operation.
10. Status key (STATUS): By pressing this key in the event of the status monitor lamp ON, the status
code is displayed on the digital temperature indicator. This key is not effective when the freezer is
running normally. See page 18 for details.
11. Alarm test key (ALARM TEST): To check the alarm system during 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.
12. Buzzer stop key (BUZZER): To silence the audible alarm under alarm condition, press this key.
The buzzer during alarm test cannot be silenced by this key. But the remote alarm is not canceled.
12
BATTERY
STATUS FILTER
A
LARM
DOOR
TEMPERATURE
(
oC
)
BUZZER ALARM
TEST STATUS SET
11 10 9 8 7
1 32 654

11
REMOTE ALARM TERMINAL
The terminal of the remote alarm is installed at the lower left side of the unit. The alarm is outputted
from this terminal. Contact capacity is DC 30 V, 2 A.
Contact output: between COM. and N.O. between COM. and N.C.
At normal Open Close
At abnormal Close Open
Note:
• The buzzer is silenced by pressing buzzer stop key (BUZZER) on the control panel during alarm
condition. (A remote alarm is continuing the operation.)
The buzzer will be activated again after certain suspension if the alarm condition is continued.
• The alarm is actuated when the power supply plug is disconnected from the outlet or the power switch is
OFF.
AIR INTAKE PORT
When the outer door is closed and opened soon, the outer door
sometimes does not open.
The warm air which went into the chamber is cooled down rapidly,
and this is because air inside the chamber contracted.
Follow the procedure below when the outer door is closed and
opened soon.
1. Turn the cap of the left side counterclockwise about two laps.
(Or remove the cap)
2. Allow about twenty seconds before open the outer door.
3.Close (or replace) the cap when the door operation is
completed.
The outer door may not open in the above method when there are frost and ice in the air intake port. In
that case, open the cap and check the frost inside the air intake port. Remove the frost inside the air
intake port with the enclosed “stick for air intake port cleaning” when the excessive frost is built in the air
intake port. Clean an air intake port every month even when there is no frost inside the air intake port.
Refer to page 24.
WARNING
For removing the frost of the air intake port, do not use a tool with sharp edge such as a knife or a screw
driver.
Replace the cap when the air intake port is not used. Improper replacement may cause rise of chamber
temperature or condensation around the air intake port.
Cap
Two laps
Use a twisted shielded wire for the connection.
Type UL2343, UL2448, UL2464, UL2552, UL 2623
Length: 30 m max.

12
INSTALLATION SITE
To operate this unit properly and to obtain maximum performance, install the unit in a location with the
following conditions:
ŶA 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.
ŶA 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.
ŶA 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.
ŶA location with little temperature change
Install the unit under stable ambient temperature. The allowable ambient temperature is between +5oC
and +30 oC.
ŶA 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.
ŶA 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.
ŶA location without flammable or volatile 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.
ŶA 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. Fix the frame to the wall with these fixtures and rope
or chain. (Fig. 2)
4. Ground (earth)
The ground (earth) is for preventing the electric shock in the case of the electrical insulation is somehow
degraded. 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.
5. Installing the earth leakage breakers
This product is to connect an earth leakage breaker to the power supply side of the product.
Contact our sales representative or agent at the time of installation of the earth leakage breaker.
Fig. 2
Fig.1
Leveling foot Fixture

14
START-UP OF UNIT
Use the following procedure to start trial operation or actual operation of the unit.
1. Turn off the switch of the backup cooling kit (optional component) if it is installed.
2. Connect the power supply cord to the dedicated outlet having appropriate rating with the chamber
empty, and turn on the power switch on the freezer.
3. Turn on the battery switch.
4. Set the desired chamber temperature. See page 15 for the chamber temperature setting.
5. Check that the chamber temperature reaches the desired temperature.
6. Turn on the switch of backup cooling kit (optional component) if it is installed.
7. Make sure that the alarm lamp blinks and the buzzer sounds by pressing the alarm test key (ALARM
TEST). The remote alarm is also operated. E09 is displayed on the digital temperature indicator if the
battery switch is OFF. Make sure to turn on the battery switch.
8. After confirming the above, you can put articles into the chamber in a small batch to prevent the
temperature rise.
CAUTION
Do not put too many warm articles in the chamber. The temperature rise may cause the damage to
the articles in the chamber.
WARNING
Fix the shelf stopper and shelves securely. Incomplete installation may cause injury or damage.
Operation after power failure
The set value is memorized by nonvolatile memory. Accordingly, the freezer resumes the operation with
setting before power failure.
When the freezer is recovered from power failure with the chamber temperature higher than the preset
temperature, then the high temperature alarm is activated and the buzzer sounds and the remote alarm is
also activated. Push the buzzer stop key (BUZZER) to silence buzzer and take appropriate actions if
needed.
WARNING
When this product operates at the first start-up or after no use for long period, the built-in battery capacity
may be lowered or completely zero because of discharge of the battery. After installation the product,
the freezer should operate for more than 3 days (72 hours) to charge the battery.

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 -75 oC.
Note: The chamber temperature is set to -80 oC at the factory.
Table 1. Basic operation sequence (Example: Chamber temperature -75 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 -75 with the numerical value
shift key and digit shift key.
When pressed, the figure of settable
digit changes.
When pressed, the settable digit
is shifted.
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 -50 oC to -90 oC, the guaranteed
temperature when there is no load is -85 oC when the ambient temperature is 30 oC.
• The setting mode returns to the temperature display mode automatically when 90 seconds has passed
without any key operation. In this case, any setting before pressing set key (SET) is not memorized.
KEY LOCK FUNCTION
This unit is provided with the key lock function. When the key lock is ON, change of temperature 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 temperature setting
L 1 Key lock is ON Disable to change of temperature 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 ---- The current chamber temperature is
displayed.
2 Press digit shift key for 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 changes.
4 Press set key. SET The key lock is set to ON. The current chamber temperature is
displayed.
• The setting mode returns to the temperature display mode automatically when 90 seconds has passed
without any key operation. In this case, any setting before pressing set key (SET) is not memorized.

16
ALARM TEMPERATURE SETTING
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 5 oC higher than the set temperature
Low temperature alarm: activates at the temperature 5 oC lower than the set temperature
Note:
The alarm temperature is set at the factory 10 oC higher and lower than the set temperature.
The available range of alarm temperature is between 5 oC and 40 oC higher or lower than the set
temperature.
Table 3. Procedure for setting high temperature alarm
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 changes.
4 Press set key. SET The current setting is displayed and
the first digit is flashed.
5 Scroll the figure to 005 by using digit shift key and numerical value
shift key
When pressed, the figure of settable digit changes.
When pressed, the changeable digit
is shifted.
6 Press set key. SET Alarm temperature is memorized and the current chamber temperature is
displayed.
Table 4. Procedure for setting low temperature alarm
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 changes.
4 Press set key. SET The current setting is displayed and
the first digit is flashed.
5 Scroll the figure to -05 by using digit shift key and numerical value
shift key
When pressed, the figure of settable digit changes.
When pressed, the changeable digit
is shifted.
6 Press set key. SET Alarm temperature is memorized and the current chamber temperature is
displayed.
• The setting mode returns to the temperature display mode automatically when 90 seconds has passed
without any key operation. In this case, any setting before pressing set key (SET) is not memorized.

17
SETTING OF ALARM RESUME TIME
The buzzer is silenced by pressing buzzer stop key (BUZZER) on the control panel during alarm
condition. (The remote alarm is not stopped).
However, if the alarm condition is continued after the “alarm resume time” has passed, the buzzer sounds
again. It is possible to change the alarm resume time by the procedure shown in the Table 5.
The example in the table is based on the assumption that the desired duration is 20 minutes.
Note: Factory setting; 30 minutes.
Table 5. 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 digit shift key for 5 seconds.
The first digit is flashed.
3 Set the figure to F25 with the digit shift key and numerical value shift
key.
The settable digit is shifted.
When pressed, the figure of settable
digit changes.
4 Press set key. SET The current resume time is displayed.
The second digit is flashed.
5 Set 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 setting cannot be changed during power failure.
• The setting mode returns to the temperature display mode automatically when 90 seconds has passed
without any key operation. In this case, any setting before pressing set key (SET) is not memorized.

18
MONITOR OF FREEZER STATUS
The freezer has a function to monitor the running status of the unit as shown in table 6 below. This is to
notice the running status getting worse (not failure).
1. The status monitor lamp is lit when one of the running status shown in table 6 is detected.
2. The S code (--X, X: 1 to 3) is displayed on the temperature indicator by pressing status key (STATUS)
when the status monitor is lit.
3. Pressing the status key (STATUS) again returns to current chamber temperature on the temperature
indicator. (The indication returns to the chamber temperature display automatically when no key is
operated for 90 seconds.)
Table 6. Monitor of running status
Kind of
function Status Indication
If this status
continues Remedy
Notice of
abnormal
ambient
temperature
When the ambient
temp. is over㻌35 oC
or lower than 0 oC.
status lamp
lights.
“--1” is displayed.
Decrease of cooling
performance or
durability of
refrigerating circuit.
Recheck air-
conditioning of
installed site.
Notice of low
voltage
When the power
source voltage is
less than 195 V
when the rated㻌
voltage is between㻌
220 V and 240 V.
status lamp
lights.
“--2” is displayed.
Abnormal heat at
power supply outlet
or degrade of
starting performance
of refrigerating
circuit
Use dedicated
power source.
Notice of
overload
condition
When the running
rate of refrigerating
Circuit is higher than
usual.
status lamp
lights.
“--3” is displayed.
Decrease of cooling
performance or
durability of
refrigerating circuit.
1. This is likely to
happen when a
large amount of
materials is stored.
2. Check ambient
temp., voltage, and
sealing of
outer/inner door.
Note:
• The S code displayed on the temperature indicator is changed every few seconds if two or three status
shown in the above table are detected at the same time. (--1 ĺ--2 ĺ--3 ĺ--1 repeated)
• The monitoring function does not trigger a buzzer or conduct a safety operation.
• In the case of multiple indication of S code, follow the remedy for each status.
• The status monitor lamp (STATUS) may be lit under normal running condition when the small inner door
(MDF-7ID) is installed because of less cooling performance. In this case, adjust the air conditioning so
that the ambient temperature is around 23 oC, or set the chamber temperature 10 oC higher than the
current setting.