Sanyo MDF-594 User manual

MDF-594
MDF-594AT
MDF-794
MDF-794AT
Ultra Low Temperature Freezer
INSTRUCTION MANUAL
MDF-594AT

1
CONTENTS
INTRODUCTION P.2
PRECAUTIONS FOR SAFE OPERATION P. 3
ENVIRONMENTAL CONDITIONS P. 7
FREEZER COMPONENTS P. 8
Control panel P. 10
INSTALLATION SITE P. 11
INSTALLATION P. 12
START-UP OF UNIT P. 13
CHAMBER TEMPERATURE SETTING P. 14
ALARM TEMPERATURE SETTING P. 15
SETTING OF ALARM RESUME TIME P. 16
REMOTE ALARM TERMINAL P. 17
ALARMS AND SAFETY FUNCTIONS P. 17
TEMPERATURE RECORDER (AT type) P. 19
BACK-UP SYSTEM (AT type) P. 21
ROUTINE MAINTENANCE
Cleaning of cabinet P. 22
Cleaning of condenser filter P. 22
Defrosting of inside wall P. 22
TROUBLESHOOTING P. 23
REPLACEMENT OF BATTERY P. 24
DISPOSAL OF UNIT P. 25
Recycle of battery P. 25
SPECIFICATIONS P. 30
PERFORMANCE P. 32
SAFETY CHECK SHEET P. 33

2
INTRODUCTION
■Read this manual carefully before using the appliance and follow the instructions for safety operation.
■Sanyo never guarantee any safety if the appliance is used for any objects other than intended use or
used by any procedures other than those mentioned in this manual.
■Keep this manual in an adequate place to refer to it as necessary.
■The contents of the manual will be subjected to change without notice due to the improvement of
performance or functions.
■Contact Sanyo sales representative or agent if any page of the manual is lost or page order is incorrect.
■Contact Sanyo sales representative or agent if any point in this manual is unclear or if there are any
inaccuracies.
■No part of this manual may be reproduced in any form without the expressed written permission of
Sanyo.

3
PRECAUTIONS FOR SAFE OPERATION
It is imperative that the user complies with this manual 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;
this symbol means caution.
this symbol means an action is prohibited.
this symbol means an instruction must be followed.
Be sure to keep this manual 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 a 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.
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
cord. A damaged cord may cause electric shock or fire.
Disconnect the power 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.
WARNING

6
PRECAUTIONS FOR SAFE OPERATION
Use a dedicated power source (a dedicated circuit with a breaker) as indicated on the rating label
attached to the unit. A branched circuit 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
ENVIRONMENTAL CONDITIONS
This equipment is designed to be safe at least under the following conditions (based on the IEC-1010-1):
■Indoor use;
■Altitude up to 2000 m;
■Ambient temperature 5oC to 40oC
■Maximum relative humidity 80% for temperature up to 31oC decreasing linearly to 50% relative humidity
at 40oC;
■Mains supply voltage fluctuations not to exceed ±10% of the nominal voltage;
■Other supply voltage fluctuations as stated by the manufacturer;
■Transient overvoltages according to Installation Categories (Overvoltage Categories) II; For mains
supply the minimum and normal category is II;
■Pollution degree 2 in accordance with IEC 664.

8
FREEZER COMPONENTS
MDF-594
1
3
13
7
8
12
11
10
4
2
9
6
5
15
14

9
FREEZER COMPONENTS
1. Lock
2. Door: Hinged type. The door can be opened in any angle on the way to full open.
3. Magnetic door gasket: Seals the door and prevents leakage of cold air.
4. Inner lid: Serves as a means of reducing cold air leakage when the door is open. Remove the frost
before it is accumulated too much.
5. Access port: Serves a means of leading the measuring cable from the freezing room to the outside.
6. Caster: 4 casters are provided. They make the moving of the unit easier.
7. Leveling foot: Serves to adjust the height and to settle the frame.
8. Temperature display area: The digital temperature indicator, alarm lamp, and filter check lamp are
installed.
9. Exhaust air vent: Be careful not to block this.
10. Control panel cover
11. Control panel cover lock: To lock the control panel cover to avoid the setting by accidental
contact.
12. Control panel: Temperature set key, power switch and so on are installed. AT type has a
temperature recorder and switches of back-up system. Refer to page 10 for details.
13. Back-up system joint (rear side): It is positioned at rear of the unit. Serves to connect with the
pipelines from the liquid CO2cylinder.
14. Side panel: For cleaning the condenser filter and condenser. The remote alarm terminal is located
inside the panel.
15. Air intake vent (grille): Do not block this vent to keep the proper cooling performance.

10
●
FREEZER COMPONENTS
Control panel
1. Power switch (POWER): Power all functions except remote alarm and back-up system for AT type.
2. CO2Back-up switch (CO2BACK UP): AT type only.
3. CO2Back-up test switch (TEST): AT type only.
4. Battery switch: It is the switch of the battery for the power failure alarm. Turn it on usually. Turn
it off when you do not drive for a long time. (More than 1 month).
5. Mode setting key. (PV/SV): This key has functions.
PV: Present freezer compartment temperature is displayed.
SV: Setting temperature is displayed. When the desired temperature is set, this key should be
pressed (SV side). The temperature setting can be done by using (6),(7),(8), keys, initial setting
temperature is -80oC.
6. Digit shift key ( ): The digit of the figure displayed for temperature adjustment can be shifted
using this key.
7. Numerical value shift key ( ): The figure that is displayed digitally can be changed by pressing
this key.
8. Enter key (ENT): When the desired temperature is reached, press this key. Operation will
commence toward this new point.
9. Alarm test key (ALARM): Check that the alarm lamp and the buzzer are functional when the
freezer is operating well.
10. Alarm buzzer stop key (BUZZER): To stop the alarm from sounding, press this key. Should a
further abnormality occur, the buzzer will sound automatically.
11. Alarm lamp (ALARM) and buzzer: They operate in the following cases:
a) Break down or power failure at the power supply.
- Alarm lamp blinks, buzzer sounds.
b) Temperature rises about 10oC higher than the setting temperature.
- Alarm lamp blinks, buzzer sounds about 12 minutes later.
12. Filter check lamp (FILTER CHECK): This lamp brinks and buzzer sound when the condenser
filter is clogged. Clean the condenser filter according to page 22 “Cleaning of condenser filter”.
8
12 3 4
1
0
7
6
9
5
12 11
MDF-594AT/ 794AT

11
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 and
+35oC.
■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 flammable or volatile location. 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.

12
INSTALLATION
1. Remove 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.
2. Adjusting the leveling foot
Extend the leveling feet by rotating them
counterclockwise to contact them to the floor.
Ensure the unit is level.
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.
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.
MDF-594
Leveling foot

13
START-UP OF UNIT
Follow the procedures for the initial and consequent operations of the unit.

1. Make sure that all the switches on the control panel, such as the power switch, battery switch, the
back-up system switch (AT type only) are off.
2. Liquid CO2gas cylinder for AT type is set at this time.
3. Shut the door and connect the power cable to the power supply after the inner lid is installed.
4. Turn on the power supply switch, battery switch and the temperature is displayed on the digital
indicator.
5. Set the desired chamber temperature by using the keypads on the control panel. Do not set the
chamber temperature at lower than -86oC.
6. Set the temperature at which the back-up system activates according to the procedure on page 19
when the temperature display pointer of temperature recorder corresponds with the desired temperature if
the back-up system is used. (AT type only)
7. Switch on the remote alarm switch and CO2back-up switch (AT type only).
8. Check that the alarm lamp lights and the buzzer sound by pressing the alarm test key.
9. Make sure that liquid CO2spouts into the chamber by pushing the CO2back-up test switch.
10. Now you can put articles into the freezer chamber. Switch off the remote alarm switch and the CO2
back-up switch (AT type only) temporarily when putting in a lot of warm articles. Switch on these
switches again after a certain period of operation.
Operation after power failure
The set value is memorized by nonvolatile memory in the event of power failure. Accordingly, the
freezer resumes the operation with setting before power failure.

14
CHAMBER TEMPERATURE SETTING
Table 1 shows the basic operation method. Perform key operations in the sequence indicated in the
table. The example in the table is based on the assumption that the temperature is -75oC.
Note: The unit is set at the factory that the chamber temperature is -80oC.
Table 1. Basic operation sequence (Example: Chamber temperature -75oC)
Description of operation Key operated Indication after operation
1 Turn on the power switch. ----- The current chamber temperature is
displayed.
2
Press mode setting key when
changing the set temperature
during operation.
PV/SV The second digits blinks.
3 Set the second digit to 7 with the
numerical value shift key.
When pressed, the figure of settable
digit changes.
4 By pressing the digit shift key, set
the first digit. The first digit blinks.
5 Set the first digit to 5 with the
numerical value shift key.
When pressed, the figure of settable
digit changes.
6 Press enter key. ENT
Set temperature is memorized and
the current chamber temperature
is displayed.
Note: The temperature set mode returns to the temperature display mode automatically when 90
seconds has passed without any key operation.

15
ALARM TEMPERATURE SETTING
This unit is provided with the high temperature alarm. The setting of high temperature alarm is 10oC or
15oC (The setting value is 2 kinds.) higher than the setting of chamber temperature. The procedure in
table 2 shows the sequence to set the high temperature alarm at 15oC higher than the setting of chamber
temperature. Set the figure to 000 at step 5 when setting the high temperature alarm at 10oC higher
than the setting of chamber temperature.
Note:
The alarm temperature is set at the factory 10oC higher than the setting of chamber temperature.
Table 2. High temperature alarm setting (15oC higher than the setting of chamber temperature)
Description of operation Key operated Indication after operation
1 ----- The current chamber temperature is
displayed.
2 Press the numerical value shift key
for about 5 seconds. The first digit blinks.
3 Set the first digit to 1 with the
numerical value shift key. The first digit blinks.
4 Press enter key. ENT The first digit blinks.
5 Set the first digit to 1 with the
numerical value shift key. When pressed, the figure of settable digit changes.
6 Press enter key. ENT
Alarm temperature is memorized and
the current chamber temperature
is displayed.
Note: The setting is not memorized if the mode setting key (PV/SV) is pressed during alarm
temperature setting. The chamber temperature is displayed for 3 seconds when the numerical value
shift key is pressed 5 times for 5 seconds.

16
SETTING OF ALARM RESUME TIME
The alarm buzzer is silenced by pressing alarm buzzer stop key (BUZZER) on the control panel during
alarm.
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 3 below.
The example in the table is based on the assumption that the desired duration is 20 minutes.
Note: The duration is set in 30 minutes (initial setting 130) at the factory.
Table 3. Setting procedure (change from 30 minutes to 20 minutes)
Description of operation Key operated Indication after operation
1 ----- The current chamber temperature is
displayed.
2 Press the numerical value shift key
for about 5 seconds.
The first digit blinks.
3 Set 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 enter key. ENT The current setting is displayed
and the first digit blinks.
5 Set to 120 with the digit shift key
and numerical value shift key.
The settable digit is shifted.
When pressed, the figure of settable
digit changes.
6 Press enter key. ENT
Alarm resume time is memorized
and the current chamber
temperature is displayed.
• The settable alarm resume time is between 10 and 60 minutes with 1 minute increment. (The setting is
110, 111, ------- 159, 160). The buzzer would not sound if the resume time is set in 100.
• The buzzer is ON when the resume time is changed in F25 while the resume time is counted (the
buzzer is silenced by alarm buzzer stop key (BUZZER)). The count of resume time is stopped.
• The setting cannot be changed during power failure.
• The set mode returns to the temperature display mode automatically when about 90 seconds has
passed without any key operation. In this case, any setting before pressing enter key (ENT) is not
memorized.
• It is selectable whether the buzzer is in conjunction with the remote alarm or not when the buzzer is
silenced by alarm buzzer stop key (BUZZER). (The remote alarm is not in conjunction with the buzzer
by factory setting.)
• The remote alarm is activated in conjunction with the buzzer if the third digit “1” is set to “0” in the step 5
above

17
REMOTE ALARM TERMINAL
The terminal of the remote alarm is located at rear of the machinery room, upper side of the electric box.
The signal is contact output. The recommended contact capacity is 2 A (DC 30 V) .
a) Contact output : normal open connect with N.O. and COM.
b) Contact output : normal close connect with N.C. and COM.
Consult our dealer or our office for installation of the remote alarm.
Operation after power failure
The set value (setting of chamber temperature and alarm temperature) is memorized by nonvolatile
memory. Accordingly, the freezer resumes the operation with setting before power failure.
ALARMS AND SAFETY FUNCTIONS
This unit has the alarm and safety functions shown in table below, and also self diagnostic function.
Table 4. Alarm and safety function
Alarm & safety Situation Indication Buzzer Safety operation
High temperature
alarm
When the chamber temp. is
approx. 10oC (or 15oC) higher
than the set temp.
Alarm lamp blinks.
Intermittent
tone with
about 12
min. delay.
Remote alarm
with 12 min. delay.
Power failure
alarm
At power failure
When power cord is
disconnected.
Alarm lamp blinks. Intermittent
tone. Remote alarm.
Filter check When the condenser filter
is clogged. Filter check lamp blinks. Intermittent tone. -----
Auto-return
When there is no key
pressing in each setting
mode for about 90 seconds.
Chamber temp. is
displayed. ----- Finishing of each setting mode.

18
ALARMS AND SAFETY FUNCTIONS
Table 4. Alarm and safety function
Alarm & safety Situation Indication Buzzer Safety operation
Sensor
abnormality
If the thermal sensor is
disconnected.
Alarm lamp blinks.
E01 and 50oC is
displayed alternately. Intermittent
tone
Remote alarm
Continuous
operation
If the thermal sensor is
shirt-circuited.
Alarm lamp blinks.
E02 and -170oC are
displayed alternately.
If the cascade sensor is
disconnected.
Alarm lamp blinks.
E03 and chamber temp.
are displayed alternately. Intermittent
tone Remote alarm
If the cascade sensor is
shirt-circuited.
Alarm lamp blinks.
E04 and chamber temp.
are displayed alternately.
If the filter sensor is
disconnected.
Alarm lamp blinks.
E05 and chamber temp.
are displayed alternately. Intermittent
tone Remote alarm
If the filter sensor is
short-circuited.
Alarm lamp blinks.
E06 and chamber temp.
are displayed alternately.
If the ambient temperature
sensor is disconnected.
ALARM lamp blinks.
E07 and chamber temp.
are displayed alternately. Intermittent
tone Remote alarm
If the ambient temperature
sensor is short-circuited.
ALARM lamp blinks.
E08 and chamber temp.
are displayed alternately.
Condenser temp.
abnormality
In the event of failure of fan
motor for cooling the
compressor
E10 and chamber temp.
are displayed alternately.
Intermittent
tone
Remote alarm.
Compressor of high
stage side stops.
Battery life
When it passed for about 3
years by ON the power
switch.
F1 and chamber temp.
are displayed alternately. ----- -----
Fan motor life
When it passed for about 6
years by ON the power
switch.
F2 and chamber temp.
are displayed alternately. ----- -----
Note：
•The filter check lamp sometimes blinks at the start-up under high ambient temperature. The lamp is off
when the chamber temperature is getting lower.
• Fan motors are expendable supplies. Exchange them for about every 6 years. Contact Sanyo sales
representative or agent at the time of replacement of the fan motor. (MDF-794 type has two fan motors.)
In the chamber, the explanation of the error alarm of the temperature control sensor
Indication Contents of a trouble
E01 When sensor lead wire (red) is opened.
E02
When sensor lead wire (red) is
short-circuited.
When sensor lead wire (white) or
(black) is opened.
RED BLACK WHITE

19
TEMPERATURE RECORDER (AT type)
The figure below shows the description of a temperature recorder. The temperature recorder is provided
with model AT type.
Feeding of chart
1. Open the door and let down the lever of the penholder; the pen point is apart from the chart. (Fig. 1)
2. Pull the cartridge out of the mounted position. (Fig. 2)
3. Set a new chart in place on the rear bottom of the cartridge. Set the hole on the chart in the cog of the
chart driving assembly and feed the chart in the direction of the arrow by driving the cog wheel.
4. Set the chart according to the mark of day and time. (Fig. 3)
5. When mounting, lay down the cartridge first, and push into the mounting position with the groove set a
the projection on the position.
6. Set up the cartridge and settle in position.
Replacement of cell
Replace the dry cell once a year as follows:
1. Put up the penholder first, then pull out cartridge from the
mounted position.
2. Reset the battery chamber cover with wire, on the bottom left
side, and take out the cell.
3. Set a new cell by turning its anode to this side.
4. Shut the cover after exchanging cells. Mount the cartridge
as before and lay down the penholder.
Note :
This temperature recorder is designed for the manganese dry
cell and the alkaline dry cell.
Do not use a rechargeable battery because the initial voltage of
such battery is low. The rechargeable battery may cause the
malfunction of recorder or shorten the battery life significantly.
Fig. 2 Fig. 3
Fig. 1
Cell
Recording indicator
Pen holder lever
Door
Warning indicator
Cartridge
Time Temperature