Hoshizaki ROX-20TA-U User manual

NO. U8AA-554
ISSUED: DEC. 29, 2000
REVISED:
SERVICE MANUAL
HOSHIZAKIHOSHIZAKI
HOSHIZAKIHOSHIZAKI
HOSHIZAKI
WATER ELECTROLYZERWATER ELECTROLYZER
WATER ELECTROLYZERWATER ELECTROLYZER
WATER ELECTROLYZER
MODEL ROX-20TA-UROX-20TA-U
ROX-20TA-UROX-20TA-U
ROX-20TA-U

U8AA5540012
CONTENTS PAGE
I.GENERALINFORMATION -------------------------------------------------------------------------- 1
1.SAFETYINSTRUCTIONS------------------------------------------------------------------------ 1
2.PRODUCTINFORMATION ---------------------------------------------------------------------- 3
[a] FEATURES ------------------------------------------------------------------------------------- 3
[b] MODEL NAME--------------------------------------------------------------------------------- 3
3.DIMENSIONS/CONNECTIONS----------------------------------------------------------------- 4
4. FEATURES OF STRONG ACID WATER----------------------------------------------------- 5
5. PRINCIPLE OF STRONG ACID WATER GENERATION --------------------------------- 6
II.CONSTRUCTION ------------------------------------------------------------------------------------- 7
1. GENERAL ------------------------------------------------------------------------------------------- 7
2. CONTROL PANEL -------------------------------------------------------------------------------- 9
3. DISPLAY PANEL----------------------------------------------------------------------------------10
4. CONTROL BOX----------------------------------------------------------------------------------- 11
5.REMOTECONTROLLER (OPTION) ---------------------------------------------------------12
6. WATER TANK FLOAT SWITCHES (OPTION)----------------------------------------------12
7. OUTLET VALVES (OPTION) -------------------------------------------------------------------12
III.OPERATINGINSTRUCTIONS --------------------------------------------------------------------13
1. FUNCTIONS AND ADJUSTMENT OF SET ITEMS---------------------------------------13
2. FUNCTIONS AND ADJUSTMENT OF CHECK ITEMS----------------------------------21
3. OPERATION FLOW CHART -------------------------------------------------------------------24
IV.TECHNICALINFORMATION ---------------------------------------------------------------------25
1.WATERCIRCUIT----------------------------------------------------------------------------------25
2.WIRINGDIAGRAM -------------------------------------------------------------------------------26
3. PERFORMANCE DATA-------------------------------------------------------------------------27
V. SERVICEINFORMATION -------------------------------------------------------------------------29
1.MAINTENANCE/INSPECTION ----------------------------------------------------------------29
2. SERVICE DIAGNOSIS --------------------------------------------------------------------------31

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U8AA5540012
I. GENERAL INFORMATION
1. SAFETY INSTRUCTIONS
Thefollowinginstructionscontainimportantsafetyprecautionsandshouldbestrictlyobserved.
The terms used here are defined as follows:
WARNING: There is a possibility of death or serious injury for the service person and a third
party or the user due to improper service operations or defects in serviced
products.
CAUTION: There is possibility of injury of the service person and a third party or the user or
damage to their property* due to improper service operations or defects in
serviced products.
* The term “damage to their property” here refers to extensive damage to houses, household
effects, livestock and pets.
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 earth 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 fire.
5. Check for proper part installations, wiring conditions and soldered or solderless terminal
connections to avoid smoke, fire or electric shocks.
6. Be sure to replace damaged or deteriorated power cords and lead wires to prevent electric
shocks, flames 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 fire.
8.Afterservicing, alwaysusea megohmmeter(DC500V)tocheckfortheinsulationresistance
of minimum 1 megohm between the live part (attachment plug) and the dead metal part
(earth 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.

2U8AA5540012
10. Always ask the user to keep children away from the work area. They may be injured by
tools or disassembled products.
CAUTION
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 LOCATION
The following caution labels are attached where special care should be taken.
On top panel
Inside door
On remote controller (option)
On bottom front of control box

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U8AA5540012
2. PRODUCT INFORMATION
[a] FEATURES
1) Space saving
The compact unit (W280 x D400 x H310 mm) allows for installation under sink.
2) Various optional parts available
RemoteController: Makes the dispensing section remotely operable at hand.
Float Switch: Detects thetank water levelto automaticallystart/stop operation.
OutletValve: Allows use of electrolyzed water stored in the tank, as required.
3) Concentrated salt water direct injection system
Direct addition of concentrated salt water held in the Salt Water Tank (accessory) into
the water flow 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
accuratecontrol.
5) Constant-voltage DC power supply
Currentcontrolby aconstant-voltagepower supplyusesthesaltconcentrationtocorrect
reduction of the electrolyzation efficiency, resulting in stable concentration of available
chlorine.
6) Available chlorine concentration 20 - 30 mg/L or more
Acid water contains undissociated hypochlorous acid (HOCl) which sanitizes faster
than sodium hypochlorite (NaOCl) and does not remain.
[b] MODEL NAME
ROX - 20 T A - U
For USA
Development Order
Table-top or under-sink installation
Maximum flow rate (x0.1L/min)
Hoshizaki Water Electrolyzer

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3. DIMENSIONS/CONNECTIONS Unit:inch(mm)

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U8AA5540012
4. FEATURES OF STRONG ACID WATER
Electrolyzedwater (electrolyzedfunctionalwater) isasolution withuseful functions causedby
electrolyzation of thin salt water or tap water. Different conditions of electrolyzation produce
various kinds of electrolyzed water whose applications are categorized into: [1] sanitation
(strong acid water, strong alkaline water, weak acid water, hypochlorous acid water) and [2]
consumption (alkaline ionized water). The Water Electrolyzer ROX-20TA-U produces strong
acid water and strong alkaline water in the category [1].
Strong acid water has the following features:
(1) Main Ingredient: Hypochlorous acid*1)
(2) pH: 2.2 - 2.7
(3) Oxidation-Reduction Potential*2): Max. +1100mV
(4) Available Chlorine Concentration*3): 20 - 60mg/L
(5) Color: None
(6)Others: Stimulative smell of chlorine
(containsun-electrolyzed salt)
*1) Hypochlorous acid (HOCl)
Dissolution of chlorine gas in water generates hypochlorous acid (HOCl) whose ratio to
hypochlorousacidion(ClO-)varies with the pH of water. InthepHrangeforstrongacid
water, much more HOCl than ClO-exists. Both HOCl and ClO-have a bactericidal
effect, but HOCl is much stronger than ClO-.
*2) Oxidation-Reduction Potential (ORP)
Oxidizing (or reducing) effect of the solution. The larger positive number indicates the
higher oxidizing effect.
*3) Available Chlorine Concentration
Chlorine concentration contributing to the bactericidal activity. It indicates the amount
of chlorine corresponding to iodine isolated in the following reaction:
NaOCl + 2Kl + 2CH3•COOH I2+ 2CH3•COOK + NaCl + H2O
Note: The terms related to chlorine are defined as below:
Residual Chlorine: Remaining chlorine as the result of excessive chlorine addition into
tap water to optimize the bactericidal effect of chlorination.
Free Chlorine: Chlorine (Cl2), hypochlorous acid (HOCl) and hypochlorous acid ion
(OCl-) generated by dissolution of chlorine in water.
Combined Chlorine: Chloramine (NH2Cl, NHCl2, NCl3) generated by dissolution of chlorine
in water containing ammoniate or organic nitride. Combined chlorine
isstableand durable, but notsoeffective inaquick bactericidal activity.
Available Chlorine: Combination of free chlorine and combined chlorine.

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5. PRINCIPLE OF STRONG ACID WATER GENERATION
Strong acid water is generated at the anode inside the Electrolytic Cell where the membrane
divides the anode and cathode, by electrolyzation of 0.1% or less salt water. See the figure
below.
At the anode, chlorine ion (Cl-) generates chlorine gas which reacts with H2O to generate
chloride and hypochlorous acid (HOCl). H2O is also electrolyzed at the anode to become
oxygen (O2) and hydrogen ion (H+). Eventually, the anolyte pH falls below 2.7, the oxidation-
reductionpotential(ORP) rises significantly,andthe available chlorine concentration reaches
20 - 60 mg/L.
[Reaction Formula]
Anode H2O 1/2O2+ H++ 2e-
2Cl-Cl2+ 2e-
Cl2(aq) + H2O HCl +HOCl
Cathode H2O + 2e-1/2H2+ OH-

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U8AA5540012
II. CONSTRUCTION
1. GENERAL
[1] Display Panel
See “3. DISPLAY PANEL“.
[2] Lamp Board
Board with lamps indicating unit status.
[3] Control Box
See “4. CONTROL BOX”.
[4] Flow Switching Valve
Changes the flow direction of electrolyzed water.
[5] Microswitch [Direction]
Senses the direction of the Flow Switching Valve.
[6] Microswitch [Location]
Senses the location of the Flow Switching Valve.
[7] Gear Motor
Rotates the Impeller inside the Flow Switching Valve.
[8] Water Valve
Supplies potable water to the Electrolytic Cell.
[9] Flow Rate Sensor
Senses potable water flow.
[10] Surge Absorber
Interrupts a temporary voltage surge.
[11] Electrolytic Cell
Electrolyzes diluted salt water and generates acid and alkaline water.
[12] Leg
Notadjustable.
[4]
[6] [5] [3]
[7] [2] [1]
[8]
[9] [15]
[10]
[11] [14]
[12] [13]
[17]
[16] [18]
[19]
[20]
[21]
[27]
[22]
[26]
[25] [24] [23]

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[13] Door
Provided with Door Lock.
[14] Door Lock
Locks the Door.
[15] Control Panel
See “2. CONTROL PANEL”.
[16] Acid Water Outlet
Dispensesacidwaterduringthenormaloperationandalkalinewaterduringtheflushing
process.
[17] Alkaline Water Outlet
Dispensesalkalinewaterduringthenormaloperationandacidwaterduringtheflushing
process.
[18]WaterSupplyInlet
Inlet for potable water supplied to the unit.
[19] Electromagnetic Metering Pump
Supplies salt water to the unit.
[20] Terminal Block
Used when the Water Tank (sold separately) is installed.
[21] Rear Panel (not shown)
Removed when the Water Tank Float Switches are connected to the Terminal Block or
the Remote Controller is connected to the Control Box.
[22] Blind Bushing
Removed when the Water Tank Float Switches are connected to the Terminal Block or
the Remote Controller is connected to the Control Box.
[23] Power Supply Cord
Flexible cord with a grounding conductor and grounding type attachment plug.
[24] Drain Cap
Used for draining the pipes.
[25] Salt Water Hose
Includes the PVC hose and the Water Level Sensor.
[26] Water Level Sensor
Senses the level of salt water inside the Salt Water Tank.
[27] Salt Water Filter
Removes foreign substances in salt water.