Hoshizaki ROX-20TB2-U User Manual

Hoshizaki America, Inc.

Hoshizaki

Water Electrolyzer

Model

ROX-20TB2-U

“A Superior Degree

of Reliability”

www.hoshizaki.com

SERVICE MANUAL

Number: X002-858
Issued: 3-9-2012

IMPORTANT

Only qualified 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 qualified 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.

1

IMPORTANT

This manual should be read carefully before the unit is serviced or maintenance
operations are performed. Only qualified 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.

I. GENERAL INFORMATION --------------------------------------------------------------------------5

1. SAFETY INSTRUCTIONS -------------------------------------------------------------------------5

2. PRODUCT INFORMATION -----------------------------------------------------------------------7
[a] FEATURES ----------------------------------------------------------------------------------------7
[b] MODEL NAME -----------------------------------------------------------------------------------8

3. DIMENSIONS/SPECIFICATIONS ---------------------------------------------------------------9

4. PERFORMANCE DATA -------------------------------------------------------------------------- 10

II. TECHNICAL INFORMATION --------------------------------------------------------------------- 11

1. PRINCIPLE OF ELECTROLYSIS -------------------------------------------------------------- 11

2. CONSTRUCTION ---------------------------------------------------------------------------------- 14
[a] GENERAL --------------------------------------------------------------------------------------- 14
[b] MECHANISM ----------------------------------------------------------------------------------- 16
[c] CONTROL BOX -------------------------------------------------------------------------------- 17

3. WIRING DIAGRAM -------------------------------------------------------------------------------- 19

4. WATER CIRCUIT ---------------------------------------------------------------------------------- 20

5. FUNCTIONS AND OPERATION --------------------------------------------------------------- 21
[a] NORMAL MODE ------------------------------------------------------------------------------- 21
[b] SHORT MODE --------------------------------------------------------------------------------- 21
[c] ADJUSTMENT MODE ------------------------------------------------------------------------ 21
[d] CHECK MODE --------------------------------------------------------------------------------- 22

CONTENTS

PAGE

III. SERVICE INFORMATION ------------------------------------------------------------------------ 27

1. ERROR CODES ----------------------------------------------------------------------------------- 27

2. SERVICE DIAGNOSIS --------------------------------------------------------------------------- 27

3. FLOW RATE ADJUSTMENT -------------------------------------------------------------------- 29

4. REMOVAL AND REPLACEMENT OF COMPONENTS ---------------------------------- 30
[a] ELECTROLYTIC CELL ----------------------------------------------------------------------- 30

2

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

NOTICE

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

IMPORTANT

In the context of this manual, the term "sanitizing water" refers to acidic water and
"cleaning water" refers to alkaline water.

Indicates a hazardous situation which could result in death or

serious injury.

property.

Indicates important information about the use and care of the

unit.

WARNING

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 qualifi ed service technicians should install and service the unit.

• This unit must be installed in accordance with applicable national, state, and
local codes and regulations.

• 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 fuses, or damage to existing wiring.
This could lead to heat generation or fi re.

• THIS APPLIANCE MUST BE GROUNDED. This appliance is equipped

with a NEMA 5-15 three-prong grounding plug to reduce the risk of potential
shock hazards. It must be plugged into a properly grounded, independent
3-prong wall outlet. If the outlet is a 2-prong outlet, it is your personal
responsibility to have a qualified electrician 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 fi re.

• 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.

• This unit is not intended for outdoor use (including under canopy). Exposure
to rain may cause electric leak or shock. Direct sunlight can damage the
plastic tank exterior, resulting in cracks and water leaks.

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• Ensure adequate ventilation. Hydrogen gas or chlorine gas may cause
health problems.

• Do not mix electrolyzed water with other chemicals. Mixture with acidic
or chlorine-based chemicals can cause chlorine gas, resulting in health
problems.

• Do not use a large volume of sanitizing water only. Generation of a
large amount of chlorine gas may cause health problems or corrosion of
surrounding equipment.

• Do not use a flame near a container or tank holding electrolyzed water.
Hydrogen gas from cleaning water may cause ignition.

4

I. GENERAL INFORMATION

1. SAFETY INSTRUCTIONS

The following instructions contain important safety precautions and should be strictly
observed.

WARNING

1. When there is no need to energize the unit during disassembly or cleaning,
be sure to unplug the unit or disconnect the main power supply before
servicing the unit to prevent electric shocks.

2. If the unit must be energized for inspection of the electric circuit, use rubber
gloves to avoid contact with any live parts, which may result in electric
shocks.

3. Check for proper ground connections, and repair if necessary to prevent
electric shocks.

4. Always use service parts intended for the applicable model for replacement
of defective parts. Use proper tools to secure the wiring. Otherwise
abnormal operation or trouble may occur and cause electric leaks or fi re.

5. Check for proper part installations, wiring conditions and soldered or
solderless terminal connections to avoid smoke, fi re or electric shocks.

6. Be sure to replace damaged or deteriorated power cords and lead wires to
prevent electric shocks, fl ames or smoke.

7. Lead wires using solderless terminals or the like must be bound with their
closed ends up to avoid entrance of moisture that could lead to electric leaks
or fi re.

8. After servicing, always use a megohmmeter (500VDC) to check for
the insulation resistance of minimum 1 megohm between the live part
(attachment plug) and the dead metal part (ground terminal). Negligence in
checking may cause electric leaks or shocks.

9. Do not service the electrical parts with wet hands to prevent electric leaks or
shocks.

10. Always ask the user to keep children away from the work area. They may
be injured by tools or disassembled products.

5

NOTICE

1. After servicing, be sure to check for water leaks from the water supply and
drain lines to prevent wetting the surrounding properties.

2. After servicing, always check for proper operation.

CAUTION LABEL LOCATIONS

The following caution labels are attached where special care should be taken.

On top panel

Inside door

6

2. PRODUCT INFORMATION

[a] FEATURES

1) Space saving

The compact unit [W11" x D16" x H12" (W280 x D400 x H310 mm)] allows for

installation under sink.

2) Various optional parts available

Float switch: Detects the tank water level to automatically

start/stop operation. Includes the upper
and lower sanitizing water tank level float
switches and upper and lower cleaning
water tank level fl oat switches.

Outlet valve: Allows use of electrolyzed water stored in

the tank, as required. Connected with the
electrolyzed water outlets [for sanitizing
and cleaning water outlets] on the water
tank. Use as needed [yellow for sanitizing
water, blue for cleaning water].

3) Concentrated salt water direct injection system

Direct addition of concentrated salt water held in the salt water tank (accessory) into

the water fl ow requires no tank for diluted salt water, resulting in reducing the space
required.

4) Built-in current sensor

No salt concentration sensor is required. The built-in current sensor provides highly

accurate control.

5) Constant-voltage DC power supply

Current control by a constant-voltage power supply uses the salt concentration to

correct reduction of the electrolyzation effi ciency, resulting in stable concentration of
available chlorine.

6) Available chlorine concentration 20 - 30 mg/L or more

Sanitizing water contains undissociated hypochlorous acid (HOCl) which sanitizes

faster than sodium hypochlorite (NaOCl) and does not leave residue.

7) Built-in fl ow rate adjusting valve

The built-in fl ow rate adjusting valve automatically controls the fl ow rate according to

the selection (low, medium, high).

7

[b] MODEL NAME

ROX - 20 T B2 - U

For USA
Development order
Table-top or under-sink installation
Maximum fl ow rate (x 0.1 L/min)
Hoshizaki water electrolyzer

8

3. DIMENSIONS/SPECIFICATIONS

9