Hoshizaki DD 24-S User manual

Service Manual
R290 Direct Draw Equipment
Models
DD 24 (-S)
DD 59 (-S)
DD 69 (-S)
DD 80 (-S)
DD 95 (-S)
hoshizakiamerica.com
Issued: 06-11-2018
Revised:

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Hoshizaki provides this manual primarily to assist qualified service technicians in the
service and maintenance of the appliance.
Should the reader have any questions or concerns which have not been satisfactorily
addressed, please call, send an e-mail message, or write to the Hoshizaki Technical
Support Department for assistance.
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]
HOSHIZAKI AMERICA, INC.
618 Highway 74 South
Peachtree City, GA 30269
Attn: Hoshizaki Technical Support Department
Web Site: www.hoshizaki.com
NOTE: To expedite assistance, all correspondence/communication MUST include
the following information:
•Model Number _____________________________
•Serial Number _____________________________
•Complete and detailed explanation of the problem.
WARNING
Only qualified service technicians should install and service the appliance. To
obtain the name and phone number of your local Hoshizaki Certified Service
Representative, visit www.hoshizaki.com. No installation or service should be
undertaken until the technician has thoroughly read this Instruction Manual.
Likewise, the owner/manager should not proceed to operate the appliance until
the installer has instructed them on its proper operation. Failures to install,
operate, and maintain the appliance in accordance with this manual may
adversely affect safety, performance, component life, and warranty coverage.
Proper installation is the responsibility of the installer. Product failure or property
damage due to improper installation is not covered under warranty.

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This manual should be read carefully before the appliance is serviced. Read the
warnings and guidelines contained in this manual carefully as they provide
essential information for the continued safe use, service, and maintenance of the
appliance. Retain this manual for any further reference that may be necessary.
IMPORTANT
CONTENTS
Important Safety Information............................................................................................ 4
I. General Information.......................................................................................................7
A. Construction...................................................................................................... 7
B. Refrigeration Flow Chart....................................................................................8
II. Sequence of Operation and Service Diagnosis............................................................9
A. Sequence of Operation Flow Charts................................................................. 9
B. Service Diagnosis..............................................................................................10
C. Controller Check................................................................................................13
D. Thermistor Check .............................................................................................14
E. Diagnostic Tables .............................................................................................15
III. Controller and Adjustments ........................................................................................ 17
A. Controller with Integrated Display......................................................................17
1. Controller with Integrated Display........................................................... 17
a) Display Icons ...............................................................................17
b) Controller location and Layout..................................................... 18
c) Controller Connections................................................................ 19
B. Temperature..................................................................................................... 20
1. Default Settings...................................................................................... 20
2. Temperature Setpoint............................................................................. 20
3. Changing the Temperature Display Scale (°F or °C)............................. 21
C. Defrost.............................................................................................................. 21
D. Alarm Safeties.................................................................................................. 22
E. Safety Devices.................................................................................................. 22
IV. Replacement of Components .....................................................................................23
A. Service for Refrigerant Lines ............................................................................23
B. Important Notes for Component Replacement .................................................26
V. Maintenance ................................................................................................................26
1. Condenser...............................................................................................26
2. Power Supply Connection.......................................................................26
VI. Preparing the Appliance for Periods of Non-Use........................................................ 27
VII. Disposal......................................................................................................................27
VIII. Technical Information................................................................................................28
A. Electrical and Refrigerant Data .........................................................................28
B. Wiring Diagrams................................................................................................29

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WARNING
The appliance should be destined only to the use for which it has been expressly
conceived. Any other use should be considered improper and therefore dangerous.
The manufacturer cannot be held responsible for injury or damage resulting from
improper, incorrect, and unreasonable use. Failure to service and maintain the
appliance in accordance with this manual will adversely affect safety, performance,
component life, and warranty coverage.
To reduce the risk of death, electric shock, serious injury, or fire, follow basic
precautions including the following:
• Only qualified service technicians should install and service the appliance.
• The appliance must be installed in accordance with applicable national, state, and
local codes and regulations.
• To reduce the risk of electric shock, do not touch the plug or power switch with
damp hands.
• Make sure the power switch is in the “OFF” position before plugging in or
unplugging the appliance the risk of electric shock.
•
Before servicing, move the power switch to the “OFF” position. Unplug the
appliance from electrical outlet.
•
For servicing, R290 Models is recommendable be in ventilated area with no
source of ignition.
• This appliance requires an independent power supply of proper capacity. See
name plate for electrical specifications. Failure to use an independent power
supply of proper capacity can result in a tripped breaker, blown fuse, damage to
existing wiring, or component failure. This could lead to heat generation or fire.
• THE APPLIANCE MUST BE GROUNDED: The appliance is equipped with a
NEMA 5-15 three-prong grounding plug to reduce the risk of potential shock
hazards. It must be plugged into a properly grounded, independent 3-prong wall
outlet. If the outlet is a 2-prong outlet, it is your personal responsibility to have a
qualified electrician replaces it with a properly grounded, independent 3-prong
Important Safety Information
Throughout this manual, notices appear to bring your attention to situations which could
result in death, serious injury, damage to the appliance, or damage to property.
WARNING Indicates a hazardous situation which could result in death or serious
injury.
NOTICE Indicates a situation which could result in damage to the
appliance or property.
IMPORTANT Indicates important information about the use and care of the
appliance.

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WARNING, continued
• Do not use an extension cord.
• If the power cord is damaged, replace with factory-specified cord.
• Do not use an appliance with a damaged power cord. The power cord should not
be altered, jerked, bundled, weighed down, pinched, or tangled. Such actions
could result in electric shock or fire. To unplug the appliance, be sure to pull the
plug, not the cord, and do not jerk the cord.
• Do not splash, pour, or spray water directly onto or into the appliance. This might
cause short circuit, electric shock, corrosion, or failure.
• Do not make any alterations to the appliance. Alterations could result in electric
shock, injury, fire, or damage to the appliance.
• The appliance is not intended for use by persons (including children) with reduced
physical, sensory, or mental capabilities, or lack of experience and knowledge,
unless they have been given supervision or instruction concerning use of the
appliance by a person responsible for their safety.
• Children should be properly supervised around the appliance.
• Do not climb, stand, or hang on the appliance or door or allow children or animals
to do so. Do not climb into the appliance or allow children or animals to do so.
Death or serious injury could occur or the appliance could be damaged.
• Be careful not to pinch fingers when opening and closing the door. Be careful
when opening and closing the door when children are in the area.
• Open and close the doors with care. Doors opened too quickly or forcefully may
cause injury or damage to the appliance or surrounding equipment.
• Do not use combustible spray or place volatile or flammable substances near the
appliance. They might catch fire.
• Keep the area around the appliance clean. Dirt, dust, or insects in the appliance
could cause harm to individuals or damage to the appliance.
• Do not throw anything onto the shelves or load any single shelf with more than
100 lb. (45 kg) of product. They might fall off and cause injury.
• Do not place anything on top of the appliance. Foreign objects or moisture could
enter the appliance and result in electric shock or fire.
• The appliance is designed only for temporary storage of food. Employ sanitary
methods. Use for any other purposes (
for example, storage of chemicals or
medical supplies such as vaccine and serum) could cause deterioration of stored
items.

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NOTICE
• Protect the floor when moving the appliance to prevent damage to the floor.
• Keep ventilation openings, in the appliance enclosure or in the built-in structure,
clear of obstruction. Blockage of airflow could negatively affect performance and
damage the appliance.
• To prevent deformation or cracks, do not spray insecticide onto the plastic parts or
let them come into contact with oil.
• To avoid damage to the gasket, use only the door handle when opening and
closing.
• To avoid damage to the top seal, do not lift the appliance by the top panel or
remove the top panel.
• Do not leave the doors open
WARNING, continued
• Do not block air inlets or outlets, otherwise cooling performance may be reduced.
• Do not tightly pack the cabinet. Allow some space between items to ensure good
air flow. Also allow space between items and interior surfaces.
• Do not store unpackaged product in the appliance; the appliance is for pre-
packaged food and beverages only.
• Certain products, if not stored in sealed containers, may accelerate corrosion of
the evaporator, resulting in failure; keep all containers closed.
• Do not store items near the air outlet. They might freeze up and crack or break
causing a risk of injury or contamination of other food.

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I. General Information
A. Construction

8
B. Refrigeration Flow Chart

9
II. Sequence of Operation and Service Diagnosis
A. Sequence of Operation Flow Charts
1. Refrigerator

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WARNING
•The appliance should be diagnosed and repaired only by qualified service
personnel to reduce the risk of death, electric shock, serious injury, or fire.
•
Risk of electric shock. Use extreme caution and exercise safe electrical
practices.
•Moving parts (e.g., fan blade) can crush and cut. Keep hands clear.
•Make sure all food zones are clean after the appliance is serviced.
NOTICE
•The appliance is not intended for outdoor use. Normal operating ambient
temperature must be within 45°F to 100°F (7°C to 37.4°C).
•The appliance must not be located next to ovens, grills, or other high heat
producing equipment.
•The appliance must not be located in a corrosive environment.
•The appliance must be a minimum of 2" (5 cm) from side
walls.
IMPORTANT
The maximum allowable voltage variation is ±10 percent of the nameplate rating.
115VAC is used as a reference voltage when checking voltage to components.
Voltage may vary depending on power supply.
B. Service Diagnosis
The diagnostic procedure is a sequence check that allows you to diagnose the electrical
system and components. Before proceeding, check for correct installation and proper
voltage per nameplate. Always choose a neutral to establish a good neutral
connection when checking high voltages. If the display is in alarm, see "III.D.Alarm
safeties".

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1. Factory Default Setting:
a) Temperature Settings: 32°F.
b) Temperature Display Scale: °F.
For further details, see "II.C.Controller Check" or "III.Controller and Adjustments."
Note:
• When exposed to high temperatures, a high-temperature alarm "Hi" may
occur at startup. To silence the alarm, press and release the “SET” button.
Alarm automatically resets when temperature drops to an acceptable range.
• There is a minimum 3-min. Comp on time and 3-min. Comp off time.
1) Move the power switch to the "OFF" position.
2) Unplug the appliance from the electrical outlet.
3) Remove the control box cover.
4) Plug the appliance back into the electrical outlet.
5) Move the power switch to the "ON" position.
6) Confirm 115VAC at the power switch in the top terminal (Brown) and neutral (White),
also confirm proper supply voltage at the receptacle box.
7) Startup/Cool Down - EvapFM energize. There is a slight delay of 3-min. then Comp
and ConFM energize. Cabinet temperature appears in the Display.
a) EvapFM Diagnosis: Confirm EvapFM energizes. If not, check for 115VAC at
EvapFM terminal connection in Brown and White wire. If 115VAC is not present,
check continuity between the Brown wire at power switch at the “ON” position and
Brown wire at EvapFM terminal. If there is no continuity, replace the main wiring.
If continuity does exist between the Brown wire in the power switch and the Brown
wire at the EvapFM terminal, check that Evap FM is energized and fan blades turn
freely, if not, check fan blades for binding and FM winding continuity. Replace as
needed.
b) Controller Diagnosis: Cabinet temperature appears on Display. If not, check for
115VAC at the controller terminals #6 (Brown) and #7 (White). If 115VAC is not
present, check power switch, power cord connections, and breaker/fuse. Confirm
wiring connections are secure. If 115VAC is present and the Display is off, replace
the controller.

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c) Comp and CondFM Diagnosis: Confirm Comp and CondFM energize after the
3-min. of delay at the power on. If not, check if the compressor icon appears in the
remote display, if not check the set point and the temperature in the remote
display, if the temperature is not in proper range check the CTh status. See "II.D.
Thermistor check”, If CTh ohm reading is in proper range replace controller.
If the compressor icon appears in the remote display and the set point and the
temperature in the display is correct, check If 115VAC is present at the controller
terminals #5 (Black Smooth) and #7 (White) If 115VAC is not present, check if
115VAC is present at controller terminals #4 (Black Striped) and #7 (White), if it is
present replace the controller.
If the CondFM is energized but Comp is not, check for 115VAC at Comp thermal
protector and neutral (White) in the compressor. If 115VAC is not present, give
time for Comp thermal protector to cool and reset. If Comp protector does not
reset, replace Comp protector. If 115VAC is present, check Comp start capacitor,
start relay, and Comp motor windings. If CondFM is not energized, check ConFM
fan blades for binding and motor winding continuity.
If Comp and ConFM are energized and the cabinet does not cool down, check for
a restriction in the refrigeration circuit, check the suction pressure, and correct
refrigerant charge, see "VIII. Technical information".
8) Cool Down Achieved-CTh cools to Setpoint of 32°F (0°C). EvapFM continue on, Comp
and CondFM de-energize. Diagnosis: Confirm Comp and CondFM de-energize. If not, and
Comp and CondFM were energized longer than 3-min. check if the Comp icon in the
display is off, if the Comp icon is present, check the set point. Check the CTh status. See
"II.D. Thermistor Check" If CTh ohm reading is in range and Comp and CondFM continue
longer than 3-min., check for 115VAC at the controller terminals #5 (Black Smooth) and #7
(White) If 115VAC is present replace the controller.
9) Defrost. There is a 25-min. defrost time each 6-hr. after power on or energy restore.
1b) Manual Initiation: To initiate a manual defrost, press and hold the snowflake
button for 5 seconds. The snowflake icon appears in the display. EvapFM and
LampSW continue energize Comp and CondFM de-energize. The last
temperature on display is holding during the defrost time (the temperature do not
change on the display during defrost time).
2b) Manual Termination Defrost: P ress and hold the snowflake button for
5 seconds, the snowflake icon in the display must turn off, and the compressor
icon must be blinking in the display, 3-min. Comp delay timer starts, after the
delay timers terminate the Comp and CondFM energize.

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C. Controller Check
1. Controller
Before replacing Controller that does not show a visible defect and that you suspect is bad,
conduct the following check procedure. This procedure will help you verify your
diagnosis. Always choose a neutral to establish a good neutral connection when
checking high voltages. Also, confirm there is a good power supply and neutral connection
to controller: 115VAC at terminals #6 (Brown) to neutral #7 (White).
Alarm Reset: To silence an alarm, press and release the upper or lower button with power
on. For alarm information, see "III.D.Alarm Safeties".
Startup/Cool Down
1) Check that all wiring connections are properly connected.
2) Move the power switch to the "ON" position.
3) Check for 115VAC at terminals #6 (Brown) to neutral #7 (White). If 115VAC is not present,
check power supply, wiring connections, and power switch continuity.
4) Check that the cabinet temperature is displayed on remote display. If not replace the
controller.
5) Check that Comp icon appears in the display and the Comp and CondFM there is
energized. If not, check CTh status. See "II.D.Thermistor Check". If CTh ohm reading is
in proper range, check for 115VAC at terminals #5 (Black Smooth) to neutral #7 (White). If
115VAC is not present, replace controller.
Defrost
6) Manual Defrost Check: Press and hold the snowflake button until "Snow flake icon"
appears on display.
7) Confirm Comp, CondFM de-energize. The EvapFM must be energized during defrost
time.
8) Check that the components restart after defrost termination.
After 25-min of defrost time, the snowflake icon in the display must turn off, and the Comp
icon must be blinking in the display, 3-min. Comp delay timer starts, after the delay timers
terminate the Comp and CondFM energize.
Legend: Comp-compressor; CondFM-condenser fan motor, EvapFM-Evaporator fan
motor, CTh-cabinet thermistor.

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D. Thermistor Check
The cabinet thermistor (NTC type) is used for cabinet temperature control; the thermistor
resistance varies depending on temperature. The controller monitors the thermistors to
control system operation. No adjustment is required; the controller has the adjustment from
factory.
In the event the cabinet thermistor reading is out of range (E0 alarm), the compressor
operates on a fixed time basis of 20-min. on and 15-min. off.
To check thermistor resistance, follow the steps below.
1) Move the power switch to the "OFF" position, then unplug the appliance.
2) Remove the control box cover.
3) Disconnect and remove the thermistor.
4) Check the resistance between the wires at the thermistor. Normal reading is within 10
kΩ at 77°F of ambient.
6) Reconnect and replace the thermistor in its correct position. See "IV.B. Important Notes
for Component Replacement".
7) Plug the appliance back in. Move the power switch to the "ON" position.

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E. Diagnostic Tables
Check for correct appliance installation per the instruction manual and proper voltage per
appliance nameplate.
1. Not Cooling
Not Cooling - Possible Cause
1. Power Supply
a) Unplugged, off, blown fuse, tripped or defective circuit
breaker. On three-section receptacle box, only top
receptacles have power.
b) Loose connection.
c) Not within specifications.
2. Cord and Plug On three-
section model, check
receptacle box cord and
plug and one-section and
two-section cords and
plugs
a) Loose connection.
b) Defective.
3. Power Switch (control
box)
a) "OFF" position.
b) Defective.
4. Wiring
a) Loose connection.
b) Faulty.
5. Controller, See "III.D.
Alarm Safeties" and "II.C.
Controller Check"
a) In alarm or "- - -" shown on display.
b) Defective.
6. Evaporator Fan Motor
a) Defective.
7. Compressor Relay
a) Defective.
8. Compressor Protector
a) Dirty condenser.
b) Condenser fan motor not operating.
c) Compressor capacitor or start relay defective.
d) Defective.
9. Compressor
a) Defective.
10. Condenser
a) Dirty.
11. Evaporator See "II.E.2.
Evaporator Frozen Up"
a) Clogged or frozen.
12. Refrigerant/Refrigerant
Lines
a) Refrigerant leak.
b) Refrigerant lines restricted.

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2. Evaporator Frozen Up
Evaporator Frozen Up - Possible Cause
1. Evaporator
a) Dirty.
2. Evaporator Fan Motor
a) Fan blades binding.
b) Defective.
4. Controller
a) Defective.
5. Compressor Relay
a) Defective.
6. Refrigerant Charge/Refrigerant
Lines
a) Low.
b) Component restriction (cap tube, drier).
3. Defrost: Controller
Refrigerator Defrost Fails to Initiate - Possible Cause
1. Compressor Relay
a) Defective.
2. Controller
a) Defective.
b) Energy loss or restored before the compliance of 6-hr.
Refrigerator Defrost Fails to Terminate - Possible Cause
1. Compressor Relay
a) Defective.
2. Controller
a) Defective.

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NOTICE
• The controller is fragile, handle very carefully.
• Do not change wiring and connections. Never misconnect terminals.
• Do not short out power supply to test for voltage.
Not visible in the controller
Not visible in the controller
Not visible in the controller
III. Controller and adjustments
A. Controller with Integrated Display
1. Controller with Integrated Display
All models are pretested and factory set.
a) Display Icons

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b) Controller Location and Layout
Door to access
condensing unit
and control box.
Controller
Controller
Power Switch
Turn On/Off
Appliance
Lamp Switch
Turn On/Off
The Lamp

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c) Controller Connections
Compressor
Terminals Block
4 & 5
Power Supply
Terminals
Block 6 & 7
Thermistor
Terminals Block
8 & 9
Compressor Icon
Cabinet Temperature
Press to change the temperature
setpoint.
In setpoint mode press to lower
temperature, otherwise press and hold
to initiate manual defrost.
In setpoint mode press to raise temperature,
otherwise press and hold to turn compressor on or
off without unplugging or using power switch.

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B. Temperature
The temperature default scale is °F, but it can be changed to read °C. To change, see
"III.B.3. Changing the Temperature Display Scale (°F or °C)".
1. Default Settings
a) Temperature Setting: 32°F.
b) Temperature Display Scale: °F.
c) Differential temperature: 6°F (3.3°C) to turn ON the Comp and CondFM.
2. Temperature Set Point
The unit comes with a factory default setpoint of 32°F. If setpoint needs to be changed,
follow the steps below.
Press the “SET” button for two seconds. You should see flashing the number 32 (this the
default set point). Release the button.
Press the “UP” or “DOWN” arrows arrows to increase or decrease the set temperature.
Then press the “SET” button to save the new set point.
Note:
The maximum value you can set in the controller is: 36°F.
If you wish to decrease the setpoint, press the DOWN arrow button until you reach the
desired value. Release the button and then press the SET button to keep, and save, the
new value.
Note:
The minimum value you can set in the controller is: 30°F.