Only qualied service technicians should install and service the appliance. To
obtain the name and phone number of your local Hoshizaki Certied Service
Representative, visit www.hoshizaki.com. No service should be undertaken until
the technician has thoroughly read this Service Manual. Failure to service and
maintain the appliance in accordance with this manual will 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.
Hoshizaki provides this manual primarily to assist qualied service technicians in the
service 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.
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.
2
Page 3
IMPORTANT
This manual should be read carefully before the appliance is serviced. Read
the warnings and guidelines contained in this booklet carefully as they provide
essential information for the continued safe use, service, and maintenance of the
appliance. Retain this booklet for any further reference that may be necessary.
CONTENTS
Important Safety Information ................................................................................................. 4
I. Construction and Refrigeration Circuit Diagram ................................................................. 8
A. Construction .................................................................................................................. 8
B. Refrigeration Circuit Diagram ........................................................................................ 9
II. Sequence of Operation and Service Diagnosis ............................................................... 10
A. Sequence of Operation Flow Chart ............................................................................. 10
1. Undercounter and Work Top: Refrigerator .............................................................. 10
3. Undercounter and Work Top: Freezer .................................................................... 37
3
Page 4
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.
DANGER
WARNING
NOTICE
IMPORTANT
Indicates a hazardous situation that, if not avoided, will result in
death or serious injury.
Indicates a hazardous situation that, if not avoided, could result
in death or serious injury.
Indicates a situation that, if not avoided, could result in damage
to the appliance or property.
Indicates important information about the use and care of the
appliance.
DANGER
Risk of Fire or Explosion
Flammable Refrigerant Used
• Follow handling instructions carefully
in compliance with U.S. government
regulations.
• Do not use mechanical devices to defrost.
• Do not puncture refrigerant tubing. Risk
of re or explosion due to puncture
of refrigerant tubing; follow handling
instructions carefully.
• Component parts shall be replaced with
like components.
• Servicing shall be done by factory
authorized service personnel to minimize
the risk of possible ignition due to incorrect
parts or improper service.
• Consult instruction manual/ service
manual before attempting to install or
service this product. All safety precautions
must be followed.
• Dispose of properly in accordance with
federal or local regulations.
• Do not place any potential ignition sources
in or near the appliance.
Risque De Feu Ou D'Explosion
Le Frigorigène Est Inammable
• Suivre attentivement les instructions
de manipulation conformément à la
réglementation gouvernementale.
• Ne pas utiliser d'appareils mécaniques
pour dégivrer le réfrigérateur.
• Ne pas perforer la tubulure contenant le
frigorigène. Risque de feu ou d'explosion
si la tubulure contenant le frigorigène
est perforée; suivre les instructions de
manutention avec soin.
• Les pièces des composants doivent être
remplacées par des pièces et accessoires
équivalents.
• L’entretien doit être effectué par le
personnel de service autorisé par le
fabricant an de minimiser les risques
d’inammation attribuables à l’installation
d’une pièce inadéquate ou à la mauvaise
exécution du service.
• Consulter le manuel du propriétaire/
guide de réparation avant de tenter une
réparation. Toutes les mesures de sécurité
doivent être respectées.
• Éliminer conformément aux règlements
fédéraux ou locaux.
• Ne placez aucune source d’inammation
potentielle dans ou près de l’appareil.
4
Page 5
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 install,
operate, 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 re, follow
basic precautions including the
following:
• Only qualied service technicians should
install and service the appliance.
• Wear appropriate personal protective
equipment (PPE) when servicing the
appliance.
• The appliance must be installed in
accordance with applicable national, state,
and local codes and regulations.
• Appliance is heavy. Use care when lifting
or positioning. Work in pairs when needed
to prevent injury or damage. Do not lift
using the top section or the doors/drawers.
• To reduce the risk of electric shock, do not
touch the plug with damp hands.
• Unplug the appliance before servicing.
• The appliance requires an independent
power supply of proper capacity. See the
nameplate for electrical specications.
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 re.
• THE APPLIANCE MUST BE GROUNDED.The appliance is equipped
with a NEMA5-15 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 qualied electrician replace it with a
properly grounded, independent 3-prong
wall outlet. Do not remove the ground
prong from the power cord and do not use
an adapter plug. Failure to follow these
instructions may result in death, electric
shock, or re.
• Do not use an extension 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 re. To unplug
the appliance, be sure to pull the plug, not
the cord, and do not jerk the cord.
• The GREEN ground wire in the factoryinstalled power cord is connected to the
appliance. If it becomes necessary to
remove or replace the power cord, be
sure to connect the power cord's ground
wire.
• 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, re, 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.
5
Page 6
WARNING, continued
• Children should be properly supervised
around the appliance.
• Do not climb, stand, or hang on the
appliance or doors/drawers 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 ngers when
opening and closing the doors/drawers
or rail cover (prep table models) or when
handling food pans. Be careful when
opening and closing the doors/drawers or
rail cover when children are in the area.
• Open and close the doors/drawers and
rail cover (prep table models) with care.
Opening the doors/drawers or rail cover
too quickly or forcefully may cause
injury or damage to the appliance or
surrounding equipment.
• Do not use combustible spray or place
volatile or ammable substances in or
near the appliance. They might catch re.
• Keep the area around the appliance clean.
Dirt, dust, or insects in the appliance
could cause harm to individuals or
damage to the equipment.
• 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
ow. Also allow space between items and
interior surfaces.
• Do not put warm or hot foods in the cabinet.
Let them cool rst, or they will raise the
cabinet temperature and could deteriorate
other foods in the cabinet or overload the
appliance.
• Food storage and handling must comply with
applicable codes and regulations.
• All foods should be wrapped in plastic lm
or stored in sealed containers. Otherwise
foods may dry up, pass their smells onto
other foods, cause frost to develop, result in
poor appliance performance, or increase the
likelihood of cross-contamination. Certain
dressings and food ingredients, if not
stored in sealed containers, may accelerate
corrosion of the evaporator, resulting in
failure.
• Do not store items near air outlets.
Otherwise, items may freeze up and
crack or break causing a risk of injury or
contamination of other food.
• Do not throw anything onto the shelves
or load any single shelf with more than
120lb. (54.5 kg) of product. They might fall
off and cause injury.
• Do not load any single drawer with more
than 75 lb. (34 kg) of product. Depending
on the weight of product in the drawers,
secure the unit as necessary to prevent it
from overturning. Do not open more than
one drawer at a time.
• 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.
6
Page 7
WARNING, continued
Additional Warnings for Prep Table
Models
• The entire rail must always be covered
by rail dividers and pans (1/6 size, up
to 6"(15cm)deep). Otherwise, the
appliance will not cool properly.
• Use only 1/6 size pans up to 6"(15cm)
deep. Do not use damaged pans.
• Ingredients must be pre-chilled to 37°F
(3°C) or less before placing in rail.
• Keep the rail cover closed when not
actively preparing food.
NOTICE
• Protect the oor when moving the
appliance to prevent damage to the oor.
• Keep ventilation openings, in the
appliance enclosure or in the built-in
structure, clear of obstruction. Do not
place anything on top of the appliance in
an undercounter installation. There must
be at least 1.5" (4 cm) overhead clearance
for proper ventilation. The factory-installed
rear bumpers must be in place to ensure
proper rear clearance. Blockage of airow
could negatively affect performance and
damage the appliance.
• The rail is for keeping ingredients cool
while preparing food. If not actively
preparing food for a long period such
as overnight, seal pans with plastic
wrap in addition to closing the rail cover.
Depending on conditions, the cabinet
temperature setting may need to be
adjusted to prevent items from freezing.
Alternatively, seal ingredients and store
them in a refrigerator or freezer.
• Do not allow the appliance to bear any
outside weight.
• 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/drawer 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.
Additional Notice for Prep Table
Models
• Do not place anything on top of the rail
hood or rail cover and do not lift the
appliance by the rail hood or rail cover.
The rail hood and rail cover are not
designed to bear any outside weight.
7
Page 8
I. Construction and Refrigeration Circuit Diagram
A. Construction
1. Undercounter, Worktop, Prep Table Common Parts
• Evaporator
• Evaporator Fan
• Evaporator Fan Shroud
Nameplate
Thermometer
Door
Rear Panel
Control Module
Cover
Cabinet Temperature Control Dial
Model Shown: UF60A
Control
Module
Compressor
Door Gasket
Condenser
Condenser Fan Motor
Model Shown: UF60A
8
Page 9
B. Refrigeration Circuit Diagram
Condenser
High-Pressure Switch
Capillary Tube
Condenser Fan
Evaporator Fans
(1, 2, or 3 depending on model)
Drier
Compressor
Evaporator
Prep Table and Freezer Models: Defrost Heater, Defrost Safety Thermostat, and Defrost Thermistor
Cabinet Thermostat Bulb
9
Page 10
II. Sequence of Operation and Service Diagnosis
The steps in the sequence are as outlined below.
See the table for default cabinet temperature control settings.
Legend:
Comp-compressor
ConFM-condenser fan motor
CTh-cabinet thermistor
EvapFM-evaporator fan motor
Note: Delays
*
a) 2-min. minimum Comp on timer starts when Comp energizes.
b) 2-min. minimum Comp off timer starts when Comp de-energizes.
10
Page 11
2. Prep Table: Refrigerator
5. Defrost Termination
Defrost Termination:
46°F (7.7°C) achieved or
45 min. backup defrost
timer terminated.
Evap. temp. below
50°F (10°C)
4. Defrost
6-hr. DT terminates
Defrost:
Time/Temp achieved.
DTh in control
setpoint
CTh above
Defrost
Evap. Temp.
Terminated
reaches 46°F (7.7°C)
DH de-energized
*
6-hr DT starts
After DOT Delay:
Comp energized
ConFM energized
After FDD
*
EvapFM energized
*
*
6-hr. DT terminates
5-min. min. DT starts
45-min. max. DT starts
DH energized
Comp de-energized
ConFM de-energized
EvapFM de-energized
*
2-min. Comp off
3. Cool Down Achieved
CTh cools to setpoint
timer starts
EvapFM energized
Comp de-energized
CTh in control
ConFM de-energized
Prep Table Top Sequence Flow Chart
*
*
2-min. Comp on
2. Cool Down
1. Startup
CTh above setpoint
Red LED Off
Green LED Flashes
timer starts
If Red LED Flashes,
check CTh or DTh
Comp energized
EvapFM energized
ConFM energized
EvapFM energized
a) 2-min. minimum Comp on timer starts when Comp energizes.
b) 2-min. minimum Comp off timer starts when Comp de-energizes.
c) 5-min. minimum defrost time.
d) 45-min. maximum defrost time.
e) DOT (drip off time) 1-min. Comp/ConFM delay timer starts when defrost termination temperature is met (drip off time (DOT)).
f) FDD (fan delay after defrost) EvapFM starts once 30-sec. EvapFM delay timer terminates or DTh reaches 40°F (4.4°C).
Note: Delays
g) If evaporator temperature raises above 50°F (10°C) during the cooling cycle, 6-hr. DT resets.
Power on
Red LED On
(5 sec. Delay)
11
Legend:
Comp-compressor
ConFM-condenser fan motor
CTh-cabinet thermistor
DH-defrost heater
DT-defrost timer
DTh-defrost thermistor
EvapFM-evaporator fan motor
Page 12
3. Undercounter and Work Top: Freezer
Defrost
5. Defrost Termination
Defrost Termination:
50°F (°10C) achieved or
1 hr. backup defrost timer
terminated.
DH de-energized
DTh in control
Terminated
8-hr. DT starts
*
After DOT Delay:
Comp energized
ConFM energized
MH energized
PH energized
*
After FDD
EvapFM energized
Defrost Initiation:
3. Defrost
Time/Temp achieved.
CTh warms
above
setpoint
8-hr. DT terminates
Evap. temp. below 41°F (5°C)
8-hr. DT terminates
Evap. temp. below 41°F (5°C)
5-min. min. DT starts
60-min. max. DT starts
DH energized
Comp de-energized
ConFM de-energized
EvapFM de-energized
PH de-energized
MH de-energized
Freezer Sequence Flow Chart
2. Cool Down Achieved
Achieved
2-min. Comp off
timer starts
Comp de-energized
ConFM de-energized
EvapFM de-energized
MH de-energized
PH de-energized
Setpoint
*
CTh in control
a) 2-min. minimum Comp on timer starts when Comp energizes.
b) 2-min. minimum Comp off timer starts when Comp de-energizes.
c) 5-min. minimum defrost time.
d) 1-hr. maximum defrost time.
e) DOT (drip off time) 3-min. Comp/ConFM delay timer starts when defrost termination temperature is met (drip off time (DOT)).
f) FDD (fan delay after defrost) EvapFM starts once 7-min. EvapFM delay timer terminates or DTh reaches 25°F (-4°C).
1. Startup/Cool Down
Red LED off
Green LED Flashes
If Red LED ashes,
check CTh or DTh
6-hr. or 8-hr. DT starts
2-min. Comp on
timer starts
Note: Delays
Comp energized
Power on
Red LED On
(5 sec. Delay)
ConFM energized
EvapFM energized
MH energized
PH energized
12
Legend:
Comp-compressor
ConFM-condenser fan motor
CTh-cabinet thermistor
DH-defrost heater
DT-defrost timer
DTh-defrost thermistor
EvapFM-evaporator fan motor
MH-mullion heater
PH-perimeter heater
Page 13
B. Service Diagnosis
DANGER
Risk of Fire or Explosion
Flammable Refrigerant Used
• Follow handling instructions carefully
in compliance with U.S. government
regulations.
• Do not use mechanical devices to defrost.
• Do not puncture refrigerant tubing. Risk
of re or explosion due to puncture
of refrigerant tubing; follow handling
instructions carefully.
• Component parts shall be replaced with
like components.
• Servicing shall be done by factory
authorized service personnel to minimize
the risk of possible ignition due to
incorrect parts or improper service.
• Consult instruction manual/service manual
before attempting to install or service this
product. All safety precautions must be
followed.
• Dispose of properly in accordance with
federal or local regulations.
• Do not place any potential ignition sources
in or near the appliance.
Risque De Feu Ou D'Explosion
Le Frigorigène Est Inammable
• Suivre attentivement les instructions
de manipulation conformément à la
réglementation gouvernementale.
• Ne pas utiliser d'appareils mécaniques
pour dégivrer le réfrigérateur.
• Ne pas perforer la tubulure contenant le
frigorigène. Risque de feu ou d'explosion
si la tubulure contenant le frigorigène
est perforée; suivre les instructions de
manutention avec soin.
• Les pièces des composants doivent être
remplacées par des pièces et accessoires
équivalents.
• L’entretien doit être effectué par le
personnel de service autorisé par le
fabricant an de minimiser les risques
d’inammation attribuables à l’installation
d’une pièce inadéquate ou à la mauvaise
exécution du service.
• Consulter le manuel du propriétaire/
guide de réparation avant de tenter une
réparation. Toutes les mesures de sécurité
doivent être respectées.
• Éliminer conformément aux règlements
fédéraux ou locaux.
• Ne placez aucune source d’inammation
potentielle dans ou près de l’appareil.
WARNING
• The appliance should be diagnosed and repaired only by qualied service
personnel to reduce the risk of death, electric shock, serious injury, or re.
• Wear appropriate personal protective equipment (PPE) when servicing the
appliance.
• 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.
• Appliance is heavy. Use care when lifting or positioning. Work in pairs when
needed to prevent injury or damage.
• Make sure all food zones are clean after the appliance is serviced.
13
Page 14
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.
See the table for default cabinet temperature control settings.
ModelDefault Cabinet Temperature
Control Setting
Undercounter
Worktop
Prep TableBetween 4 and 534°F (1°C)
Between 4 and 5Refrigerator: 34°F (1°C)
Approximate Default Temperature
Freezer: -5°F (-21°C)
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.
Conrm that the appliance location meets factory requirements:
• This appliance is not intended for outdoor use. Normal operating ambient
temperature should be within 45°F to 86°F (7°C to 30°C).
• The appliance should not be located next to ovens, grills, or other high heat
producing equipment. Check CM using the steps in "II.C. Control Module Check."
Note: • When checking voltage (115VAC), always choose a neutral white (W) wire to
establish a good neutral connection.
• CM has high and low voltage protection. If off on either protection, no LED is
visible and all components are off.
High Voltage: 135VAC
Low Voltage: 90VAC
• Solid red LED for 5 sec. at startup.
• Flashing green LED: Normal operation.
• Flashing red LED: check cabinet thermistor and defrost thermistor (if applicable).
• CM has a 2 min. minimum on time and 2 min. minimum off time for Comp.
1) Unplug the appliance from the electrical outlet.
2) Remove the rear panel.
3) Plug the appliance back into the electrical outlet. If appliance was in defrost when power
supply was disconnected, defrost is terminated and normal cooling cycle begins when
power supply is reconnected.
4) Startup/Cool Down–There is a slight delay (solid red LED for 5 sec., then ashing
green LED). Temperature above setpoint at CTh and if applicable, conrm appliance is
not in a defrost cycle (PT and Freezers). Comp, CondFM, and EvapFM energize. 2-min.
Comp on timer starts.
Freezers: PH, and MH energize.
a) CTh Diagnosis: If CTh fails, a red LED ashes along with the green LED on the CM.
Conrm CTh is properly connected to CM. Check Ohm reading of CTh. Replace as
needed.
b) TD Diagnosis: Conrm TD is set between 4 and 5. Check Ohm reading of TD.
Replace as needed.
14
Page 15
c) CM Diagnosis: Conrm green LED is ashing. If not, check for 115VAC between
CM 2 (L) black (BK) wire and CM 3 (N) neutral white (W) wire. If 115VAC is
not present, check power cord connections and breaker/fuse. Conrm wiring
connections are secure for both CM 2 (L) black (BK) (power supply) and CM 3 (N)
white (W) (neutral).
If 115VAC is present and green LED is not ashing, replace CM.
d) Comp/CondFM Diagnosis: Check that Comp and ConFM energize. If not, conrm
that the temperature is above setpoint. Next, check for 115VAC at CM 1 (C)
brown(BR) wire to neutral white (W) wire. If 115VAC is not present, replace CM.
If 115VAC is present, check HPS continuity (if applicable). See "f) HPS Activation"
below.
Comp: If 115VAC is present, check Comp external overload, start cap, start relay,
and Comp motor windings. Replace as needed.
CondFM: If 115VAC is present, check fan blade for binding, then check ConFM
motor windings.
e) EvapFM Diagnosis: Check that EvapFM(s) energize. If not, check for 115VAC at
CM 5 (F) dark blue (DBU) wire to neutral white (W) wire. If 115VAC is not present,
replace CM. If 115VAC is present, check fan blades for binding, then check EvapFM
motor windings.
f) HPS Activation: Check continuity of HPS. If open, allow time for system pressure
to equalize and HPS to reset. If HPS does not reset, replace HPS and diagnose
reason for HPS activation. Conrm ConFM is energized and fan blade turns freely.
Check that the condenser coil is not clogged or restricted. Check that there are no
restrictions in the refrigeration circuit (drier).
g) PH and MH Diagnosis (Freezer only): PH and MH follow Comp operation. When
Comp is energized, PH and MH are energized. If 115VAC is present, check amp
draw of PH and MH. If an amp reading is not present, check the continuity of PH
and MH. If defective, replace PH or MH.
If Comp, ConFM, and EvapFM are energized and the cabinet does not cool down,
check for a restriction in the refrigeration circuit, low refrigerant charge, or inefficient
Comp.
5) Cool Down Achieved–Temperature cools to setpoint. Comp and ConFM de-energize.
UC/WT Refrigerators and Freezers: EvapFM de-energizes.
Prep Table: EvapFM continues.
Diagnosis: If temperature setpoint achieved and Comp, ConFM, and EvapFM(except
PT models) does not de-energize, check CTh and TD continuity. If CTh or TD is
defective, replace. If CTh and TD are good and either the Comp, ConFM, and/or
EvapFM (except PT models) continue, or if EvapFM on PT models de-energizes,
replace CM.
15
Page 16
6) Defrost–Manually initiated defrost, off cycle defrost, and time-initiated
temperature-terminated heated defrost.
1a) Manually-Initiated (All): Turn the TD all the way to the right. Wait 1 to 3 sec. then
back to original setting. Defrost initiated. If defrost does not initiate, wait 1 to 2 min.
and repeat process.
1b) Off Cycle-Initiated (UC/WT Refrigerators): Off cycle between cooling cycles.
5-min. minimum DT starts and 1-hr maximum DT starts.
Note: When DTh is above 50°F (10°C) on Prep Tables or above 41°F (5°C) on
Freezers, defrost will not initiate and Prep Table 6-hr. DT and Freezer 8-hr.
DT resets and starts once DTh temperature cools below 50°F (10°C)on Prep
Tables or cools below 41°F (5°C) on Freezers.
2a) Manually-Terminated: Turn the TD all the way to the right. Wait 1 to 3 sec. then
back to original setting. Defrost terminated. If DH continues or Comp does not
energize, make several more attempts of manual termination.
2c) Temperature or Time-Terminated: DTh achieves termination temperature or
backup DT terminates.
(1) Prep Tables: 46
°F (7.7°C) achieved or 45-min. backup DT terminates. DH
de-energizes. IfCTh calling for cooling, 1-min. Comp delay timer starts (drip time)
and 90-sec. EvapFM delay timer starts. 1-min. Comp delay timer terminates.
Comp and ConFM energize. 30 sec. later, 90-sec. EvapFM delay timer
terminates and EvapFM energizes.
Note: If DTh achieves 40°F before 90-sec. EvapFM delay timer terminates,
90-sec. EvapFM delay timer terminates and EvapFM energizes.
(2) Freezers: 50°F (10°C) achieved or 1-hr. DT terminates. DH de-energizes. If CTh
calling for cooling, 3-min. Comp delay timer starts (drip time) and 7-min. EvapFM
delay timer starts. 3-min. Comp delay timer terminates. Comp and ConFM
energize. 4min. later, 7-min. EvapFM delay timer terminates and EvapFM
energizes.
Note: If DTh achieves 25°F before 7-min. EvapFM delay timer terminates, 7-min.
EvapFM delay timer terminates and EvapFM energizes.
16
Page 17
Defrost Diagnosis:
1) Manual-Initiation: TD rotated to max. position and back. Prep Table 6-hr. DT or
Freezer 8-hr. DT terminates. After rotating TD several times and defrost still not
activated, wait 1 to 2 min. and repeat process. Replace TD as needed.
(2) CM Diagnosis: Conrm DH energizes (if applicable) and Comp, ConFM, and
EvapFM (if applicable) de-energize. If not, replace CM.
(3) Comp and ConFM Diagnosis: Conrm Comp and ConFM de-energize. If not,
check for 115VAC at CM 1 (C) (BR) to neutral (W). If 115VAC is present, Check
DTh continuity. Replace as needed. If DTh conrmed, replace CM.
(4) EvapFM (if applicable): Conrm EvapFM de-energizes. If not, check for 115VAC
at CM 5 (F) (DBU) to neutral (W). If 115VAC is present, conrm Comp and
ConFM de-energized. Next, check DTh continuity. Replace as needed. If DTh
conrmed, replace CM.
2) Off Cycle Defrost: Off cycle defrost. Has CTh warmed above temperature setpoint?
Ifnot, conrm CTh continuity. Replace as needed. If CTh conrmed, replace CM.
3) Heated Defrost Diagnosis: Initiation; Conrm Comp is energized, then manually
initiate defrost. Rotate TD all the way to the right. Wait 1 to 5sec. then rotate back
to original setting. Defrost initiated.
a) Prep Table: Check that Comp and ConFM de-energize. DH energizes.
EvapFMcontinues.
b) Freezer: Check that Comp, ConFM, PH, MH, and EvapFM de-energize.
DHenergizes.
(1) TD: If Comp and ConFM continue, wait 1 to 2 min. and make several more
attempts of manual initiation. Ifmanual initiation fails, replace TD.
(2) CM: If TD conrmed and Comp and ConFM continue, replace CM.
(3) DH: If Comp and ConFM de-energize, check that DH energizes. Check for
115VAC at CM 4 (H) (R) to CM 3 (N) (W). If 115VAC is not present, replace CM.
If115VAC is present, and DH is not energized, check for 115VAC at DST black
(BK) wire to any neutral white (W) wire. If 115VAC is not present, DST is open.
Letcool and reset. If DST does not reset (close), replace DST. If 115VAC is
present, check continuity of DH. Replace as needed.
4) Heated Defrost Diagnosis: Termination;
a) Prep Table
(1) DTh: DTh warms to 46°F (7.7°C). DH de-energizes. Conrm continuity of DTh.
Replace as needed. If DTh is good and DH continues after DTh achieves 46°F
(7.7°C), replace CM.
b) Freezer
(1) DTh: DTh warms to 50°F. (10°C) DH de-energizes. Conrm continuity of DTh.
Replace as needed. If DTh is good and DH continues after DTh achieves 50°F
(10°C), replace CM.
Legend: Comp–compressor; ConFM–condenser fan motor; CM–control module;
Before replacing a CM 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 (W) to establish a good power supply and neutral connection to
CM: 115VAC at CM 2 (L) (BK)
2. Startup/Cool Down
At startup, CM displays a solid red LED for 5 sec. After 5 sec. CM turns red LED off and
begins ashing a green LED. This is normal operation. If a red LED ashes (fault code),
check CTh or DTh for continuity and good connection to CM.
1) Check all wiring connections.
2) Be sure the power supply is connected to the electrical outlet.
3) Conrm the CTh and DTh are properly connected (no red LED ashing). A Red LED
turns on for 5 sec. at startup. After 5 sec. the red LED turns off and a green LED starts
ashing. This is normal operation. If the red LED starts ashing, check CTh and DTh
continuity. Replace as needed.
4) Check that Comp, ConFM, and EvapFM energize (PH and MH on freezers). If not check
CTh status. If CTh ohm reading is in proper range,
Comp and ConFM and PH and MH (freezers); check for 115VAC at CM 1 (C) (BR)
to neutral white (W). If 115VAC is not present, replace CM. If 115VAC is present and
Comp energized and ConFM did not, check ConFM blades for binding and motor
winding continuity. If PH or MH (freezers) does not energize, check continuity, replace
as needed.
EvapFM; Check for 115VAC at CM 5 (F) (DBU) to neutral white (W). If 115VAC is not
present, replace CM. If115VAC is present, check EvapFM blades for binding and motor
winding continuity.
3. Defrost initiation
5) Manual Defrost Check: Turn the TD all the way to the right. Wait 1 to 3 sec. then back
to original setting. Defrost initiated. If Comp and ConFM continue, wait 1 to 2 min. and
repeat process of manual initiation. If Comp remains energized, replace CM.
6) Conrm Comp, ConFM, EvapFM (UC/WT refrigerator and freezer), PH and MH
(freezers) de-energize. If not, for Comp, ConFM and PH and MH (freezers), check for
115VAC at CM 1 (C) (BR) to neutral white (W) wire and for EvapFM (if applicable) CM
5 (F) (DBU) to neutral white wire (W). If 115VAC is present, replace CM. Note: EvapFM
continues on Prep Table models.
7) Heated Defrost: Conrm DH energizes. Check for 115VAC at CM 4 (H) (R) to neutral
white (W) wire. If 115VAC is not present, replace CM.
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4. Defrost Termination
8) Check that all components restart after defrost termination.
a) UC/WT Refrigerator: CTh above setpoint. Cool cycle starts. Comp, ConFM, and
EvapFM energize.
b) Prep Table: DTh warms to 46°F (7.7°C). DH de-energizes. Conrm continuity of DTh.
Replace as needed. If DTh is good and DH continues after DTh achieves
46°F (7.7°C), replace CM.
c) UC/WT Freezer: DTh warms to 50°F (10°C). DH de-energizes. Conrm continuity of
DTh. Replace as needed. If DTh is good and DH continues after DTh achieves 50°F
(10°C), replace CM.
Legend: Comp–compressor; ConFM–condenser fan motor; CM–control module;
Before consulting the diagnostic tables, check the following:
• Check the cabinet temperature control setting. See the table for default cabinet
temperature control settings.
ModelDefault Cabinet Temperature
Control Setting
Undercounter
Worktop
Prep TableBetween 4 and 534°F (1°C)
Between 4 and 5Refrigerator: 34°F (1°C)
Approximate Default Temperature
Freezer: -5°F (-21°C)
• Make sure the doors are not left open or opened too often and that they are sealing
properly.
• On prep tables, pans and rail dividers must be in place. Otherwise, the rail will not cool
properly.
• Make sure product is not blocking airow and that the cabinet is not overloaded with
warm or hot product. Product should be allowed to cool before putting in the appliance.
On prep tables, only load ingredients that have been pre-chilled to 37°F (3°C) or less.
• Check for correct installation and proper voltage per appliance nameplate. This
appliance is not intended for outdoor use. Normal operating ambient temperature:
– Undercounter and Worktop 45°F to 100°F (7°C to 38°C)
– Prep Table 45°F to 86°F (7°C to 30°C)
• The appliance should not be located next to ovens, grills, or other high heat producing
equipment. A minimum of 1.5" (38 mm) overhead clearance is required for proper
ventilation.
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1. Appliance Not Cooling
Appliance Not Cooling - Possible Cause
Power Supply
1.
Power Supply Cord and Plug
2.
Wiring
3.
Cabinet Thermostat or Cabinet
4.
Thermistor
Cabinet Temperature Dial
5.
Defrost Timer or Control Module
6.
(if applicable)
Evaporator Fan Motor
7.
Condenser Fan Motor
8.
Compressor External Protector
9.
Compressor
10.
Condenser
11.
Evaporator
12.
Refrigerant/Refrigerant Lines
13.
High-Pressure Switch
10.
(if applicable)
Thermostatic Expansion Valve
11.
(not adjustable)
Unplugged, blown fuse, or tripped or defective circuit breaker.
a)
Loose connection.
b)
Not within specications.
c)
Loose connection.
a)
Defective.
b)
Loose connection or open.
a)
Faulty.
b)
Loose, disconnected, or defective.
a)
Loose, disconnected, or defective.
a)
Defrost timer defective. If applicable.
a)
Control module in alarm (red LED ashing). If applicable.
b)
Control module defective. If applicable.
c)
Defective.
a)
Fan blade binding.
b)
Defective.
a)
Fan blade binding.
b)
Dirty condenser.
a)
Condenser fan motor not operating.
b)
Defective.
c)
Start relay defective.
d)
Low charge.
e)
Start capacitor (if applicable) defective.
f)
Defective.
a)
Dirty.
a)
Dirty or frozen up.
a)
Gas leak.
a)
Refrigerant lines or components restricted.
b)
Dirty condenser.
a)
Ambient temperature too warm.
b)
Condenser fan motor not operating.
c)
Refrigerant overcharge.
d)
Refrigerant lines or components restricted.
e)
Bad contacts.
f)
Defective.
a)
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2. Evaporator is Frozen Up
Evaporator is Frozen Up - Possible Cause
Evaporator
1.
Evaporator Fan Motor
2.
Refrigerant Charge
3.
Defrost Heater (if applicable)
4.
Defrost Timer or Control Module
5.
(if applicable)
Defrost Safety Thermostat Open
6.
(if applicable)
Thermostatic Expansion Valve
7.
(not adjustable)
Dirty.
a)
Defective.
a)
Fan blade binding.
b)
Low.
a)
Defective.
a)
Defective.
a)
Defective.
a)
Defective.
a)
3. Defrost Fails to Initiate or Terminate
Defrost Fails to Initiate or Terminate - Possible Cause
Defrost Thermistor (if applicable)
1.
Defrost Timer or Control Module
2.
(if applicable)
Defrost Heater (if applicable)
3.
Defective.
a)
Defective.
a)
Defective
a)
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Page 23
III. Controls and Adjustments
A. Temperature Settings
1. Temperature Reading
A thermometer with both °F and °C scales is mounted in the cabinet. See Fig. 1.
2. Cabinet Temperature
The appliance features a cabinet temperature control dial (TD). The warmest setting
is 1and the coldest setting is 7. See the table for default cabinet temperature control
settings.
ModelDefault Cabinet Temperature
Control Setting
Undercounter
Worktop
Prep TableBetween 4 and 534°F (1°C)
Between 4 and 5Refrigerator: 34°F (1°C)
Approximate Default Temperature
Freezer: -5°F (-21°C)
Fig. 1
WarmerColder
Cabinet Temperature
Control Dial
B. Defrost
There are 2 types of defrost: Off Cycle Defrost and Heated Defrost.
Manual Initiation (All Models): Turn the TD all the way to the right. Wait 3 sec. then
back to original setting. Defrost initiated.
Refrigerator Off Cycle Defrost Automatic Initiation: Compressor cycles off with
cabinet setpoint temperature achieved.
Heated Defrost Automatic Initiation: Temperature achieved and defrost timer
terminates.
Manual Termination: Turn the TD all the way to the right. Wait 3 sec. then back to
original setting. Defrost terminated.
Automatic Termination: Cabinet temperature above setpoint, or defrost thermistor
above termination temperature, or backup defrost timer terminates.
Thermometer
1. Undercounter and Worktop Refrigerators
Off-Cycle Defrost: Undercounter and worktop refrigerators defrost naturally between run
cycles.
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2. Prep Table and Freezer
Temperature/Time-Initiated Defrost Cycle: Defrost cycle occurs once every 6hrs. for prep
tables or 8 hrs. for freezers when defrost initiation temperature achieved (50
Prep Tables or 41
°F (5°C) for the Freezers). Defrost cycle initiation and termination are
°F (10°C) for
controlled by the control module and defrost thermistor.
Prep Table Refrigerators: The defrost heater energizes, the evaporator fan motor
remains energized, and all other components de-energize during the defrost cycle.
There is an in-line defrost safety thermostat.
Freezers: The defrost heater energizes and all other components de-energize during the
defrost cycle. There is an in-line defrost safety thermostat.
Minimum Defrost Time is 5 min.
Maximum Defrost Time is 45 min. for Prep Tables and 1 hr. for Freezers.
To initiate a manual defrost cycle follow the steps below.
1) Rotate TD all the way to the right. Wait 1 to 5sec. then rotate back to original setting.
Defrost initiated. See Fig. 2.
2) Repeat step 1 to terminate defrost.
Fig. 2
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Page 25
C. Safety Devices
1. Compressor External or Internal Protector (All Models)
If combined temperature/amperage value is above the limit specied by the
compressor manufacturer, the compressor protector operates independently to turn
off the compressor. The compressor protector de-energizes the compressor until the
temperature/amperage value returns to an acceptable level.
2. High-Pressure Switch
If pressure on the high-side of the appliance exceeds Hoshizaki specications, the
high-pressure switch activates and interrupts the compressor circuit, de-energizing the
compressor until the pressure returns to an acceptable level.
If the condenser fan motor is operating and the compressor is off, it is most likely that the
compressor protector opened. If both the compressor and condenser fan motor are off, it
is most likely the appliance is off or the high-pressure switch has opened.
D. Perimeter and Mullion Heaters
Freezers are equipped with perimeter and mullion heaters. If condensation occurs,
check continuity of heaters.
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Page 26
IV. Refrigeration Circuit and Component Service Information
DANGER
Risk of Fire or Explosion Flammable Refrigerant Used
• Follow handling instructions carefully in compliance with U.S. government
regulations.
• Do not use mechanical devices to defrost.
• Do not puncture refrigerant tubing. Risk of re or explosion due to puncture of
refrigerant tubing; follow handling instructions carefully.
• Component parts shall be replaced with like components.
• Servicing shall be done by factory authorized service personnel to minimize the risk
of possible ignition due to incorrect parts or improper service.
• Consult instruction manual/service manual before attempting to install or service
this product.
• Dispose of properly in accordance with federal or local regulations.
• Do not place any potential ignition sources in or near the appliance.
Risque De Feu Ou D'Explosion Le Frigorigène Est Inammable
• Suivre attentivement les instructions de manipulation conformément à la
réglementation gouvernementale.
• Ne pas utiliser d'appareils mécaniques pour dégivrer le réfrigérateur.
• Ne pas perforer la tubulure contenant le frigorigène. Risque de feu ou d'explosion
si la tubulure contenant le frigorigène est perforée; suivre les instructions de
manutention avec soin.
• Les pièces des composants doivent être remplacées par des pièces et accessoires
équivalents.
• L’entretien doit être effectué par le personnel de service autorisé par le fabricant
an de minimiser les risques d’inammation attribuables à l’installation d’une pièce
inadéquate ou à la mauvaise exécution du service.
• Consulter le manuel du propriétaire/guide de réparation avant de tenter une
réparation. Toutes les mesures de sécurité doivent être respectées.
• Éliminer conformément aux règlements fédéraux ou locaux.
• Ne placez aucune source d’inammation potentielle dans ou près de l’appareil.
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Page 27
WARNING
• Wear appropriate personal protective equipment (PPE) when servicing the
appliance.
• Technician must utilize a combustible gas leak detector at all times.
• Notify everyone in the immediate area that you are working with ammable
refrigerant.
• Do not work on appliance in a conned space. Conrm area is well ventilated.
• Identify and eliminate all possible ignition points in a 10 ft. (3 m) area around service
area.
• Do not use mechanical devices to defrost.
• Use non-sparking tools.
• Class B dry chemical re extinguisher or equivalent must be available.
• Do not pressurize system above 200 PSIG during leak check procedure or prior to
evacuating refrigeration system.
• This appliance should be diagnosed and repaired only by qualied service
personnel to reduce the risk of death, electric shock, serious injury, or re.
• To reduce the risk of electric shock, do not touch the plug with damp hands.
• Unplug the appliance from the electrical outlet before servicing.
• Make sure all food zones in the appliance are clean after the appliance is
serviced.
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A. Refrigeration Circuit Service Information
WARNING
• Repairs requiring the refrigeration circuit to be opened must be performed by
properly trained and EPA-certied service personnel.
• Use an electronic leak detector or soap bubbles to check for leaks. Add a trace
of refrigerant to the system (if using an electronic leak detector), and then raise
the pressure using nitrogen gas (140 PSIG). Do not use R-290 as a mixture with
pressurized air for leak testing.
NOTICE
• Always recover the refrigerant and store it in an approved container. Do not
discharge the refrigerant into the atmosphere.
• Do not leave the system open for longer than 15 minutes when replacing or
servicing parts. The Polyol Ester (POE) oils used in R-290 appliances can absorb
moisture quickly. Therefore it is important to prevent moisture from entering the
system when replacing or servicing parts.
• Always install a new drier every time the sealed refrigeration system is opened.
Do not replace the drier until after all other repair or replacement has been made.
Install the new drier with the arrow on the drier in the direction of the refrigerant
ow.
• When brazing, protect the drier by using a wet cloth to prevent the drier from
overheating. Do not allow the drier to exceed 250°F (121°C).
Refrigerant leaks must be repaired as soon as they are discovered. If not, refrigerant
charge should be recovered from the system until the leak can be repaired.
When repairing a leak:
• Repair the leak properly – Remove the refrigerant, examine the leak source, determine
the reason for the leak, and carry out the proper course of action.
• Before repairing the leak, ensure that the refrigerant has been recovered and the
system purged with nitrogen when brazing.
• Be sure to remove piercing valves attached to the system after repairs are made.
1. Refrigerant Recovery
Using proper refrigerant practices, place piercing valves toward the end (crimped area)
of the high and low-side process tubes, then recover the refrigerant into an approved
container or device.
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Page 29
2. Brazing
DANGER
Risk of Fire or Explosion Flammable Refrigerant Used
• Servicing shall be done by factory authorized service personnel to minimize the risk
of possible ignition due to incorrect parts or improper service.
Risque De Feu Ou D'Explosion Le Frigorigène Est Inammable
• L’entretien doit être effectué par le personnel de service autorisé par le fabricant
an de minimiser les risques d’inammation attribuables à l’installation d’une pièce
inadéquate ou à la mauvaise exécution du service.
WARNING
• Wear appropriate personal protective equipment (PPE) when servicing the
appliance.
• You must have a combustible gas leak detector in the immediate work area at all
times.
• You must have a Class B chemical re extinguisher available at all times.
• Notify all persons in the immediate area that you are working with a ammable
refrigerant.
• Do not use silver alloy or copper alloy containing arsenic.
• Be sure the area is clear of refrigerant vapor before brazing.
1) Braze/repair/replace damaged component or tting.
2) Purge with nitrogen gas for 2 min. Then braze all ttings while purging with nitrogen gas
owing at a pressure of 3 to 5 PSIG.
NOTICE
• Always install a new drier every time the sealed refrigeration system is opened.
• Do not replace the drier until after all other repair or replacement has been made.
Install the new drier with the arrow on the drier in the direction of the refrigerant
ow.
• When brazing, protect the drier by using a wet cloth to prevent the drier from
overheating. Do not allow the drier to exceed 250°F (121°C).
3) Use soap bubbles to check for leaks. Raise the pressure using nitrogen gas (190 PSIG).
Do not use any refrigerant as a mixture with pressurized air for leak testing.
4) Once leak checking is complete, release the nitrogen gas from the system.
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Page 30
3. Evacuation
1) Attach a vacuum pump to the system. Be sure to connect the charging hoses to both
high and low-side refrigerant piercing valves.
IMPORTANT
The vacuum level and vacuum pump may be the same as those for current
refrigerants. However, the rubber hose and gauge manifold to be used for
evacuation and refrigerant charge should be exclusively for POE oils.
2) Turn on the vacuum pump, then open the gauge manifold valves. Never allow the oil in
the vacuum pump to ow backwards.
3) Allow the vacuum pump to pull down to a 29.9" Hg vacuum (500 microns). Evacuating
period depends on pump capacity.
4) Close the low-side valve and high-side valve on the gauge manifold.
5) Disconnect the gauge manifold hose from the vacuum pump and attach it to a
refrigerant service cylinder. Remember to loosen the connection and purge the air
from the hose. For the required refrigerant charge, see the nameplate. Hoshizaki
recommends only virgin or reclaimed refrigerant which meets ARI Standard 700 (latest
edition) be used.
4. Recharge
6) R-290 can be charged in either the liquid or vapor state.
Liquid charge is preferred. Ifrefrigerant charging is done in the liquid state, place the
service cylinder on the scales; if the service cylinder is not equipped with a dip tube, invert the service cylinder, then place it on the scales. Open the high-side
valve on the gauge manifold.
7) Allow the system to charge with liquid until the proper charge weight is met.
8) Close the high-side valve on the gauge manifold. If charging is complete, skip to step 10.
9) If necessary, add any remaining charge to the system through the low-side.
NOTICE!To prevent compressor damage, use a throttling valve or liquid
dispensing device to add the remaining liquid charge through the low-side
refrigerant access valve with the compressor running. Close the refrigerant
cylinder valve and let the low-side refrigerant equalize to the system, then close the
low-side manifold gauge. Move the power switch to the "OFF" position (if applicable) or
unplug the appliance from the electrical outlet.
10) Pinch off (crimp down) the process tubes just below the piercing valves.
11) Remove the piercing valves. Cut the process tubes to remove the piercing valve holes
then braze the process tubes closed. Note: Be sure there is no refrigerant leak before
brazing.
12) Use a combustible gas leak detector or soap bubbles to check for leaks again.
13) Place red sleeves over the process tubes.
14) Plug the appliance back into the electrical outlet.
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B. Component Service Information
NOTICE
When replacing a component listed below, see the notes to help ensure proper
operation.
ComponentNotes
CompressorInstall a new start relay and compressor external protector. WARNING! To reduce the
risk of electric shock, be sure to reconnect the compressor's ground wire.
Thermostatic
Expansion Valve
• Attach the thermostatic expansion valve bulb to the suction line in the same location as
the previous bulb.
• The bulb should be between the 10 and 2 o'clock positions on the tube.
• Secure the bulb with the clamp and holder.
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V. Preparing the Appliance for Periods of Non-Use
When shutting down the appliance for periods of non-use, follow the instructions below.
WARNING
Prevent the doors from closing to reduce the risk of children getting trapped.
NOTICE
Clean the cabinet interior, door gaskets, and shelves.
1) Before shutting down the appliance, move the stored food into another refrigerator or
freezer.
2) Unplug the appliance. WARNING! To reduce the risk of electric shock, do not touch
the plug with damp hands.
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VI. Disposal
DANGER
Risk of Fire or Explosion Flammable Refrigerant Used
• Follow handling instructions carefully in compliance with U.S. government
regulations.
• Do not puncture refrigerant tubing. Risk of re or explosion due to puncture of
refrigerant tubing; follow handling instructions carefully.
• Dispose of properly in accordance with federal or local regulations.
Risque De Feu Ou D'Explosion Le Frigorigène Est Inammable
• Suivre attentivement les instructions de manipulation conformément à la
réglementation gouvernementale.
• Ne pas perforer la tubulure contenant le frigorigène. Risque de feu ou d'explosion
si la tubulure contenant le frigorigène est perforée; suivre les instructions de
manutention avec soin.
• Éliminer conformément aux règlements fédéraux ou locaux.
WARNING
When preparing the appliance for disposal, remove the doors/drawers to reduce the
risk of children getting trapped. Leave any shelves in place so that children may not
easily climb inside.
The appliance contains refrigerant and must be disposed of in accordance with
applicable national, state, and local codes and regulations. Refrigerant must be
recovered by properly certied service personnel.
See the nameplate for electrical and refrigeration specications. The nameplate is located
inside the cabinet.
We reserve the right to make changes in specications and design without prior notice.