Service Manual Steelheart Series Refrigerated Kitchen Equipment Models Undercounter Worktop Prep Table hoshizakiamerica.
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 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.
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.
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.
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.
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 fingers when opening and closing the doors/drawers or rail cover (prep table models) or when handling food pans.
NOTICE WARNING, continued • 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. 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.
I. Construction and Refrigeration Circuit Diagram A. Construction 1.
B.
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. Model Default Cabinet Temperature Approximate Default Temperature Control Setting Undercounter Between 4 and 5 Refrigerator: 34°F (1°C) Worktop Freezer: -5°F (-21°C) Prep Table Between 4 and 5 34°F (1°C) A. Sequence of Operation Flow Chart 1.
EvapFM energized Legend: Comp-compressor ConFM-condenser fan motor CTh-cabinet thermistor DH-defrost heater DT-defrost timer DTh-defrost thermistor EvapFM-evaporator fan motor Power on Red LED On (5 sec. Delay) * 11 Delays * Defrost: Time/Temp achieved. 6-hr. DT terminates Evap. temp. below 50°F (10°C) DTh in control Evap. Temp. reaches 46°F (7.
Comp energized ConFM energized EvapFM energized MH energized PH energized Comp de-energized ConFM de-energized EvapFM de-energized MH de-energized PH de-energized CTh warms above setpoint 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 MH de-energized PH de-energized Defrost Terminated Defrost Termination: 50°F (°10C) achieved or 1 hr. backup defrost timer terminated. 5.
B. Service Diagnosis Risque De Feu Ou D'Explosion 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 fire or explosion due to puncture of refrigerant tubing; follow handling instructions carefully. • Component parts shall be replaced with like components.
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.
c) CM Diagnosis: Confirm green LED is flashing. 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. Confirm 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 flashing, replace CM. d) Comp/CondFM Diagnosis: Check that Comp and ConFM energize.
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. CTh cools below TD setting. TD setting satisfied. Comp, CondFM, and EvapFM de‑energize.
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: Confirm DH energizes (if applicable) and Comp, ConFM, and EvapFM (if applicable) de‑energize. If not, replace CM. (3) Comp and ConFM Diagnosis: Confirm Comp and ConFM de-energize. If not, check for 115VAC at CM 1 (C) (BR) to neutral (W).
C. Control Module Check 1. 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 flashing a green LED. This is normal operation.
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. Confirm 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. Confirm continuity of DTh. Replace as needed.
D. Diagnostic Table Before consulting the diagnostic tables, check the following: • Check the cabinet temperature control setting. See the table for default cabinet temperature control settings. Model Default Cabinet Temperature Approximate Default Temperature Control Setting Undercounter Between 4 and 5 Refrigerator: 34°F (1°C) Worktop Freezer: -5°F (-21°C) Prep Table Between 4 and 5 34°F (1°C) • Make sure the doors are not left open or opened too often and that they are sealing properly.
1. Appliance Not Cooling Appliance Not Cooling - Possible Cause 1. Power Supply a) Unplugged, blown fuse, or tripped or defective circuit breaker. 2. Power Supply Cord and Plug 3. Wiring 4. Cabinet Thermostat or Cabinet Thermistor 5. Cabinet Temperature Dial 6. Defrost Timer or Control Module (if applicable) 7. Evaporator Fan Motor 8. Condenser Fan Motor 9. Compressor External Protector 10. Compressor 11. Condenser 12. Evaporator 13. Refrigerant/Refrigerant Lines 10.
2. Evaporator is Frozen Up Evaporator is Frozen Up - Possible Cause 1. Evaporator a) Dirty. 2. Evaporator Fan Motor 3. Refrigerant Charge a) Defective. b) Fan blade binding. a) Low. 4. Defrost Heater (if applicable) a) Defective. 5. Defrost Timer or Control Module a) Defective. (if applicable) 6. Defrost Safety Thermostat Open (if applicable) 7. Thermostatic Expansion Valve (not adjustable) a) Defective. a) Defective. 3.
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 1 and the coldest setting is 7. See the table for default cabinet temperature control settings.
2. Prep Table and Freezer Temperature/Time-Initiated Defrost Cycle: Defrost cycle occurs once every 6 hrs. for prep tables or 8 hrs. for freezers when defrost initiation temperature achieved (50°F (10°C) for Prep Tables or 41°F (5°C) for the Freezers). Defrost cycle initiation and termination are controlled by the control module and defrost thermistor.
C. Safety Devices 1. Compressor External or Internal Protector (All Models) If combined temperature/amperage value is above the limit specified 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.
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 fire or explosion due to puncture of refrigerant tubing; follow handling instructions carefully. • Component parts shall be replaced with like components.
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 flammable refrigerant. • Do not work on appliance in a confined space. Confirm 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.
A. Refrigeration Circuit Service Information WARNING • Repairs requiring the refrigeration circuit to be opened must be performed by properly trained and EPA-certified 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.
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 Inflammable • L’entretien doit être effectué par le personnel de service autorisé par le fabricant afin de minimiser les risques d’inflammation attribuables à l’installation d’une pièce inadéquate ou à la mauvaise exécution du service.
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 flow backwards.
B. Component Service Information NOTICE When replacing a component listed below, see the notes to help ensure proper operation. Component Compressor Notes Install 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 • Attach the thermostatic expansion valve bulb to the suction line in the same location as Expansion Valve the previous bulb.
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.
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 fire or explosion due to puncture of refrigerant tubing; follow handling instructions carefully. • Dispose of properly in accordance with federal or local regulations.
VII. Technical Information A. Electrical and Refrigerant Data Model (includes drawer models) U/WR27A(-xxx) UR27A-GLP01 U/WF27A(-xx) UF27A-LP UF27A-GLP01 SR27A-(xxxxx) U/WR36A(-xx) SR36A(-xxx) U/WR48A(-01) U/WR48A-D2(-D4) UR48A-GLP01 U/WF48A(-xx) U/WF48A-D4 SR48A-(xxxxx) U/WR60A(-01) U/WR60A(-Dx) U/WF60A(-xx) SR60A-(xxxxx) U/WR72A(-01) U/WR72A(-D6) SR72A-(xxxxx) Design Pressure (PSIG) Refrigerant (oz.) AC Supply Voltage Amperes HIGH LOW R290 2.5 115/60/1 360 190 2.3 2.9 2.5 115/60/1 2.3 360 190 2.1 2.
B. Wiring Diagrams 1.
300±10 PSIG 190±20 PSIG Cut-Out Cut-In * High-Pressure Switch * ** 120°F±5°F (49°C±3°C) 70°F±5°F (21°C±3°C) Cut-Out Cut-In ** Defrost Thermostat 2.
360±30 PSIG 249±10 PSIG Cut-Out Cut-In * High-Pressure Switch 120°F±5°F (49°C±3°C) 70°F±5°F (21°C±3°C) Cut-Out Cut-In ** Defrost Thermostat * ** 3.
