Service

SANYO Electric Biomedical Co., Ltd.

Manual Biomedical freezer
MDF-U333
MDF-U537
MDF-U537D

MDF-U537

ＳＭ７２１０１３９
Effective models

This service manual is effective following models.

Model name Model code Voltage and Frequency

MDF-U537 823 168 51 115V 60Hz
823 168 52 220V 50Hz
823 168 53 220V 60Hz
823 168 54 230V 50Hz
823 168 55 240V 50Hz
823 168 56 115V 60Hz
823 168 57 110V 60Hz
824 168 58 230V 50Hz
824 168 59 220V 50Hz
824 168 60 240V 50Hz
825 168 61
825 168 62

MDF-U537D 823 169 51 115V 60Hz

823 169 52 220V 50Hz
823 169 53 220V 60Hz
823 169 54 230V 50Hz
827 169 55 240V 50Hz
823 169 56 240V 50Hz
823 169 57 230V 50Hz
823 169 58 115V 60Hz
823 169 59 110V 60Hz
823 169 60 220V 50Hz
823 169 61
823 169 62

MDF-U333 823 170 51 115V 60Hz

823 170 52 220V 50Hz
823 170 53 220V 60Hz
823 170 54 230V 50Hz
823 170 55 240V 50Hz
823 170 56 110V 60Hz
823 170 57 230V 50Hz
823 170 58 240V 50Hz
823 170 59 220V 50Hz
823 170 60
823 170 61
823 170 62
 Contents

･Feature 1
･Specification MDF-Ｕ333 3
MDF-Ｕ537 5
MDF-Ｕ537D 7
･Dimensions MDF-Ｕ333 9
MDF-Ｕ537 10
MDF-Ｕ537D 11
･Refrigeration circuit 12
Refrigeration circuit principle diagram MDF-Ｕ333 15
Refrigeration circuit welding points MDF-Ｕ333 16
Refrigeration circuit principle diagram MDF-Ｕ537 17
Refrigeration circuit welding points MDF-Ｕ537 18
Refrigeration circuit principle diagram MDF-Ｕ537D 19
Refrigeration circuit welding points MDF-Ｕ537D 20
･Electrical Parts 21
･Specification of sensor 24
･Control specification 25
･W iring diagram 34
･Circuit diagram 37
･Components on P.C.B. 38
･Test data 39
･Parts loyout 49
･User’smanual 50
 Features
＜ＭＤＦ－Ｕ３３３＞

■ HFC refrigerant
Refrigerant circuit contains HFC refrigerant that effect to environment little.
Latest cooling system reduces negative factor to global environment. With ambient
temperature at 35℃, while temperature of inside chamber maintains -30℃.

■ PCM structure
PCM structure reduces amount of organic solvent.

■ Temperature control function

Unified temperature control range for same categories realized to set -20℃, which
is suitable for reagent preservation.

■ Specification unified
Unified specification for same categories, which also realized to unify performance for
high/low temperature alarm (SV is changeable in the range ±5～±15℃), power failure
alarm, remote alarm terminal, setting memorization by non-volatile memory.
Adopt new microprocessor system for display panel and keypad makes operation easily.

■ Self diagnosis function

Abnormal condition for temperature sensor is indicated by self-diagnosis system.

■ Validation
Control panel enables zero “0” adjust for validation.

■ New door latch mechanism

New door latch is adopted in order to close door surely for reagents.
It is also available to use individual lock mechanism.

■ Insulation wall thickness

Unit has necessary insulation performance for each temperature range.
Combination of PCM and frame form makes 610mm for frame size commonly.

■ Option
Internal temperature observation system is option.
Unit has communication function corresponding to it.
 Features
＜ＭＤＦ－Ｕ５３７，５３７Ｄ＞

■ HFC refrigerant
Refrigerant circuit contains HFC refrigerant that effect to environment little.
Latest cooling system reduces negative factor to global environment. With ambient
temperature at 35℃, while temperature of inside chamber maintains -30℃.

■ PCM structure
PCM structure reduces amount of organic solvent.

■ Temperature control function

New cooling system realizes to set -20℃, which is suitable for reagent preservation.

■ Specification unified
Unified specification for same categories, which also realized to unify performance for
high/low temperature alarm (SV is changeable in the range ±5～±15℃), power failure
alarm, remote alarm terminal, setting memorization by non-volatile memory.
Adopt new microprocessor system for display panel and keypad makes operation easily.

■ Self diagnosis function

Abnormal condition for temperature sensor is indicated by self-diagnosis system.

■ Validation
Control panel enables zero “0” adjust for validation.

■ New door latch mechanism

New door latch is adopted in order to close door surely for reagents.
It is also available to use individual lock mechanism.

■ Draw box for reagent preservation

100mm for depth of box makes things easily to arrange and take in & out.
(Adopted in bottom chamber of MDF-U537/U537D)

■ Compressor protection function

Sensor detects compressor’s warming up to control unit running.
 Specification

MDF-U333
Items Specification
Model description Biomedical freezer
Model Number MDF-U333
Outer dimension (Max) W 614 × D 733 × H 1620 mm
Inner dimension W 490 × D 485 × H 1290 mm
Effective chamber capacity 274 lit.
Exterior Zinc galvanized steel w/powder polyester coating (PCM)
Interior Polystyrene resin
Insulation Rigid polyurethane foam
Outer door 1 pc, Zinc galvanized steel w/powder polyester coating (PCM)
Latch 1 pc
Door lock 1 pc
(L) 4 pcs Inner dimension: W 446×D369×H220 mm
Basket
Accessories (S) 1 pc (for bottom column) Inner dimension: W 487×D221×H155mm
Others Defrosting spatula 1 pc, key 1 set, 4 card holders
Caster 4 pcs
Leveling legs 2 pcs (with caster)
Access hole φ 30mm. 1 place in left side.
Weights 81 Kg
Evaporator Tube on sheet type (function both evaporator and shelf)
Condenser Wire and tube type
Compressor Hermetic type 225W
HFC refrigerant
Refrigerant
R-134a
Cooling performance -30℃ (internal 1/2h air temperature, AT：35℃, no load)
Internal temperature control -20℃~-30℃
range (AT：5℃~35℃、no load)
Power supply Local voltage
MDF-U333
Items Specification
Microprocessor controlled system with non-volatilized memory.
Temperature controller
Temp. set range : -18℃～-40℃
Temperature sensor Thermistor
LED digital display (green colored) by 1℃.
Temperature display
Range : -50℃～50℃
Changeable SV±5℃～15℃. (Initial SV±10℃)
High/Low
ALARM lamp brinks and buzzer sounds intermittently
Temperature
(about 15 min. delay)
Remote alarm contact: turns ON during power failure alarm.
Alarm
ALARM lamp brinks, buzzer sounds intermittently, remote alarm
Power failure
contact turns ON during power failure alarm.
Remote alarm Remote alarm terminal 3P: contact capacity DC30v, Max2A, N.O.
contact –COM. (During power failure, temperature alarm: ON)
ALARM lamp
BUZZER: Buzzer key
ALARM TEST: Alarm test key
Control panel SET: To switch the SV and PV
Operation ＞: To shift the set digit
panel ∧: To change the SV
DEF: Defrost key
Power switch (Breaker switch)
Rear
Battery switch: Power failure alarm switch
Press ＞ key for five seconds
Key lock function
L0: Unlock L1: Lock
When each sensor is in fault,
Self diagnosis function Error code and internal temperature are displayed alternately.
Remote alarm contact turns ON with buzzer sounds.
Power switch Breaker switch
Compressor protection Overload relay
Chart recorder: MTR-G85
Option Mounting kit: MPR-S7(for bottom mounting)
: MDF-S740T(for top mounting)
 Specification

MDF-U537
Items Specification
Model description Biomedical freezer
Model Number MDF-U537
Outer dimension (Max) W 804 × D 772 × H 1802 mm
Inner dimension W 658 × D 607 × H 1272 mm
Effective chamber capacity 482 lit.
Exterior Zinc galvanized steel w/powder polyester coating (PCM)
Interior Polystyrene resin
Insulation Rigid polyurethane foam
Zinc galvanized steel w/powder polyester coating (PCM)
Outer door
2 pcs (upper and lower compartment)
Latch 2 pcs
Door lock 1 pc
(M) 6 pcs (upper compartment)
Inner dimension: W 290×D536×H136 mm
Basket
Accessories (S) 8 pcs (lower compartment)
Inner dimension: W 290×D536×H100mm
Others Defrosting spatula 1 pc, key 1 set, 14 card holders
Caster 4 pcs
Leveling legs 2 pcs (with caster)
Access hole φ 30mm. 1 place on rear.
Weights 131 Kg
Evaporator Tube on sheet type (function both evaporator and shelf)
Condenser Wire and tube type
Compressor Hermetic type 350W
HFC refrigerant
Refrigerant
R-407D
Cooling performance -30℃ (internal 1/2h air temperature, AT：35℃, no load)
Internal temperature control -20℃~-30℃
range (AT：5℃~35℃、no load)
Power supply Local voltage
MDF-U537
Items Specification
Microprocessor controlled system with non-volatilized memory.
Temperature controller
Temp. set range : -18℃～-40℃
Temperature sensor Thermistor 2P
LED digital display (green colored) by 1℃.
Temperature display
Range : -50℃～50℃
Changeable SV±5℃～15℃. (Initial SV±10℃)
High/Low
ALARM lamp brinks and buzzer sounds intermittently
Temperature
(about 15 min. delay)
Remote alarm contact: turns ON during power failure alarm.
Alarm
ALARM lamp brinks, buzzer sounds intermittently, remote alarm
Power failure
contact turns ON during power failure alarm.
Remote alarm Remote alarm terminal 3P: contact capacity DC30v, 2A, N.O. –COM.
contact (During power failure, temperature alarm: ON)
ALARM lamp
BUZZER: Buzzer key
ALARM TEST: Alarm test key
Control panel SET: To switch the SV and PV
Operation ＞: To shift the set digit
panel ∧: To change the SV
DEF: Defrost key
Power switch (Breaker switch)
Rear
Battery switch: Power failure alarm switch
Press ＞ key for five seconds
Key lock function
L0: Unlock L1: Lock
When each sensor is in fault,
Self diagnosis function Error code and internal temperature are displayed alternately.
Remote alarm contact turns ON with buzzer sounds.
Power switch Breaker switch
Overload relay
Detect temperature near compressor by thermistor sensor to control
Compressor protection compressor during overload.
Alarm: Error code and internal temperature are displayed alternately.
Remote alarm contact turns on with buzzer sounds.
Chart recorder: MTR-G85
Option Mounting kit: MPR-S7(for bottom mounting)
: MDF-S740T(for top mounting)
 Specification

MDF-U537D
Items Specification
Model description Biomedical freezer
Model Number MDF-U537D
Outer dimension (Max) W 804 × D 772 × H 1802 mm
Upper chamber W 658 × D 607 × H 589 mm
Inner dimension
Lower chamber W 658 × D 607 × H 603 mm
Effective chamber capacity 452 lit.
Exterior Zinc galvanized steel w/powder polyester coating (PCM)
Interior Polystyrene resin
Insulation Rigid polyurethane foam
Zinc galvanized steel w/powder polyester coating (PCM)
Outer door
2 pcs (upper and lower compartment)
Latch 2 pcs
Door lock 1 pc
(M) 6 pcs (upper compartment)
Inner dimension: W 290×D536×H136 mm
Basket
Accessories (S) 8 pcs (lower compartment)
Inner dimension: W 290×D536×H100mm
Others Defrosting spatula 1 pc, key 1 set, 14 card holders
Caster 4 pcs
Leveling legs 2 pcs (with caster)
Access hole φ 30mm. 2 places on rear.
Weights 136 Kg
Evaporator Tube on sheet type (function both evaporator and shelf)
Condenser Wire and tube type
Compressor Hermetic type 350W
HFC refrigerant
Refrigerant
R-407D
Cooling performance -30℃ (internal 1/2h air temperature, AT：35℃, no load)
Internal temperature control -20℃~-30℃
range (AT：5℃~35℃、no load)
Power supply Local voltage
MDF-U537D
Items Specification
Microprocessor controlled system with non-volatilized memory.
Temperature controller
Temp. set range : -18℃～-40℃
Temperature sensor Thermistor 2P (upper and lower compartment)
LED digital display (green colored) by 1℃.
Temperature display Range : -50℃～50℃
Selectable to display upper or lower compartment by switch.
Changeable SV±5℃～15℃. (Initial SV±10℃)
High/Low
Temperature ALARM lamp brinks and buzzer sounds intermittently
(about 15 min. delay)
Remote alarm contact: turns ON during power failure alarm.
Alarm
ALARM lamp brinks, buzzer sounds intermittently, remote alarm
Power failure
contact turns ON during power failure alarm.
Remote alarm Remote alarm terminal 3P: contact capacity DC30v, 2A, N.O. –COM.
contact (During power failure, temperature alarm: ON)
ALARM lamp
BUZZER: Buzzer key
ALARM TEST: Alarm test key
SET: To switch the SV and PV
Control panel ＞: To shift the set digit
Operation
panel ∧: To change the SV
DEF: Defrost key
TOP/BOTTOM: Switch key to display upper or lower compartment.
Power switch (Breaker switch)
Rear
Battery switch: Power failure alarm switch
Press ＞ key for five seconds
Key lock function
L0: Unlock L1: Lock
When each sensor is in fault,
Self diagnosis function Error code and internal temperature are displayed alternately.
Remote alarm contact turns ON with buzzer sounds.
Power switch Breaker switch
Overload relay
Detect temperature near compressor by thermistor sensor to control
Compressor protection compressor during overload.
Alarm: Error code and internal temperature are displayed alternately.
Remote alarm contact turns on with buzzer sounds.
Chart recorder: MTR-G85
Option Mounting kit: MPR-S7(for bottom mounting)
: MDF-S740T(for top mounting)
 Dimensions
＜MDF-U333＞
＞
 Dimensions
MDF-U537
 Dimensions
＜MDF-U537D＞
＞
 Refrigeration circuit

MDF-U333 Unit：ｍｍ

Parts description Specification

Evaporator Type Tube on sheet
Material Aluminum (φ 8.0)
Dehydrator Type of molecular sieves ４A-XH9（134 stamped）
Charged q’ty 8±1g
Capillary tube Resistance 0.686MPaG （7Kgｆ／㎠ G）
Dimension φ 1.8×(φ 0.65)×2000mm
Resistance indicator color White
Condenser assembly A Type Wire and tube
w
Dimension 480×P40×30 columns
Condenser assembly B Type Wire and tube
Dimension w
480×P40×30 columns
Note: Lower 2 columns are used
in desuper circuit.
Frame pipe Material C1220T-1/2H
Dimension φ 4.0×ｔ0.5
Evacuation and vacuum Evacuation time: over than 20min. by 2 ports (high pressure and low
pressure pressure side). (N2 exchange)
When charged, vacuum pressure is lower than 1.0torr
（pump capacity： 300L/min）
Refrigerant and oil Refrigerant : R-134a Charged q’ty : 226±5g
Oil : CF－32 Charged q’ty : 230±10cc
Oil additive: n-pentane Charged q’ty : 14g
Refrigeration circuit spec.
Refer to following pages
and welding points
 Refrigeration circuit

MDF-U537 Unit：ｍｍ

Parts description Specification

Evaporator
Type 9lines×1column×5pcs
Upper (1)
Lower (1)
Bottom (3) Material Aluminum (φ 8.0)
Dry core Type D-S032T
Manufacturer SANYO
Solid core 50cm3
Capillary tube Resistance 0.725MPaG （7.4Kgｆ／㎠ G）
(Total number: 2) Dimension φ 1.8×L4500
Resistance indicator color Blue
Condenser assembly Type Wire and tube
w
front (Total number: 4) Dimension 480×P40×6 columns
Frame pipe Material C1220T
Dimension φ 4.0×ｔ0.5×L7470
Evacuation and vacuum Evacuation time: over than 20min. by 2 ports (high pressure and low
pressure pressure side). (N2 exchange)
When charged, vacuum pressure is lower than 1.0torr
（pump capacity： 300L/min）
Refrigerant and oil Refrigerant : R-407D Charged q’ty : 301±5g
Oil : CF－32 Charged q’ty : 280±10cc
Oil additive: n-pentane Charged q’ty: 19g
Refrigeration circuit spec.
Refer to following pages
and welding points
 Refrigeration circuit

MDF-U537D Unit：ｍｍ

Parts description Specification

Evaporator assembly
Type 9lines×1column×5pcs
Upper (1)
Lower (1)
Bottom (2) Material Aluminum (φ 8.0)
Lower entrance (1)
Dry core Type D-S032T
Manufacturer SANYO
Solid core 50cm3
Capillary tube Upper compartmnt Lower compartmnt
Resistance 10.3Kg/㎠ G 9.9Kg/㎠ G
L
Dimension φ 1.8× 4000 φ 1.8×L3000
Resistance indicator color
Yellow Red
Condenser assembly Type Wire and tube
w
front (Total number: 4) Dimension 480×P40×6 columns
Frame pipe Material C1220T
Dimension φ 4.0×ｔ0.5×L7470
Evacuation and vacuum Evacuation time: over than 20min. by 2 ports (high pressure and low
pressure pressure side). (N2 exchange)
When charged, vacuum pressure is lower than 1.0torr
（pump capacity： 300L/min）
Refrigerant and oil Refrigerant : R-407D Charged q’ty : 357±5g
Oil : CF－32 Charged q’ty : 280±10cc
Oil additive: n-pentane Charged q’ty : 23g
Refrigeration circuit spec.
Refer to following pages
and welding points
 Refrigeration circuit principle diagram
＜MDF-U333＞
＞
 Refrigeration circuit welding points

＜MDF-U333＞
＞
 Refrigeration circuit principle diagram
＜MDF-U537＞
＞
 Refrigeration circuit welding points

＜MDF-U537＞
＞
 Refrigeration circuit principle diagram
＜MDF-U537D＞
＞
 Refrigeration circuit welding points

＜MDF-U537D＞
＞
 Electrical Parts

MDF-U333 AC110V,60Hz AC115V,60Hz AC220-240V , 50/60Hz

Compressor Type C-2SN220L0W C-2SN220L2W C-2SN220L5W
Code 80771120 80771122 80771125
Rated voltage (50/60Hz) 100 / 100 , 110 -- / 115 220,240 / 220
Winding resistance C-S(Aux) 5.8Ω 7.2Ω 30.6Ω
C-R(Main) 1.6Ω 2.0Ω 7.8Ω
Starting relay Type AMVL-180A AMVL-180A AMVL-300A
Pick up voltage(50Hz) AC91V 111V AC91V 111V AC185V 217V
(60Hz) AC108 128V AC108 128V AC215 232V
Drop out voltage(50Hz) AC30 65V AC30 65V AC60 120V
(60Hz) AC30 75V AC30 75V AC69 132V
Overload relay Type P24KU P19KU P10MU
Action to the temp. (No current)
OFF 150±10℃ 150±10℃ 130±8℃
ON 85±10℃ 85±10℃ 69±10℃
Action to the current (AT25 ) 24.0A 19.5A 10A
Operation time 6～15 seconds 6～15 seconds 6～15 seconds
Non-Action to the temp. (80℃）

6.1A more than 5.4A more than 2.5A more than

Non-Action 30 minutes 30 minutes 30 minutes
Action 8.0A within 15 minutes 7.4A within 15 minutes 3.4A within 15 minutes
Starting capacitor Rating 100 F,160VAC 100 F,160VAC 30 F,300VAC
Running capacitor Rating 25μF,220VAC 20μF,220VAC 5μF,400VAC
Temp. control relay Type G4F-11123T G4F-11123T G4F-11123T
Contact capacity AC220V,20A AC220V,20A AC220V,20A
Coil DC12V DC12V DC12V
Switching power supply Type ZWS10-12/J ZWS10-12/J ZWS10-12/J
AC100-240V AC100-240V AC100-240V
Input
50/60Hz,0.3A 50/60Hz,0.3A 50/60Hz,0.3A
Rated output DC12V,0.85A DC12V,0.85A DC12V,0.85A
Temperature sensor Type 502AT-1 502AT-1 502AT-1
Rating 5k ,25 5k ,25 5k ,25
P.C.B. Type DF-333 DF-333 DF-333
Battery Type 5HR-AAC 5HR-AAC 5HR-AAC
Rating 6V 1100MAH 6V 1100MAH 6V 1100MAH
Battery switch Type SLE6A2-5 SLE6A2-5 SLE6A2-5
Rating AC250V 4A AC250V 4A AC250V 4A
Breaker switch Type BAM215131 BAM215131 BAM215131
Rating AC250V 15A AC250V 15A AC250V 15A
 Electrical Parts

MDF-U537 AC110-115V,60Hz AC220V,50/60Hz AC230V-240V,50Hz

Compressor Type C-2SN350L0R C-2SN350L5S C-2SN350L5S
Code 807764201 807763251 807763251
Rated voltage (50/60Hz)
Winding resistance C-S(Aux) 5.8Ω 30.6Ω 30.6Ω
C-R(Main) 1.6Ω 7.8Ω 7.8Ω
Starting relay Type AMVL-180A AMVL-300A AMVL-300A
Pick up voltage(50Hz) AC91V 111V AC185V 217V AC185V 217V
(60Hz) AC108 128V AC215 232V AC215 232V
Drop out voltage(50Hz) AC30 65V AC60 120V AC60 120V
(60Hz) AC30 75V AC69 132V AC69 132V
Overload relay Type P18AU P10MU P10MU
Action to the temp. (No current)
OFF 120±8℃ 130±8℃ 130±8℃
ON 69±10℃ 69±10℃ 69±10℃
Action to the current (AT25 ) 18.5A 10A 10A
Operation time 6～15 seconds 6～15 seconds 6～15 seconds
Non-Action to the temp. (80℃）

4.0A more than 2.5A more than 2.5A more than

Non-Action 30 minutes 30 minutes 30 minutes
Action 5.5A within 15 minutes 3.4A within 15 minutes 3.4A within 15 minutes
Starting capacitor Rating 100 F,160VAC 30 F,300VAC 30 F,300VAC
Running capacitor Rating 25μF,220VAC 5μF,400VAC 5μF,400VAC
Temp. control relay Type G4F-11123T G4F-11123T G4F-11123T
Contact capacity AC220V,20A AC220V,20A AC220V,20A
Coil DC12V DC12V DC12V
Solenoid valve Type G2R-1A-T G2R-1A-T G2R-1A-T
control relay Contact capacity AC250V,10A AC250V,10A AC250V,10A
Coil DC12V DC12V DC12V
Switching power supply Type ZWS10-12/J ZWS10-12/J ZWS10-12/J
AC100-240V AC100-240V AC100-240V
Input
50/60Hz,0.3A 50/60Hz,0.3A 50/60Hz,0.3A
Rated output DC12V,0.85A DC12V,0.85A DC12V,0.85A
Temperature sensor Type 502AT-1 502AT-1 502AT-1
Rating 5k ,25 5k ,25 5k ,25
Solenoid valve control Type 502AT-1 502AT-1 502AT-1
sensor Rating 5k ,25 5k ,25 5k ,25
Compressor protect sensor Type 502AT-1 502AT-1 502AT-1
Rating 5k ,25 5k ,25 5k ,25
P.C.B. Type DF-537 DF-537 DF-537
Battery Type 5HR-AAC 5HR-AAC 5HR-AAC
Rating 6V 1100MAH 6V 1100MAH 6V 1100MAH
Battery switch Type SLE6A2-5 SLE6A2-5 SLE6A2-5
Rating AC250V 4A AC250V 4A AC250V 4A
Breaker switch Type BAM215131 BAM215131 BAM215131
Rating AC250V 15A AC250V 15A AC250V 15A
Solenoid valve coil Type NEVAC120V NEVAC220V NEVAC240V
Rating 120V 50/60Hz 220V 50/60Hz 240V 50/60Hz
Condensing fan motor Type FU2-A051B1MP FU2-A051B5MP FU2-A051B5MP
Rating AC110-115V 50/60Hz 220-240V 50/60Hz 220-240V 50/60Hz
Thermal fuse 130 130 130
 Electrical Parts

MDF-U537D AC110-115V,60Hz AC220V,50/60Hz AC230V-240V,50Hz

Compressor Type C-2SN350L0R C-2SN350L5S C-2SN350L5S
Code 807764201 807763251 807763251
Rated voltage (50/60Hz)
Winding resistance C-S(Aux) 5.8Ω 30.6Ω 30.6Ω
C-R(Main) 1.6Ω 7.8Ω 7.8Ω
Starting relay Type AMVL-180A AMVL-300A AMVL-300A
Pick up voltage(50Hz) AC91V 111V AC185V 217V AC185V 217V
(60Hz) AC108 128V AC215 232V AC215 232V
Drop out voltage(50Hz) AC30 65V AC60 120V AC60 120V
(60Hz) AC30 75V AC69 132V AC69 132V
Overload relay Type P18AU P10MU P10MU
Action to the temp. (No current)
OFF 120±8℃ 130±8℃ 130±8℃
ON 69±10℃ 69±10℃ 69±10℃
Action to the current (AT25 ) 18.5A 10A 10A
Operation time 6～15 seconds 6～15 seconds 6～15 seconds
Non-Action to the temp. (80℃）

4.0A more than 2.5A more than 2.5A more than

Non-Action 30 minutes 30 minutes 30 minutes
Action 5.5A within 15 minutes 3.4A within 15 minutes 3.4A within 15 minutes
Starting capacitor Rating 100 F,160VAC 30 F,300VAC 30 F,300VAC
Running capacitor Rating 25μF,220VAC 5μF,400VAC 5μF,400VAC
Compressor relay Type G4F-11123T G4F-11123T G4F-11123T
Contact capacity AC220V,20A AC220V,20A AC220V,20A
Coil DC12V DC12V DC12V
Temp. control relay Type G2R-1A-T G2R-1A-T G2R-1A-T
Contact capacity AC250V,10A AC250V,10A AC250V,10A
Coil DC12V DC12V DC12V
Switching power supply Type ZWS10-12/J ZWS10-12/J ZWS10-12/J
AC100-240V AC100-240V AC100-240V
Input
50/60Hz,0.3A 50/60Hz,0.3A 50/60Hz,0.3A
Rated output DC12V,0.85A DC12V,0.85A DC12V,0.85A
Temperature sensor Type 502AT-1 502AT-1 502AT-1
Rating 5k ,25 5k ,25 5k ,25
Solenoid valve control Type 502AT-1 502AT-1 502AT-1
sensor Rating 5k ,25 5k ,25 5k ,25
Compressor protect sensor Type 502AT-1 502AT-1 502AT-1
Rating 5k ,25 5k ,25 5k ,25
P.C.B. Type DF-537D DF-537D DF-537D
Battery Type 5HR-AAC 5HR-AAC 5HR-AAC
Rating 6V 1100MAH 6V 1100MAH 6V 1100MAH
Battery switch Type SLE6A2-5 SLE6A2-5 SLE6A2-5
Rating AC250V 4A AC250V 4A AC250V 4A
Breaker switch Type BAM215131 BAM215131 BAM215131
Rating AC250V 15A AC250V 15A AC250V 15A
Solenoid valve coil Type NEVAC120V NEVAC220V NEVAC240V
(2 pcs.) Rating 120V 50/60Hz 220V 50/60Hz 240V 50/60Hz
Condensing fan motor Type FU2-A051B1MP FU2-A051B5MP FU2-A051B5MP
Rating AC110-115V 50/60Hz 220-240V 50/60Hz 220-240V 50/60Hz
Thermal fuse 130 130 130
 Specifications of sensor

The following show temperature and resistance characteristics on each thermistor sensor
(type 502).

Temperature Resistance Temperature Resistance Temperature Resistance

（℃） （kΩ ） （℃） （kΩ ） （℃） （kΩ ）
－50 154.50 －7 17.92 12 8.17
－45 116.50 －6 17.16 13 7.85
－40 88.85 －5 16.43 14 7.55
－35 68.15 －4 15.74 15 7.27
－30 52.84 －3 15.08 16 6.99
－25 41.19 －2 14.45 17 6.73
－20 32.43 －1 13.86 18 6.48
－19 30.92 0 13.29 19 6.24
－18 29.50 1 12.74 20 6.01
－17 28.14 2 12.22 25 5.00
－16 26.87 3 11.72 30 4.18
－15 25.65 4 11.25 35 3.51
－14 24.51 5 10.80 40 2.96
－13 23.42 6 10.37 45 2.51
－12 22.39 7 9.96 50 2.14
－11 21.41 8 9.57 55 1.83
－10 20.48 9 9.20 60 1.57
－9 19.58 10 8.84
－8 18.73 11 8.49
 ＜MDF-U333・
・537・
・537D＞ ＞
１．
BZ ：When alarm lamp is blinking and buzzer sounds, buzzer and remote alarm
Output …………Force to turn off
In F25, setting value (time) is except for 000;buzzer will turn ON after the
setting time has passed. (This RING BACK function would be carried out in
s/n 110XXXXX or bigger)
：Buzzer is not turned off during alarm test.
：When alarm lamp is blinking and buzzer is off, buzzer will not turn on.
：When press this key during power failure, current internal temperature is
displayed for 5 seconds.

SET ：Press once to setting mode and press again to memorize the set value.
(It works as ENTER key)

DEF ：In PV display keep pressing the key over 5 seconds to start defrosting.
During defrosting, press the key to quit defrosting.
During defrosting, internal temperature and “dF” is displayed alternately.
During defrosting, high-low temperature alarm is cancelled.
When sensor error is occurred during defrosting, error code and internal
temperature is displayed alternately, and “dF” display is turned off.
During defrosting, only buzzer key is acceptable.

ALARM TEST：Press the key in PV display, alarm test will be start.

Press again then quit alarm test.
During alarm test, alarm lamp will blink and buzzer will sound intermittently.
Digital display will be turned off.
During alarm test, only alarm test key is acceptable.

：During setting mode, shift between the first digit and the second digit.
In PV display, keep pressing the key over 5 seconds to enter the key lock
mode. (“L0”display)

：During setting mode, count up the blinking digit. In PV display, keep

pressing the key over 5 seconds to enter the function mode (“F00” display)

TOP/BOTTOM ：This key is available only in MDF-U537D.

Initially TOP (upper compartment) temperature is displayed.
Press key to display BOTTOM (lower compartment) temperature.
Press this key during power failure to display compartment temperature for 5
seconds, that was not selected before power failure.
２．Temperature
２． control and High, Low temperature alarm
<Temperature control>
Setting range ： -18℃～-40℃
Display range ： -50℃～+50℃
Setting method ：Press SET key and set the required value with key and
Key. Press SET key again to memorize the set value,
And then return to PV display.
Out of setting range : If change to out of setting range value by mistake and press
SET key , buzzer sound continuously for 1 second.

<Alarm>
High temperature alarm ：
When the internal temperature is higher than SV (+5℃～+15℃), alarm lamp and
digital display is blinking. After 15min.later, buzzer will sound and remote alarm
contact will turn ON. (initial value: +10℃)

Low temperature alarm ：

When the internal temperature is lower than SV（-5℃～-15℃）, alarm lamp and digital
display is blinking. After 15min.later, buzzer will sound and remote alarm contact will
turn ON. (initial value: -10℃)

Setting method ：
Keep pressing key over 5 seconds to enter function mode (“F00”).
Then press key to count up value. Change “F01” to input high temperature alarm
value, “F02” to input low temperature alarm value.
Set either “F01” or “F02” then press SET key to turn alarm temperature setting mode
to set required value with key and key.
Press SET key again to memorize value.

Out of setting range ：

If change to out of setting range value by mistake and press SET key, sound buzzer
continuously for 1second and remain in setting mode to maintain the setting value.

３． Defrosting
This function is different by each model code (products) .
a. In PV display keep pressing DEF key over 5 seconds, defrosting will be started.
Model code 001 (MDF-U333) --- Force to turn compressor OFF.
Model code 002 (MDF-U537) --- Force to turn compressor & solenoid valve OFF. (Use 1 solenoid valve)
Model code 003 (MDF-U537D)
--- Single compartment → Force to turn OFF solenoid valve at the ROOM lamp illuminated.
--- Both compartments → Force to turn OFF 2 solenoid valves & compressor.
b. Press again DEF key to quit defrosting.（Manual start and finish）
４． Self diagnosis function
E01 ： Temperature sensor (upper compartment temperature sensor for MDF-U537D)
is open circuit
E02 ： Temperature sensor (upper compartment temperature sensor for MDF-U537D)
is short circuit
E03 ： Lower compartment temperature sensor is open circuit （for MDF-U537D only）
E04 ： Lower compartment temperature sensor is short circuit （for MDF-U537D only）
E05 ： Compressor protect sensor is open circuit (for MDF-U537,U537D)
E06 ： Compressor protect sensor is short circuit (for MDF-U537,U537D)
E07 ： Solenoid valve control sensor is open circuit (for MDF-U537 only)
E08 ： Solenoid valve control sensor is short circuit (for MDF-U537 only)
E09 ： Buttery switch OFF with ALARM TEST
E10 ： Compressor temperature is abnormal （for MDF-U537, U537D）

a. Model code setting (for code: 001,002,003)

When temperature sensor is open circuit, display shows alternately E01 with –50℃.
When temperature sensor is short circuit, display shows alternately E02 with +50℃.
b. Model code setting (for code: 002)
When solenoid valve control sensor is open circuit, display shows alternately E07 with
–50℃.
When solenoid valve control sensor is short circuit, display shows alternately E08 with
+50℃.
c. Model code setting (for code: 003)
When TOP lamp is displayed, display shows same as a. in upper compartment.
When BOTTOM lamp is displayed, display shows lower compartment temperature.
When lower compartment temperature sensor is open circuit, display shows alternately
E03 with –50℃.
When lower compartment temperature sensor is short circuit, display shows alternately
E04 with +50℃.
d. Error diagnosis
Self diagnosis of open circuit is done when it is lower than -60℃.
Self diagnosis of short circuit is done when it is higher than +60℃.
E09 is functioned only during ALARM TEST is performed.
In E10 is displayed: When condenser temperature is higher than 85℃, it diagnoses as
abnormal and indicate E10. When condenser temperature is higher
than 100℃ force to turn compressor OFF.
When condenser temperature is lower than 65℃, it diagnoses as
normal and cancel to force compressor turn OFF.
When numbers of error happened simultaneously, error code of smallest number will be
displayed. With exception for MDF-U537D, alternative display of error code and PV,which
is selected compartment internal temperature .
During power failure, display shows alternately E09 with blank.
５． Key lock function
In PV display、Keep pushing key over 5 seconds to enter key lock mode displaying with
“L0”.
Push key to 1 ・・・・・key lock ON
0 ・・・・・key lock OFF
then press SET key to memorize set value then return to PV display.
Note） With key lock ON to enter SET mode, but unable to change value.
With key lock ON to perform Function and ALARM TEST, while unable to perform
DEF.

６． Power failure alarm (Buzzer and display isn’t functioned without buttery power
supplied)
When power failure is occurred, power failure alarm will be turned on by battery inside units.
During power failure alarm, alarm lamp is blinking, digit display turns off, buzzer sounds
intermittently and remote alarm contact turns ON.
Press BZ key to turn power failure alarm buzzer OFF.
Press BZ key to display PV for 5 seconds.
During power failure alarm, only BZ key (TOP/BOTTOM key for MDF-U537D) is available.

７． Alarm test
The function is to check performance (failure) for alarm lamp, buzzer and remote alarm.
In PV display, press ALARM TEST key to blink alarm lamp, to sound buzzer intermittently, to
turn remote alarm contact on (Without time delay). Digital display will be turned off.
During alarm test, only ALARM TEST key is available.
Note: During alarm test, with buttery switch turned OFF to display error code E09.
Displaying error code E09 takes priority over other error codes before ALARM TEST is
performed.

８． Auto return function

Function: During setting mode or key lock mode or function mode with any key not pressed
for 90 seconds, value will not be memorized to return to PV mode automatically.
Note: In F09 or F10, auto return function will not be performed.

９． Compressor delay start time

During cycle time, normally force to turn compressor OFF after 2 minutes passed compressor
turned off.
When main power is supplied (microcomputer is RESET), changeable to set compressor time
lag for 1 ～15 minutes. (See F05)
１０．Function
１０． mode
Functions are as follow.
F00 ： To return to PV display
F01 ： To change temperature of high temperature alarm
F02 ： To change temperature of low temperature alarm
F03 ： To change temperature of high temperature alarm
(Applied for lower compartment of MDF-U537D)
F04 ： To change temperature of low temperature alarm
(Applied for lower compartment of MDF-U537D)
F05 ： To set compressor delay start time
F06 ： To input service code (384)
F07 ： To adjust zero for temperature sensor
(Upper compartment sensor for MDF-U537D)
F08 ： To adjust zero for temperature sensor
(Not available for MDF-U333)
(Solenoid valve control sensor for MDF-U537)
(Lower compartment sensor for MDF-U537D)
F09 ： Not available
F10 ： Not available
F11 ： Not functioned. Return to PV display.
F12 ： To display temperature of temperature sensor (per 0.1℃)
F13 ： To display temperature of MDF-U537/U537D compressor protect sensor (per 1℃)
F14 ： To display temperature of temperature sensor (per 0.1℃)
(Solenoid valve control sensor for MDF-U537)
(Lower compartment sensor for MDF-U537D)
F15 ： Not available
F16 ： Not functioned. Return to PV display.
F17 ： To set or check model code
model code 001： MDF-U333
model code 002： MDF-U537
model code 003： MDF-U537D
F18 ： Preset value for second offset performance: -26℃ (for MDF-U537/U537D)
F19 ： Not functioned. Return to PV display.
F20 ： Not functioned. Return to PV display.
F21 ： To set communication ID（000～255）
F22 ： To set communication mode
F23,24,26～29 ： With input each function code, press SET key to sound buzzer 1 second
continuously to maintain input status.
F25 ： To set alarm ring back time
Setting value: 000,010,020,030,040,050,060

Setting method ：
In PV display, keep key pressing over 5 seconds to enter function mode and will be
displayed “F00”. Press key to input required function code then press
SET key again.

F00 ： Not functioned. In F00 displayed, press SET key to return PV display.
F01 ： To set temperature of high temp. alarm performance in the range of +5℃～+15℃.
(initial value : +10℃)

F02 ： To set temperature of low temp. alarm performance in the range of -5℃～-15℃.
(initial value : -10℃)

F03 ： To set temperature of high temp. alarm performance in the range of +5℃～+15℃.
(initial value : +10℃)
Return to PV display except for lower compartment of MDF-U537D.

F04 ： To set temperature of low temp. alarm performance in the range of -5℃～-15℃.
(initial value : -10℃)
Return to PV display except for lower compartment of MDF-U537D.

F05 ： To set compressor delay start time

（performed only when main power supplied or microcomputer reset）
The function is to reduce compressor’s start up failure or breaker’s blown out that
caused by numbers of units simultaneous start up after power failure.
The setting range of time lag is 1～15 minutes. (Initial value is 1 minute on factory
outgoing)
SV before doing factory’s performance test, is 3 seconds or less. Therefore, the time
lag is 0 (3 seconds) when PCB replacement is done in service. It is recommended to
input 1～15 for value when PCB is replaced.

F06 ： Input service code with key and key when F07 and following functions,
except F21, F22 and F25 would be performed. Press SET key to memorize service
code to enter function mode again to perform F07 and following functions.
Service code : 384
Note）Service code is memorized unless input “000” again in ”F06”, or turn power OFF.
(Turn OFF = buttery switch and power supply switch are turned OFF)
Note) After using service code on service, input “000” again in “F06”.

F07 ：To adjust 0 of temperature sensor (setting range: -9.9℃～+9.9℃)

Setting method: In ”Ｆ07” displayed, press SET key to display ”00.0”（initial value）.
Set temperature with key and key and press SET key
again to memorize set value. Input is done by differential value.

Ex） When actual temperature of 1/2h is shown –28.5℃and digital display is

shown -30℃, add +1.5 to value in F07.
Calculation = (-28.5-(-30)) = +1.5

key enables to change only “0” and “-“ in second digit and to change
“0”～”9” in first digit and first decimal place.
key enables to shift the second digit ⇔ the first digit ⇔
the first decimal place⇔the second digit.
F08 ：To adjust 0 of temperature sensor （setting range: -9.9℃～+9.9℃）
In F17: It is functioned in model code 002(MDF-U537), 003(MDF-U537D).
Return to PV display in model code 001(MDF-U333)
Setting method: In ”Ｆ08” displayed, press SET key to display ”00.0”（initial value）.
Set temperature with key and key and press SET key
again to memorize set value. Input is done by differential value.

Ex） When actual temperature of 1/2h chamber is shown –28.5℃and digital

display is shown -30℃, add +1.5 to value in F08.
Calculation = (-28.5-(-30)) = +1.5
key enables to change only “0” and “-“ in second digit and to change
“0”～”9” in first digit and first decimal place.
key enables to shift the second digit ⇔ the first digit ⇔
the first decimal place⇔the second digit.

Ｆ12 ：Temperature of temperature sensor is displayed as per 0.1℃.

From second digit to first decimal point is shown in display.
It is not shown “-“ in display when temperature is lower than -20℃.
(Ex. Actual temperature -35℃ → Display shows 35.0℃)
When temperature is within the range of -19.9℃～-0.1℃, ”-“ is displayed.
Range : -72.0～+83.0℃（±9.9℃）

Ｆ13 ：Temperature of compressor protect sensor is displayed as per 1℃.

Range: -72～+163℃

Ｆ14 ：Temperature sensor (solenoid valve control sensor for MDF-U537, lower compartment
temperature control sensor for MDF-U537D)
Temperature of each sensor is displayed as per 0.1℃
From second digit to first decimal point is shown in display.
It is not shown “-“ in display when temperature is lower than -20℃.
(Ex. Actual temperature -35℃ → Display shows 35.0℃)
When temperature is within the range of -19.9℃～-0.1℃, ”-“ is displayed.
Range : -72.0～+83.0℃
 F17 ：Model code setting or checking
001 ：MDF-U333
002 ：MDF-U537
002 ：MDF-U537D

Followings are initial setting values

Internal temp. SV ： -30℃ (for U537D : both compartments)
Key lock mode ： 0 （OFF）
High temperature alarm ： SV+10℃(for U537D : both compartments)
Low temperature alarm ： SV-10℃(for U537D : both compartments)
0 adjustment：+0℃（for temperature sensor）
Compressor start delay time ： 1 minute
Communication ID ： 000
Communication mode ： 000
Alarm ring back time ： 030 (30 minutes)
Set model code as MDF-U537, MDF-U537D to activate compressor protect function.

F21 ： To set serial communication ID.

Input range: 000～255 （000 means that communication is OFF）

F22 ： To set serial communication mode.

Control mode （3rd digit） 0 ： Local （initial value）
1 ： Remote
nd
Baud rate （2 digit） 0 ： 2400bps （initial value）
1 ： 4800bps
2 ： 9600bps
st
1 digit is not used.
Note） Set control mode as “remote” unable to change SV and to activate defrosting.

F25 ： To set value for alarm recovery (ring back) time.

Input value: 000,010,020,030,040,050,060 (In 000, recovery function is OFF)

１１．Differential
１１． （COMP. ON/OFF point on program）
COMP ON permit ： Activate at +0.0℃ higher than SV
COMP OFF： Activate at -0.6℃ lower than SV
１２．Offset
１２． value
The function is to correct differential value between temperature of temperature sensor and
of internal 1/2H (centre of chamber).
Initial offset
001 (MDF-U333): Shift –1.5℃from temperature of temperature control sensor (PV)
002 (MDF-U537): Shift +1.0℃from temperature of temperature control sensor (PV)
(For upper, lower compartment)
003 (MDF-U537D): Shift +0.0℃from temperature of temperature control sensor (PV)
(For upper, lower compartment)
Second offset
001 (MDF-U333): None
002 (MDF-U537):-18℃≧SV≧-25℃--- shift –0℃from PV (For upper, lower compartment)
-26℃≧SV -- shift +1.0 from PV (For upper, lower compartment)
003 (MDF-U537D):-18℃≧SV≧-30℃--- shift PV-2.4+(-18-SV)÷5 (For upper compartment)
-30℃＞SV --- shift –0℃from PV (For upper compartment)
*Note) For lower compartment, add 0℃ to PV.

１３．Display
１３． offset
In display, temperature that is lower than SV is shown for a little time. With this case, display
offset –0.5℃should be done. (Round off numbers to the first decimal point)

１４．Remote
１４． alarm
During normal operation … … … Remote alarm contact is OPEN
During alarm or power failure … … … Remote alarm contact is CLOSE

１５．Others
１５．
MDF-U537: In case of : -18℃≧SV≧–25℃ with PV-SV+5℃≧0
Solenoid valve is: Forced to turn OFF

MDF-U537: In case of : PV-(SV-0.6℃)≧0 with PVTOP - PVBOTTOM -1＞0

Solenoid valve is: Forced to turn OFF
(In PV-(SV-0.6)＜0, quit to be forced to turn OFF)
Wiring diagram
Circuit diagram
<Main PCB>
 Components on PCB
<Main PCB>
 Test data

･ＭＤＦ－Ｕ３３３ Pull down 40

･ＭＤＦ－Ｕ３３３ Pull up 40
･ＭＤＦ－Ｕ３３３ Cooling unit pressure 41
･ＭＤＦ－Ｕ３３３ Power consumption 41
･ＭＤＦ－Ｕ３３３ Temperature uniformity and fluctuation 42
･ＭＤＦ－Ｕ５３７ Pull down 43
･ＭＤＦ－Ｕ５３７ Pull up 43
･ＭＤＦ－Ｕ５３７ Cooling unit pressure 44
･ＭＤＦ－Ｕ５３７ Power consumption 44
･ＭＤＦ－Ｕ５３７D Pull down 45
･ＭＤＦ－Ｕ５３７D Pull down 45
･ＭＤＦ－Ｕ５３７D Pull up 46
･ＭＤＦ－Ｕ５３７D Cooling unit pressure 47
･ＭＤＦ－Ｕ５３７D Power consumption 47
･ＭＤＦ－Ｕ５３７/D Temperature uniformity and fluctuation 48
 ＭＤＦ－Ｕ３３３ Pull down

40

30 50Hz 60Hz

20
Internal temperature [℃]

10

-10

-20

-30

-40
0 2 4 6 8 10
Time scale [H]

ＭＤＦ－Ｕ３３３ Pull up

20

10
Internal temperature [℃]

-10

-20

-30

-40
0 2 4 6 8
Time scale[H]
 ＭＤＦ－Ｕ３３３ Cooling unit pressure

Pd(50Hz) Ps(50Hz) Pd(60Hz) Ps(60Hz)

1600
AT35℃，no load
1400

1200
Pressure ［kPa］

1000

800

600

400

200

0
0 1 2 3 4 5 6 7
Time scale ［ｈ］

ＭＤＦ－Ｕ３３３ Power consumption

W(50Hz) W(60Hz)
250
AT35℃，no load

200
Power consumption［Ｗ］

150

100

50

0
0 1 2 3 4 5 6 7
Time scale ［ｈ］
ＭＤＦ－Ｕ３３３
Temperature uniformity and fluctuation

（Test condition）
Mains : 1φ100V50/60Hz
AT : 35℃
SV ： -25℃・-20℃・-30℃
No load Measure with type T sensor

Measuring point：Center point of each container

４
５

（１）．ＳＶ＝－２５℃
Measuring point Temperature(℃） Fluctuation(℃）
Top 1 -21.8
2 -23.2
Middle 3( 1/2 center air) -24.3 ± 2.0
4 -24.6
Bottom 5 -24.2
Uniformity Max./Min -21.8/-24.6
Range(deg) 2.8(±1.4)

（２）．ＳＶ＝－２０℃
Measuring point Temperature(℃） Fluctuation(℃）
Top 1 -17.1
2 -18.3
Middle 3( 1/2 center air) -19.1 ± 2.6
4 -19.4
Bottom 5 -19.0
Uniformity Max./Min -17.1/-19.4
Range(deg) 2.3(±1.15)

（３）．ＳＶ＝－３０℃
Measuring point Temperature(℃） Fluctuation(℃）
Top 1 -26.3
2 -28.1
Middle 3( 1/2 center air) -29.3 ± 1.7
4 -29.4
Bottom 5 -29.1
Uniformity Max./Min -26.3/-29.4
Range(deg) 3.2(±1.6)

note）These data are reference only.

 ＭＤＦ－Ｕ５３７ Pull down
50Hz 60Hz AT 35℃，no load
40

30

20
Internal temperature［℃］

10

-10

-20

-30

-40
0 2 4 6 8 10 12
Time scale ［H］

ＭＤＦ－Ｕ５３７ Pull up
AT 35℃，no load
20

10
Internal temperature ［℃］

-10

-20

-30

-40
0 2 4 6 8 10
Time scale ［H］
 ＭＤＦ－Ｕ５３７Cooling unit pressure
Pd(60Hz) Ps(50Hz) Pd(60Hz) Ps(60Hz)
2000
AT 35℃，no load

1500
Pressure [kPa]

1000

500

0
0 2 4 6 8 10 12
Time scale [H]

ＭＤＦ－Ｕ５３７ Power consumption

W(50Hz) W(60Hz)
300
AT 35℃，no load
Power consumption[W]

200

100

0
0 2 4 6 8 10 12
Time scale [H]
 ＭＤＦ－Ｕ５３７Ｄ Pull down

40
AT35℃，50Hz，no load
30
Top chamber
20
Internal temperature［℃］

Bottom chamber

10

-10

-20

-30

-40
0 2 4 6 8 10 12
Time scale［H］

ＭＤＦ－Ｕ５３７Ｄ Pull down

40
AT35℃，60Hz，no load
30
Top chamber
20
Internal temperature［℃］

Bottom chamber

10

-10

-20

-30

-40
0 2 4 6 8 10 12
Time scale［H］
 ＭＤＦ－Ｕ５３７Ｄ Pull up

30
AT35℃，no load

20

10
Internal temperature［℃］

-10
Top chamber
Bottom
-20
chamber

-30

-40
0 2 4 6 8 10
Time scale［H］
 ＭＤＦ－Ｕ５３７Ｄ Cooling unit pressure
Pd(50Hz) Ps(50Hz) Pd(60Hz) Ps(60Hz)
2500
AT35℃，no load

2000
Pressure[kPa]

1500

1000

500

0
0 2 4 6 8 10 12
Time scale [H]

ＭＤＦ－Ｕ５３７Ｄ Power consumption

W(50Hz) W(60Hz)

500 AT35℃，no load

400
Power consumption[W]

300

200

100

0
0 2 4 6 8 10 12
Time scale[H]
ＭＤＦ－Ｕ５３７ / Ｄ temperature uniformity and fuluctuation

Mains ： 100V50Hz
AT ： 35℃
SV ：-20℃・-25℃・-30℃
No load Mesure with type T sensor
Measureing point : Center point of each container /chamber
MDF-U537 MDF-U537D

１ １ ４

２ ２

８
３ ３

４ ５ ９

５ ６

６ ７

７ ８

《 MDF-U537 》
Measuring point SV -20℃ SV -25℃ SV -30℃
1 -19.7 -24.6 -30.8
2 -20.9 -25.7 -31.7
3 -21.1 -25.4 -31.7
4 -19.6 -24.7 -29.4
5 -19.9 -24.4 -29.6
6 -21.2 -25.1 -30.7
7 -18.7 -22.8 -27.8
8 -19.9 -24.1 -29.7
Uniformity ［deg.］ 2.5 2.6 3.9
Fluctuaation［℃］ ±2.0 ±1.4 ±1.5

《 MDF-U537D 》
Measuring point SV -20℃ SV -25℃ SV -30℃
1 -17.7 -22.4 -27.4
2 -19.9 -25.1 -30.1
3 -18.8 -24.9 -30.8
4 -19.8 -24.9 -30.2
Uniformity ［deg.］ 2.2 2.7 3.4
Fluctuaation［℃］ ±3.1 ±2.1 ±0.9
5 -22.4 -25.8 -29.8
6 -21.3 -25.3 -29.5
7 -20.5 -25.8 -30.4
8 -17.9 -23.3 -28.1
9 -21.7 -26.2 -30.4
Uniformity ［deg.］ 4.5 2.5 2.3
Fluctuaation［℃］ ±3.2 ±2.6 ±1.3

note)These data are reference only

＜Memorandum＞
Parts layout
ＭＤＦ－Ｕ５３７ Electrical parts on top
Top view of product Access port for recorder wires

Inside of control panel

Connecter for buzzer

Connecter for display P.C.B.

Back view of product

Door latch

Remote alarm terminal Breaker switch

Inner parts
of door latch

・Temperature control sensor (MDF-Ｕ５３７)

・Temperature control sensor
for upper chamber (MDF-Ｕ５３７D)

・Solenoid valve control sensor (MDF-Ｕ５３７)

・Temperature control sensor
for lower chamber (MDF-Ｕ５３７D)

Connecter for tenperature recorder power sourece