Hoshizaki JWE-620UA-6B User Manual

NO. 80VC-782

ISSUED: OCT. 20, 2009

REVISED: MAR. 28, 2011

MODEL

HOSHIZAKI

DISHWASHER

JWE-620UA-6B

SERVICE MANUAL

IMPORTANT

Only qualifi ed service technicians should install, service, and maintain the
unit. No service or maintenance should be undertaken until the technician
has thoroughly read this Service Manual. Failure to service and maintain
the equipment in accordance with this manual may adversely affect safety,
performance, component life, and warranty coverage.

Hoshizaki provides this manual primarily to assist qualifi ed service technicians in the
maintenance and service of the unit.

Should the reader have any questions or concerns which have not been satisfactorily
addressed, please call, write, or send an e-mail message to the Hoshizaki Technical
Support Department for assistance.

HOSHIZAKI AMERICA, INC.
618 Highway 74 South
Peachtree City, GA 30269

Attn: Hoshizaki Technical Support Department
Phone: [phone] Technical Support

[phone]
Fax: [phone]
[phone]
E-mail: [e-mail]

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.

IMPORTANT

This manual should be read carefully before the unit is serviced or maintenance
operations are performed. Only qualifi ed service technicians should install,
service, and maintain the unit. Read the warnings contained in this booklet
carefully as they give important information regarding safety. Please retain this
booklet for any further reference that may be necessary.

CONTENTS

I. Specifi cations ------------------------------------------------------------------------------------------------ 1

A. Specifi cation Sheet ------------------------------------------------------------------------------------- 1
B. Nameplate Rating ---------------------------------------------------------------------------------------2
C. Dimensions/Connections ------------------------------------------------------------------------------ 3

II. General Information ---------------------------------------------------------------------------------------- 4

A. Construction ---------------------------------------------------------------------------------------------- 4

1. Dishwasher --------------------------------------------------------------------------------------------4

2. Internal Booster Tank -------------------------------------------------------------------------------5

3. Control Box --------------------------------------------------------------------------------------------6

B. Sequence of Operation -------------------------------------------------------------------------------- 8

1. Auto Fill Cycle ----------------------------------------------------------------------------------------- 8

2. Ready Cycle (Unit Inactive) ----------------------------------------------------------------------- 9

3. Wash Cycle -------------------------------------------------------------------------------------------- 9

4. Rinse Cycle -------------------------------------------------------------------------------------------10

5. Drain----------------------------------------------------------------------------------------------------11
C. Sequence of Operation Flow Chart ----------------------------------------------------------------12
D. Control Board and Operation Board ---------------------------------------------------------------14

1. Control Board Location ----------------------------------------------------------------------------14

2. Control Board Layout ------------------------------------------------------------------------------15

3. Control Board Diagram ----------------------------------------------------------------------------16

4. Operation Panel Layout ---------------------------------------------------------------------------18

5. Features -----------------------------------------------------------------------------------------------18

6. Controls, Adjustments, and Lamps -------------------------------------------------------------18

7. Service Menu and Error Log ---------------------------------------------------------------------19

8. Temperature Display -------------------------------------------------------------------------------22

9. Error Codes ------------------------------------------------------------------------------------------23

10. Buzzer -------------------------------------------------------------------------------------------------23

11. Special Modes ---------------------------------------------------------------------------------------23

III. Service Diagnosis ----------------------------------------------------------------------------------------26

A. Diagnostic Procedure ---------------------------------------------------------------------------------26
B. Error Codes ----------------------------------------------------------------------------------------------28

1. Error Code Table ------------------------------------------------------------------------------------28

2. Error Code Log --------------------------------------------------------------------------------------29

3. Error Code Details ----------------------------------------------------------------------------------30
C. Service Flow Charts -----------------------------------------------------------------------------------39

1. Unit Will Not Start -----------------------------------------------------------------------------------39

2. Dishes Not Clean -----------------------------------------------------------------------------------41

i

3. Inadequate Rinse -----------------------------------------------------------------------------------43

4. Dishwasher Will Not Start When Door Closed ----------------------------------------------44

5. No or Inadequate Detergent/Rinse Aid Supply ----------------------------------------------45

6. Wash Tank Water Boils ----------------------------------------------------------------------------45

7. Wash Tank Water Not Draining ------------------------------------------------------------------46
D. Float Switch Check and Cleaning ------------------------------------------------------------------47

1. Float Switch Check ---------------------------------------------------------------------------------47

2. Float Switch Cleaning ------------------------------------------------------------------------------47
E. Thermistor Check --------------------------------------------------------------------------------------48

IV. Removal and Replacement of Components -------------------------------------------------------49

A. Removal of Panels -------------------------------------------------------------------------------------49
B. Accessing the Control Box ---------------------------------------------------------------------------49
C. Removal and Replacement of Internal Booster Tank -----------------------------------------51
D. Removal and Replacement of Wash Pump Motor ---------------------------------------------52
E. Removal and Replacement of Rinse Pump Motor ---------------------------------------------53
F. Removal and Replacement of Handle -------------------------------------------------------------54
G. Removal and Replacement of Door ---------------------------------------------------------------55
H. Removal and Replacement of Spring Unit -------------------------------------------------------56
I. Removal and Replacement of Spring -------------------------------------------------------------56
J. Adjustment of Door Opening/Closing Force -----------------------------------------------------57
K. Removal and Replacement of Flush Pipe -------------------------------------------------------58
L. U-Packing Installation Instructions -----------------------------------------------------------------59
M. Removal and Replacement of Thermistor -------------------------------------------------------60
N. Removal and Replacement of Control Board or Operation Board -------------------------61

1. Control Board ----------------------------------------------------------------------------------------61

2. Operation Board -------------------------------------------------------------------------------------61

V. Cleaning and Maintenance Instructions -------------------------------------------------------------63

A. Daily Maintenance -------------------------------------------------------------------------------------63
B. Self-Cleaning --------------------------------------------------------------------------------------------65
C. Weekly Maintenance ----------------------------------------------------------------------------------66

1. Heater --------------------------------------------------------------------------------------------------66

2. Exterior ------------------------------------------------------------------------------------------------66

3. Wash Compartment --------------------------------------------------------------------------------66
D. Monthly Maintenance ---------------------------------------------------------------------------------66

1. Power Switch (Ground Fault Circuit Interrupter) --------------------------------------------66

2. Water Supply Line ----------------------------------------------------------------------------------66
E. Descaling (As Required) -----------------------------------------------------------------------------67
F. Shutdown -------------------------------------------------------------------------------------------------68
G. Long Storage, Relocation, Disposal, Transfer --------------------------------------------------69

VI. Operating Instructions -----------------------------------------------------------------------------------70
VII. Technical Information -----------------------------------------------------------------------------------71

A. Water Circuit ---------------------------------------------------------------------------------------------71
B. Wiring Diagram -----------------------------------------------------------------------------------------72

1. Auxiliary Code U-1, U-2, U-3, V-0, A-0 --------------------------------------------------------72

2. Auxiliary Code A-1 and Later ---------------------------------------------------------------------73

ii

Important Safety Information

Throughout this manual, notices appear to bring your attention to situations which could
result in death, serious injury, or damage to the unit.

WARNING

CAUTION

Indicates a situation which could result in damage to the unit.

IMPORTANT

This product 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.

To reduce the risk of death, electric shock, serious injury, or fi re, follow
basic precautions including the following:

• Only qualified service technicians should install, service, and maintain the
unit.

• Electrical connection must be hard-wired and must meet national, state, and
local electrical code requirements. Failure to meet these code requirements
could result in death, electric shock, serious injury, fi re, or severe damage to
equipment.

• This unit requires an independent power supply. See the nameplate for
proper voltage and breaker/fuse size. Failure to use a proper breaker or fuse
can result in a tripped breaker, blown fuse, or damage to existing wiring. This
could lead to heat generation or fi re.

• THIS UNIT MUST BE GROUNDED. Failure to properly ground this unit could
result in death or serious injury.

• Move the power switch (GFCI) to the “OFF” position, then turn off the power
supply before servicing. Lockout/Tagout to prevent the power supply from
being turned back on inadvertently.

• Do not make any alterations to the unit. Alterations could result in electric
shock, injury, fi re, or damage to the unit.

• To avoid possible burns and spills, be sure to drain the wash tank and internal
booster tank and let the components cool before servicing. When draining the
internal booster tank, wait until the water temperature falls below 104°F (40°C).

• When disassembling components that have been in contact with detergent,
wear rubber gloves and goggles. Before starting disassembly, thoroughly
read the detergent safety instructions. Contact with skin may cause irritation
and contact with eyes may cause blindness.

• When using an acidic descaling cleaner, wear rubber gloves and goggles.
Contact with skin may cause irritation, and contact with eyes may cause
blindness. Do not use or mix with a dishwashing detergent. Some detergents
may generate toxic chlorine gas.

Indicates a hazardous situation which could result in death or

serious injury.

Indicates important information about the use and care of the

unit.

WARNING

iii

I. Specifi cations
A. Specifi cation Sheet

WASH TANK SIDE BOOSTER TANK SIDE

AC SUPPLY VOLTAGE
POWER SUPPLY CAPACITY
AMPERAGE
STARTING AMPERAGE
ELECTRICAL CONSUMPTION

HEATER

RACK SIZE

NUMBER OF LARGE DISHES / RACK

CYCLE TIME
WATER CONSUMPTION
OUTSIDE DIMENSIONS
EXTERIOR
DOOR
WASH SYSTEM
RINSE SYSTEM
PUMP
DRAIN SYSTEM
START
DRY SYSTEM
REFUSE DISPOSAL
DETERGENT
DISPLAY

TANK CAPACITY
HOT WATER SUPPLY

TEMPERATURE CONTROL

CONNECTION – WATER SUPPLY
– DRAIN

WASH TIME Standard: 1 - 99 sec, in 1 sec steps

CONTROL

ELECTRIC CIRCUIT PROTECTION
BOIL – DRY PROTECTION

SAFETY SYSTEM

WEIGHT Net 247lb (112kg) / Gross 344lb (156kg)

PACKAGE

CERTIFICATION NSF ANSI-3, ETL, Energy Star

ACCESSORIES

OPERATION CONDITIONS

* The rated properties are based on measurements at ambient temperature of 86ºF (30ºC) according to the Technical

Requirements for Electrical Appliances.

* We reserve the right to make changes in specifications and design without prior to notice.

RINSE TIME
END BUZZER VOLUME

3 phase 3-wire 208-230V/60Hz (±10%)

15.8kVA(39.7A)
Max Running 36.6A, Rated Motor 4.2A

26.0A
Rated Motor 1.40kW (Power Factor 85%)
Max 14.30kW

6.9kW 6.0kW
19-3/4" × 19-3/4"(500 × 500mm)
16 plates (9.1” DIA)
53 sec (wash 41 sec, dwell 5 sec, rinse 6 sec, dwell 1 sec)

0.53Gal/cycle(2.0L/cycle)
W25.2" × D25.8" × H60.5" (W640 × D655 × H1,537mm)
Stainless Steel
Vertical Sliding Door (opening height 18.0") (457mm)
Upper and Lower Triple Spray Arms (common arms on top and bottom)
Upper and Lower Wide Angle Spray Arms
Wash 1HP, Rinse 0.134HP
Draw Out Overflow Pipe, Overflow Drain
Door Switch (start switch mode also available)
Residual Heat Drying
Filter Collection
Not Provided
Ready, Auto Fill, Rinse, Wash-Standard, Wash-Long, Pause
Wash Water Temperature, Rinse Water Temperature, Error

14.3Gal (54L)
Automatic Hot Water Supply by
Microprocessor Control
Wash: 150ºF(66ºC) min.

Thermistor Control: 163ºF(73ºF) ­168(76ºF)

Inlet: 3/4"FPT
Outlet: 1-1/2"MPT

Long: 10 - 990 sec, in 10 sec steps Microprocessor control
5 - 12 sec, Adjustable, in 1 sec steps
0 - Max, Adjustable
Ground Fault Circuit Interrupter (with Overcurrent Protector)
Water Level Switch,
Bimetal Thermostat (Manual - Reset),
Thermistor (Auto - Reset)
Door Switch, Emergency Stop by Microprocessor Control

Carton + Crate
W32.1"×D34.6"×H68.0" (815mm × 880mm × 1,726mm)

Universal rack (19-3/4" x 19-3/4") x 1, Instruction manual x 1
Installation manual x 1, Maintenance sheet (English and Spanish)x 1
Inlet water strainer & Packing x 1,
Ambient Temperature: 41 - 95ºF (5ºC - 35ºC)
Voltage Range: Rated Voltage ±10%
Recommends Water Hardness : 4gpg (grains per gallon) (68.5ppm) or less
Water Supply Temperature: 110 - 167ºF (43ºC - 75ºC) ( Recommends 140 ºF (60ºC))
Water Supply Pressure (Gauge Static Pressure): 10 - 70PSIG (0.07 - 0.48 MPa)

1.9Gal (7.3L)
Automatic Hot Water Supply by
Water Valve
Rinse: 180ºF(82ºC) min.

Thermistor Control: 182ºF(83ºC)-185ºF (85ºC)

Float Switch,
Bimetal Thermostat (Manual - Reset),
Thermistor (Auto - Reset)

1

B. Nameplate Rating

For certifi cation marks, see the nameplate on the dishwasher.

We reserve the right to make changes in specifi cations and design without prior notice.

2

C. Dimensions/Connections

Units: mm [in.]

3

II. General Information
A. Construction

1. Dishwasher

4

2. Internal Booster Tank

Legend: F/S–fl oat switch; H–heater; TH–thermistor

5

3. Control Box

a) Auxiliary Code U-1, U-2, U-3, V-0, A-0

Top Vi e w

Fan

Motor

Fan motor is attached to the base

Wash Tank Heater Control

Air Flow

Ground Fault Circuit Interrupter

Rinse PM Control

Side View

Wash PM Control

Internal Booster Tank Heater Control

Legend: CB–control board; GFCI–ground fault circuit interrupter; MC–magnetic contactor;

PM–pump motor; RX–phase reversal relay; TR–transformer; X–relay

6

b) Auxiliary Code A-1 and Later

Legend: CB–control board; GFCI–ground fault circuit interrupter; MC–magnetic contactor;

PM–pump motor; RX–phase reversal relay; TR–transformer; X–relay

7

B. Sequence of Operation

The steps in the sequence are as outlined below.

1. Auto Fill Cycle

a) Auxiliary Code U-1, U-2, U-3, V-0, A-0

“AUTO FILL” lamp fl ashing and “RINSE,” “STANDARD,” or “LONG” lamp on.

If WT WLS is open when power is supplied and the “ON/OFF” button is pressed, the “AUTO
FILL” lamp fl ashes and the auto fi ll cycle starts.
WV energizes. When BT WLF/S closes, WV de-energizes, RPM energizes and power is
supplied to RFT. RPM energizes and power is supplied to RFT for length of time set by
the rinse cycle time setting. For details, see “Rinse Cycle Time” (service menu item 03) in
“II.D.7.b) Service Menu Chart.” RPM then de-energizes for 10 seconds and power is cut
to RFT for 10 seconds. RPM energizes/de-energizes (and power is supplied to and cut to
RFT) the number of times set by the auto fi ll cycle setting. For details, see “Auto Fill Cycle”
(service menu item 07) in “II.D.7.b) Service Menu Chart.” During the auto fi ll cycle, BT
WLF/S opens/closes to energize/de-energize WV.
At the end of the auto fi ll cycle, there is a 5-second dwell time. CB checks WT WLS. If WT
WLS is closed, BZ beeps, the “AUTO FILL” lamp goes off and the “READY” lamp comes
on. If WT WLS is open, BZ beeps continuously, the “AUTO FILL” lamp goes off and “A1”
fl ashes in the display. For details, see “III.B.3.a) Auto Fill Error (A1).”

Note:

1. If DS opens during the auto fill cycle, the “AUTO FILL” lamp goes off, RPM de­energizes, and power is cut to RFT. When DS closes again, the “AUTO FILL” lamp
starts fl ashing and the unit resumes cycling RPM and power to RFT for the remaining
number of times determined by the auto fi ll cycle setting.

2. BTH and WTH are de-energized during the auto fi ll cycle.

3. If BT WLF/S fails, BT BUWLF/S assumes control. If BT BUWLF/S remains closed for 1
minute, o1 or o2 error appears in the display. For details, see “III.B. Error Codes.”

4. “STANDBY/CLEANING” button is inactive during the auto fi ll cycle.

b) Auxiliary Code A-1 and Later

"AUTO FILL" lamp fl ashing and "RINSE," "STANDARD," or "LONG" lamp on.

If WT WLS is open when power is supplied and the "ON/OFF" button is pressed, the
"AUTO FILL" lamp fl ashes and the auto fi ll cycle starts.
WV energizes. When BT WLF/S closes, WV de-energizes, and RPM energizes. RPM
energizes for length of time set by the rinse cycle time setting. For details, see "Rinse
Cycle Time" (service menu item 03) in "II.D.7.b) Service Menu Chart." RPM then de­energizes for 10 seconds. RPM energizes/de-energizes the number of times set by the
auto fi ll cycle setting. For details, see "Auto Fill Cycle" (service menu item 07) in "II.D.7.b)
Service Menu Chart." During the auto fi ll cycle, BT WLF/S opens/closes to energize/de-
energize WV.
At the end of the auto fi ll cycle, there is a 5-second dwell time. CB checks WT WLS. If WT
WLS is closed, BZ beeps, the "AUTO FILL" lamp goes off and the "READY" lamp comes

8

on. If WT WLS is open, BZ beeps continuously, the "AUTO FILL" lamp goes off and "A1"
fl ashes in the display. For details, see "III.B.3.a) Auto Fill Error (A1)."

Note:

1. If DS opens during the auto fi ll cycle, the "AUTO FILL" lamp goes off, and RPM de-
energizes. When DS closes again, the "AUTO FILL" lamp starts fl ashing and the unit
resumes cycling RPM for the remaining number of times determined by the auto fill
cycle setting.

2. BTH is de-energized during the auto fill cycle. WTH is energized if WT WLS closes
during the auto fi ll cycle.

3. If BT WLF/S fails, BT BUWLF/S assumes control. If BT BUWLF/S remains closed for 1
minute, o1 or o2 error appears in the display. For details, see "III.B. Error Codes."

4. "STANDBY/CLEANING" button is inactive during the auto fi ll cycle.

2. Ready Cycle (Unit Inactive)

"READY" lamp and "RINSE," "STANDARD," or "LONG" lamp on.

WT WLS closed. After a rinse cycle, RPM de-energizes and (except Auxiliary Code A-1
and later) power is cut to RFT.
WTH energizes when WT water temperature is at the wash temperature setpoint or
lower. For details, see "Wash Temperature Setpoint" (service menu item 04) in "II.D.7.b)
Service Menu Chart." WTH de-energizes when WT water temperature is 5°F (3°C) above
the setpoint. BTH energizes when BT water temperature is 3°F (2°C) below the rinse
temperature setpoint or lower. For details, see "Rinse Temperature Setpoint" (service
menu item 05) in "II.D.7.b) Service Menu Chart." BTH de-energizes when BT water
temperature reaches the setpoint. WV energizes/de-energizes when BT WLF/S opens/
closes.

Note: To prevent the wash or rinse cycle from starting when the door is closed (if service

menu item 11 is set for door start), press the "STANDBY/CLEANING" button. The
"READY" lamp goes off and the "STANDBY/CLEANING" lamp comes on. Press
the "STANDBY/CLEANING" button again to return to "READY." For details on start
initiation, see "Wash/Rinse Cycle Start Initiation" (service menu item 11) in "II.D.7.b)
Service Menu Chart."

3. Wash Cycle

The wash cycle can be started by either the door switch or the "STANDBY/CLEANING"
button. For details, see "Wash/Rinse Cycle Start Initiation" (service menu item 11) in "II.
D.7.b) Service Menu Chart."

Door Switch Start

When the "READY" lamp is on, the unit starts operation in the selected mode when DS
closes.

Note: If the "STANDBY/CLEANING" button is pressed when the "READY" lamp is on, the

"READY" lamp goes off and the "STANDBY" lamp comes on. When the "STANDBY"
lamp is on, the unit will not operate even if DS closes. To cancel standby, press the
"STANDBY/CLEANING" button.

9

"STANDBY/CLEANING" Button Start

When the "READY" lamp is on, the unit starts operation in the selected mode when the
"STANDBY/CLEANING" button is pressed.

"STANDARD" or "LONG" lamp fl ashing (depending on the wash mode selected).

WPM energizes and power is supplied to DFT for the length of time set by the wash cycle
time setting. For details, see "Wash Cycle Time (Standard Mode) or "Wash Cycle Time
(Long Mode)" (service menu item 01 or 02) in "II.D.7.b) Service Menu Chart."
WPM draws water from WT and sends it through the wash spray arms. When the wash
cycle time has expired, CB checks BT WLF/S. If BT WLF/S is open, the wash cycle is
extended and the lights in the display rotate. If BT WLF/S is closed, the unit enters a
5-second dwell time and then proceeds to the rinse cycle. If BT WLF/S does not close
within 10 minutes after the auto fi ll cycle starts, "A2" appears in the display, and the unit
shuts down. During the 5-second dwell time, detergent containing wash water on the door
liner and inside the wash spray arms fl ows back into WT.
During the wash cycle, WTH energizes when WT water temperature is at the wash
temperature setpoint or lower. For details, see "Wash Temperature Setpoint" (service
menu item 04) in "II.D.7.b) Service Menu Chart." WTH de-energizes when WT water
temperature is 5°F (3°C) above the setpoint. BTH energizes when BT water temperature
is 3°F (2°C) below the rinse temperature setpoint or lower. For details, see "Rinse
Temperature Setpoint" (service menu item 05) in "II.D.7.b) Service Menu Chart."
BTH de-energizes when BT water temperature reaches the setpoint. WV energizes/de­energizes when BT WLF/S opens/closes.

Note: If DS opens during the wash cycle, BZ beeps, the "STANDARD" or "LONG" lamp

goes off, the "READY" lamp comes on, WPM de-energizes and power is cut to
DFT. When DS closes again (if service menu item 11 is set for door start), the
"STANDARD" or "LONG" lamp starts fl ashing and the unit starts a new wash cycle.

4. Rinse Cycle

The rinse cycle starts automatically after the wash cycle. When the mode is set to "RINSE,"
the rinse cycle can also be started by either the door switch or the "STANDBY/CLEANING"
button. For details, see "Wash/Rinse Cycle Start Initiation" (service menu item 11) in "II.
D.7.b) Service Menu Chart."

Door Switch Start

When the "READY" lamp is on, the unit starts operation in the selected mode when DS
closes.

Note: If the "STANDBY/CLEANING" button is pressed when the "READY" lamp is on, the

"READY" lamp goes off and the "STANDBY" lamp comes on. When the "STANDBY"
lamp is on, the unit will not operate even if DS closes. To cancel standby, press the
"STANDBY/CLEANING" button.

"STANDBY/CLEANING" Button Start

When the "READY" lamp is on, the unit starts operation in the selected mode when the
"STANDBY/CLEANING" button is pressed.

10

"RINSE" lamp fl ashing.

RPM energizes and power is supplied to RFT for length of time set by the rinse cycle time
setting. For details, see "Rinse Cycle Time" (service menu item 03) in "II.D.7.b) Service
Menu Chart." RPM draws water from BT and sends it through the rinse spray arms. Rinse
aid is fed into the rinse water line and sprayed from the rinse spray arms together with
rinse water. Any excess water in WT drains through the overflow pipe. After RPM de­energizes, the unit enters a 1-second dwell time. After the dwell time, CB checks BT WLF/S.
If BT WLF/S is open, the lights in the display rotate until BT WLF/S closes. If BT WLF/S is
closed, BZ beeps for 2 seconds, the "READY" lamp comes on, and the unit returns to the
ready cycle. If BT WLF/S does not close within 10 minutes after the auto fi ll cycle starts,
"A2" appears in the display, and the unit shuts down. During the 1-second dwell time,
hot rinse water on the door liner and inside the rinse spray arms fl ows back into WT. The
"RINSE" lamp keeps fl ashing.
During the rinse cycle, WTH energizes when WT water temperature is at the wash
temperature setpoint or lower. For details, see "Wash Temperature Setpoint" (service
menu item 04) in "II.D.7.b) Service Menu Chart." WTH de-energizes when WT water
temperature is 5°F (3°C) above the setpoint. BTH energizes when BT water temperature
is 3°F (2°C) below the rinse temperature setpoint or lower. For details, see "Rinse
Temperature Setpoint" (service menu item 05) in "II.D.7.b) Service Menu Chart."
BTH de-energizes when BT water temperature reaches the setpoint. WV energizes/de­energizes when BT WLF/S opens/closes.

Note: If DS opens during the rinse cycle, BZ beeps, the "RINSE" lamp goes off, the

"READY" lamp comes on, RPM de-energizes, and power is cut to RFT. When DS
closes again (if service menu item 11 is set for door start), the unit starts a new
cycle in the selected mode.

5. Drain

This unit does not have a drain valve.
The overfl ow pipe in WT drains excess water from WT. To completely drain WT, remove
the overfl ow pipe.
To drain BT, fi rst move the power switch (GFCI) to the "OFF" position. Turn off the power
supply. Lockout/Tagout to prevent the power from being turned back on inadvertently.

Use BT drain hose to drain BT. WARNING! To avoid possible burns, allow BT water

temperature to fall below 104°F (40°C) before draining.

Legend: BT–internal booster tank; BTH–internal booster tank heater; BUWLF/S–backup

water level float switch; BZ–buzzer; CB–control board; DFT–detergent feeder
terminals (detergent feeder not provided by Hoshizaki); DS–door switch; RFT–
rinse aid feeder terminals (rinse aid feeder not provided by Hoshizaki); RPM–
rinse pump motor; WLF/S–water level float switch; WLS–water level sensor;
WPM–wash pump motor; WT–wash tank; WTH–wash tank heater; WV–inlet

water valve

11

C. Sequence of Operation Flow Chart

a) Auxiliary Code U-1, U-2, U-3, V-0, A-0

1-sec.

Dwell

Time

Starts after wash cycle. If mode is

set to "RINSE," can also be started

by door switch or "STANDBY/

CLEANING" button (service menu

item 11).

Rinse Cycle Time

(service menu

5-sec.

Dwell

item 03)

Time

4. Rinse Cycle

BT WLF/S check

Display lights

rotate if open

RPM energized (power supplied to RFT

when RPM energized)

RPM de-energized when unit enters

1-sec. dwell time (power cut to RFT when

RPM de-energized)

WTH energized when WT water temp. at

wash temp. setpoint (service menu item

04) or lower

WTH de-energized when WT water temp.

is 5°F (3°C) above wash temp. setpoint

(service menu item 04)

BTH energized when BT water temp. 3°F

(2°C) below rinse temp. setpoint (service

menu item 05) or lower

BTH de-energized when BT water temp.

reaches rinse temp. setpoint (service

menu item 05)

WV energized/de-energized by BT WLF/S

BTH de-energized when BT WLF/S

opens

WTH de-energized when WT WLS opens

BT WLF/S check

Cycle extended if open

(display lights rotate)

Cycle started by door switch or

"STANDBY/CLEANING" button

(service menu item 11).

Wash Cycle Time

(service menu

item 01 (Standard

Mode) or service

menu item 02

3. Wash Cycle

(Long Mode))

when WPM energized)

WPM energized (power supplied to DFT

JWE-620UA-6B

Dishwasher Sequence Flow Chart

2. Ready Cycle (Unit Inactive)

WT WLS closed

WTH energized when WT water temp.

at wash temp. setpoint (service menu

item 04) or lower

WTH de-energized when WT water

WT WLS

check.

WPM de-energized when unit enters

5-sec. dwell time (power cut to DFT when

WPM de-energized)

WTH energized when WT water temp. at

wash temp. setpoint (service menu item

04) or lower

WTH de-energized when WT water temp.

is 5°F (3°C) above wash temp. setpoint

(service menu item 04)

BTH energized when BT water temp. 3°F

(2°C) below rinse temp. setpoint (service

menu item 05) or lower

BTH de-energized when BT water temp.

reaches rinse temp. setpoint (service

temp. is 5°F (3°C) above wash temp.

setpoint (service menu item 04)

BTH energized when BT water temp.

3°F (2°C) below rinse temp. setpoint

(service menu item 05) or lower

BTH de-energized when BT water

temp. reaches rinse temp. setpoint

(service menu item 05)

WV energized/de-energized by

BT WLF/S

BTH de-energized when BT WLF/S

opens

WTH de-energized when WT WLS

opens

WT WLS open

menu item 05)

WV energized/de-energized by BT WLF/S

BTH de-energized when BT WLF/S

opens

WTH de-energized when WT WLS opens

de-energize. If DS opens during wash or rinse cycle, "READY" lamp comes on. When DS closes again (if service menu item

11 is set for door start), the mode lamp starts fl ashing. If in auto fi ll cycle, the unit resumes cycling RPM for the remaining

number of times determined by the auto fi ll cycle setting. If the unit was in a wash or rinse cycle, the unit starts a new cycle

in the selected mode.

Note: If DS opens during the auto fi ll, wash, or rinse cycle, BZ beeps, the corresponding cycle lamp goes off and RPM or WPM

start.

count: (service menu item 07).

• DS must be closed for cycle to

• RPM time: (service menu item 03).

1. Auto Fill Cycle

Cycle Steps

during Auto Fill Cycle.

• RPM energized/de-energized

• BTH and WTH are de-energized

Initial startup

WT WLS check.

Go to Ready

Cycle if closed.

begins here

WV energized/de-energized by

BT WLF/S

RPM energized (time=service menu

item 03)/de-energized (10 sec.)

(power supplied/cut to RFT as RPM

energized/de-energized)

12

"A1" error appears

in display.

Legend:

BT–internal booster tank

BTH–internal booster tank heater

BUWLF/S–backup water level fl oat switch

BZ–buzzer

CB–control board

DFT–detergent feeder terminals

DS–door switch

RFT–rinse aid feeder terminals

RPM–rinse pump motor

WLF/S–water level fl oat switch

WLS–water level sensor

WPM–wash pump motor

WT–wash tank

WTH–wash tank heater

WV–inlet water valve

b) Auxiliary Code A-1 and Later

1-sec.

Dwell

Time

Starts after wash cycle. If mode is

set to "RINSE," can also be started

by door switch or "STANDBY/

CLEANING" button (service menu

item 11).

Rinse Cycle Time

(service menu

5-sec.

Dwell

item 03)

Time

4. Rinse Cycle

BT WLF/S check

BT WLF/S check

Display lights

rotate if open

RPM de-energized)

RPM energized (power supplied to RFT

when RPM energized)

Cycle extended if open

(display lights rotate)

WTH energized when WT water temp. at

RPM de-energized when unit enters

1-sec. dwell time (power cut to RFT when

wash temp. setpoint (service menu item

04) or lower

WTH de-energized when WT water temp.

is 5°F (3°C) above wash temp. setpoint

(service menu item 04)

BTH energized when BT water temp. 3°F

(2°C) below rinse temp. setpoint (service

menu item 05) or lower

BTH de-energized when BT water temp.

reaches rinse temp. setpoint (service

menu item 05)

WV energized/de-energized by BT WLF/S

BTH de-energized when BT WLF/S

opens

WTH de-energized when WT WLS opens

Cycle started by door switch or

"STANDBY/CLEANING" button

(service menu item 11).

Wash Cycle Time

(service menu

item 01 (Standard

Mode) or service

menu item 02

3. Wash Cycle

(Long Mode))

when WPM energized)

WPM energized (power supplied to DFT

JWE-620UA-6B

Dishwasher Sequence Flow Chart

2. Ready Cycle (Unit Inactive)

start.

count: (service menu item 07).

• DS must be closed for cycle to

• RPM time: (service menu item 03).

1. Auto Fill Cycle

Fill Cycle.

• RPM energized/de-energized

• BTH is de-energized during Auto

• WTH energized when WT WLS

closed.

WT WLS closed

WTH energized when WT water temp.

is at wash temp. setpoint (service

menu item 04) or lower

WTH de-energized when WT water

WT WLS

check.

WT WLS check.

Go to Ready

Cycle if closed.

WV energized/de-energized by

BT WLF/S

RPM energized (time=service menu

WPM de-energized when unit enters

5-sec. dwell time (power cut to DFT when

WPM de-energized)

WTH energized when WT water temp. at

wash temp. setpoint (service menu item

04) or lower

WTH de-energized when WT water temp.

is 5°F (3°C) above wash temp. setpoint

(service menu item 04)

BTH energized when BT water temp. 3°F

(2°C) below rinse temp. setpoint (service

menu item 05) or lower

BTH de-energized when BT water temp.

reaches rinse temp. setpoint (service

temp. is 5°F (3°C) above wash temp.

setpoint (service menu item 04)

BTH energized when BT water temp.

3°F (2°C) below rinse temp. setpoint

(service menu item 05) or lower

BTH de-energized when BT water

temp. reaches rinse temp. setpoint

(service menu item 05)

WV energized/de-energized by

BT WLF/S

BTH de-energized when BT WLF/S

opens

WTH de-energized when WT WLS

opens

WT WLS open

item 03)

"A1" error appears

in display.

menu item 05)

WV energized/de-energized by BT WLF/S

BTH de-energized when BT WLF/S

opens

WTH de-energized when WT WLS opens

de-energize. If DS opens during wash or rinse cycle, "READY" lamp comes on. When DS closes again (if service menu item

11 is set for door start), the mode lamp starts fl ashing. If in auto fi ll cycle, the unit resumes cycling RPM for the remaining

number of times determined by the auto fi ll cycle setting. If the unit was in a wash or rinse cycle, the unit starts a new cycle

in the selected mode.

Note: If DS opens during the auto fi ll, wash, or rinse cycle, BZ beeps, the corresponding cycle lamp goes off and RPM or WPM

Cycle Steps

Initial startup

begins here

13

Legend:

BT–internal booster tank

BTH–internal booster tank heater

BUWLF/S–backup water level fl oat switch

BZ–buzzer

CB–control board

DFT–detergent feeder terminals

DS–door switch

RFT–rinse aid feeder terminals

WLS–water level sensor

WPM–wash pump motor

WT–wash tank

WTH–wash tank heater

RPM–rinse pump motor

WLF/S–water level fl oat switch

WV–inlet water valve

D. Control Board and Operation Board

• A Hoshizaki exclusive solid-state control board and operation board are employed in all

Hoshizaki dishwasher units.

• All models are pretested and factory set.

CAUTION

1. The control board and operation board are fragile; handle very carefully.

2. The control board and operation board contain integrated circuits, which
are susceptible to failure due to static discharge. It is especially important to
touch the metal part of the unit when handling or replacing the control board
or operation board.

3. Do not touch the electronic devices on the control board or operation board
or the back of the control board or operation board.

4. Do not attempt to repair the control board or operation board.

5. Do not short out power supply to test for voltage.

1. Control Board Location

The control box is located behind the front panel.
Follow the instructions and warnings for safe and
effi cient operation of the unit.

* The illustration shows relay

X13 provided only for Auxiliary
Code A-1 and later.

14

2. Control Board Layout

Inputs and outputs are laid out on the control board as illustrated below.

Signal Input XA Connector (10P)

Signal Input XA Connector (6P)

Thermistor Signal Input

XA Connector (4P)

4

1

8

1

5

1

1

CN7

CN6

CN5

CN8

10

1

CN11

3

CN9

Buzzer Volume

CN13

Buzzer Output XA Connector (2P)

Power Input VH Connector (4P)

2

16

CN10

High

Low

112

VR1

CN12

1 4

CN1

X1

X2

X3

X4

X5

X6

X7

13

CN2

1

6

1

7

CN3

1

5

CN4

Power Input VH Connector (6P)

Output VH Connector (7P)

Output VH Connector (5P)

Operation Board XA Connector (5P)

Heater Control Signal Input

XA Connector (8P)

XH Connector (3P): not in use

XH Connector (2P): not in use

XA Connector (3P): not in use

15

3. Control Board Diagram

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

1

a) Auxiliary Code U-1, U-2, U-3, V-0, A-0







200V from Transformer





Transformer

11V 7.7V



[Communication]
Operation Panel
Board

Shielded Wire

Wash Tank Thermistor

Internal Booster Tank Thermistor

Buzzer Output

JWE-620UA-6B

Pins 1-4 shorted: 3 phase control

Pins 1-4 open: Booster Tank control

1(CN1)41 (CN2)6

1
2
3
4
5

CN5

1
2

3
4

CN7

1

XA Connector

2
3

CN11

1

2

CN10

1

4

CN6

1

XH Connector

2
3

CN12

1

2

CN13

X1

X2

X3

X4

CN3

X5

X6

X7

CN4

2

5

XA Connector

6

CN9

1
2
3
4
5
6
7
8
9

10

CN8

1

3

5

7

1

[External

Relay]

MC3

MC1

X1

MC2

Door Switch

Internal Booster Tank Water Level Float Switch

Internal Booster Tank Backup Water Level Float Switch

Phase Reversal Input

Booster Tank Heater

Wash Tank Heater

Rinse Pump

Wash Pump

Water Valve

Wash Tank Electrode
(Water Level Sensor)

*1 Connectors CN 1 - 4 are VH Connectors

16

b) Auxiliary Code A-1 and Later

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

(

)

1







200V from Transformer





Transformer

11V 7.7V



[Communication]
Operation Panel
Board

Shielded Wire

Wash Tank Thermistor

Internal Booster Tank Thermistor

Buzzer Output

JWE-620UA-6B

Pins 1-4 shorted: 3 phase control

Pins 1-4 open: Booster Tank control

1(CN1)41 (CN2)6

1
2
3
4
5

CN5

1
2

3
4

CN7

1

XA Connector

2
3

CN11

1

2

CN10

1

4

CN6

1

XH Connector

2
3

CN12

1

2

CN13

X1

X2

X3

X4

CN3

X5

X6

X7

CN4

2

5

XA Connector

6

CN9

1
2
3
4
5
6
7
8
9

10

CN8

1

3

5

7

1

5

[External

Relay]

MC3

MC1

X10

MC2

X13

Door Switch

Internal Booster Tank Water Level Float Switch

Internal Booster Tank Backup Water Level Float Switch

Phase Reversal Input

Booster Tank Heater

Wash Tank Heater

Rinse Pump

Wash Pump

Water Valve

External Rinse Agent Feeder

Wash Tank Electrode
(Water Level Sensor)

*1 Connectors CN 1 - 4 are VH Connectors

17

4. Operation Panel Layout

The operation panel is mounted on the side of the unit and is connected to the CN5 connector
on the control board.

"READY" Lamp

"AUTO FILL" Lamp

Up Button

Down Button

Display

Mode Lamps

"STANDBY/
CLEANING" Lamp

"MODE" Button

"STANDBY/
CLEANING" Button

"ON/OFF" Button

5. Features

a) Display

This operation board uses an LED display to show system details and diagnostic
information.

b) Service Menu and Error Log

A service menu [“01” to “17” and “21” to “25” (Auxiliary Code U-1, U-2, U-3, V-0, A-0) or "01"
to "23" and "26" to "30" (Auxiliary Code A-1 and later)] allows for viewing and setting of system
operating details and parameters. See "II.D.7. Service Menu and Error Log."

c) Error Codes

Error codes ("A1" to "A3," "H1" to "H7," "o1," "o2") are designed to protect the unit. These codes
give information or warnings in the event the unit is operating out of acceptable parameters.
See "III.B. Error Codes."

6. Controls, Adjustments, and Lamps

a) "READY" Lamp

Comes on when the auto fi ll cycle completes and the dishwasher is ready to wash.

b) "AUTO FILL" Lamp

Flashes during the auto fi ll cycle, and goes off at the end of the cycle.

c) Mode Lamps

Comes on to indicate the selected operation mode, and fl ash during operation.

18

d) Standby Lamp

Comes on when the dishwasher is in the standby mode. The unit will not start even when the
door is closed with this lamp on. See "II.D.6.h) "STANDBY/CLEANING" button.

e) Up Button, Down Button

Press to scroll through the service menu and adjust settings. Can also be used as follows:
Press to display the total number of operations. Displays in six digits, two digits at a time.
Example: 123,456 times is indicated by
Press to indicate rinse (internal booster tank) water temperature instead of wash tank
water temperature while the dishwasher is in "READY" mode.

f) Display

Indicates wash tank water temperature in wash cycle, rinse (internal booster tank) water
temperature in rinse cycle, and error codes.

g) "MODE" Button

Press to change the selected operation mode.

h) "STANDBY/CLEANING" Button

Press to make the dishwasher inoperable even when the door is closed (service menu
item 11 set for door start) or press to start the selected mode (service menu item 11 set for
"STANDBY/CLEANING" button start). For details, see "Wash/Rinse Cycle Start Initiation"
(service menu item 11) in "II.D.7.b) Service Menu Chart." Press and hold to start self-cleaning
when the unit has been turned off using the "ON/OFF" button.

i) "ON/OFF" Button

Turns the power on and off for operation.
Note: The power switch (GFCI) supplies power to the unit. The unit, including heaters, is

inoperative until the "ON/OFF" button on the operation panel is pressed to turn the
unit on.

7. Service Menu and Error Log

The service menu [“01” to “17” and “21” to “25” (Auxiliary Code U-1, U-2, U-3, V-0, A-0) or
“01” to “23” and “26” to “30” (Auxiliary Code A-1 and later)] may be used to change settings,
acquire diagnostic information, and to view error history.

a) Service Menu Access

• Enter Service Menu: Use the "ON/OFF" button to turn off the unit. Press and hold the
"MODE" button, then press the "ON/OFF" button. "01" should appear on the display.

• Scroll: Use the up and down arrow buttons to scroll through the service menu list, settings,
and data.

• View Service Menu Setting: Press the "MODE" button to view the selected menu setting.

• Change Setting: Use the up and down arrow buttons to change the setting value.

• Return to Service Menu List: Press the "MODE" button once again to return to the main
service menu list.

• Exit Service Menu and Save Settings: Press the "STANDBY/CLEANING" button to exit the
service menu and save the settings. The display goes blank.

19