Manitowoc RNS012 & RNS020 Nugget Ice Machines Technician’s Handbook This manual is updated as new information and models are released. Visit our website for the latest manual. www.manitowocice.
Safety Notices As you work on Manitowoc equipment, be sure to pay close attention to the safety notices in this handbook. Disregarding the notices may lead to serious injury and/or damage to the equipment. Throughout this handbook, you will see the following types of safety notices: ! Warning Text in a Warning box alerts you to a potential personal injury situation. Be sure to read the Warning statement before proceeding, and work carefully.
NOTE: Text set off as a Note provides you with simple, but useful, extra information about the procedure you are performing. Read These Before Proceeding: ! Caution Proper installation, care and maintenance are essential for maximum performance and troublefree operation of your Manitowoc equipment. Visit our website www.manitowocfsg.com for manual updates, translations, or contact information for service agents in your area.
! Warning Read this manual thoroughly before operating, installing or performing maintenance on the equipment. Failure to follow instructions in this manual can cause property damage, injury or death. ! Warning Do not use electrical appliances or accessories other than those supplied by Manitowoc for your ice machine model. ! Warning Two or more people or a lifting device are required to lift this appliance. ! Warning This equipment contains high voltage electricity and refrigerant charge.
! Warning Do not operate equipment that has been misused, abused, neglected, damaged, or altered/modified from that of original manufactured specifications. This 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 concerning use of the appliance by a person responsible for their safety. Do not allow children to play with this appliance.
! Warning It is the responsibility of the equipment owner to perform a Personal Protective Equipment Hazard Assessment to ensure adequate protection during maintenance procedures. ! Warning When using electric appliances, basic precautions must always be followed, including the following: a. Read all the instructions before using the appliance. b. To reduce the risk of injury, close supervision is necessary when an appliance is used near children. c. Do not contact moving parts. d.
Table of Contents General Information Model Numbers . . . . . . . . . . . . . . . . . . . . . 5 Model/Serial Number Location . . . . . . . . 5 Manitowoc Cleaner and Sanitizer . . . . 5 Ice Machine Warranty Information . . . 6 Commercial Warranty . . . . . . . . . . . . . . . 6 Residential Warranty . . . . . . . . . . . . . . . . 9 Installation Location of Ice Machine . . . . . . . . . . . . . . 13 Ice Machine Clearance Requirements . . 14 Ice Machine Heat of Rejection . . . . . . . . .
Maintenance Manitowoc’s Cleaning Technology . . . . 26 Exterior Cleaning . . . . . . . . . . . . . . . . 27 Preventative Maintenance Procedure . . 28 Heavily Scaled Cleaning Procedure . . . . 31 Cleaning And Sanitizing Procedure . . . . 33 Component Disassembly For Cleaning And Sanitizing . . . . . . . . . . . . . . . . . . . . . . . . . 36 General Information . . . . . . . . . . . . . . 36 Water Dump Valve . . . . . . . . . . . . . . . 50 Cleaning the Condenser . . . . . . . . . . .
Component Check Procedures Main Fuse . . . . . . . . . . . . . . . . . . . . . . 73 ICE/OFF/CLEAN Toggle Switch . . . . . 74 Float Switch . . . . . . . . . . . . . . . . . . . . . 75 Ice Damper and Hall Effect Switches . 76 Selector Switch . . . . . . . . . . . . . . . . . . 79 Dispense Lever Activated . . . . . . . . . . 79 Touchless Sensor Activated . . . . . . . . 80 Dispense Switch . . . . . . . . . . . . . . . . . 82 Touchless Sensor . . . . . . . . . . . . . . . . 83 High Pressure Cutout Control . . .
Component Specifications Main Fuse . . . . . . . . . . . . . . . . . . . . . . ICE/OFF/CLEAN Toggle Switch . . . . . High Pressure Cutout (HPCO) Control Filter-Driers . . . . . . . . . . . . . . . . . . . . . Total System Refrigerant Charge . . . . . . 103 103 103 103 104 Charts Cycle Times/24-Hour Ice Production/ Refrigerant Pressure Charts . . . . . . . . . . 105 RNS012A/RNS020A . . . . . . . . . . . . . . 106 Diagrams Wiring Diagrams . . . . . . . . . . . . . . . . . . .
General Information Model Numbers Self-Contained Air-Cooled RNS012A - Air-cooled lever dispense model RNS012AT - Air-cooled touchless dispense model RNS020A - Air-cooled lever dispense model RNS020AT - Air-cooled touchless dispense model Model/Serial Number Location These numbers are required when requesting information from your local Manitowoc Distributor, service representative, or Manitowoc Ice, Inc. The model and serial number are listed on the OWNER WARRANTY REGISTRATION CARD.
ICE MACHINE WARRANTY INFORMATION Owner Warranty Registration Card Warranty coverage begins the day the ice machine is installed. Important Complete and mail the OWNER WARRANTY REGISTRATION CARD as soon as possible to validate the installation date. If the OWNER WARRANTY REGISTRATION CARD is not returned, Manitowoc will use the date of sale to the Manitowoc Distributor as the first day of warranty coverage for your new ice machine.
Time and hourly rate schedules, as published from time to time by the COMPANY, apply to all service procedures. Additional expenses including without limitation, travel time, overtime premium, material cost, accessing or removal of the ice machine, or shipping are the responsibility of the owner, along with all maintenance, adjustments, cleaning, and ice purchases.
To secure prompt and continuing warranty service, the warranty registration card must be completed and sent to the COMPANY within five (5) days from the installation date. Complete the following and retain for your record: Distributor/Dealer Model Number Serial Number Installation Date MANITOWOC ICE 2110 So. 26th St., P.O. Box 1720, Manitowoc, WI 54220 Telephone: 920-682-0161 • Fax: 920-683-7585 Web Site - www.manitowocice.
Residential Warranty WHAT DOES THIS LIMITED WARRANTY COVER? Subject to the exclusions and limitations below, Manitowoc Ice (“Manitowoc”) warrants to the original consumer that any new ice machine manufactured by Manitowoc (the “Product”) shall be free of defects in material or workmanship for the warranty period outlined below under normal use and maintenance, and upon proper installation and start-up in accordance with the instruction manual supplied with the Product.
WHAT ARE MANITOWOC ICE’S OBLIGATIONS UNDER THIS LIMITED WARRANTY? If a defect arises and Manitowoc receives a valid warranty claim prior to the expiration of the warranty period, Manitowoc shall, at its option: (1) repair the Product at Manitowoc’s cost, including standard straight time labor charges, (2) replace the Product with one that is new or at least as functionally equivalent as the original, or (3) refund the purchase price for the Product.
WHAT IS NOT COVERED? This limited warranty does not cover, and you are solely responsible for the costs of: (1) periodic or routine maintenance, (2) repair or replacement of the Product or parts due to normal wear and tear, (3) defects or damage to the Product or parts resulting from misuse, abuse, neglect, or accidents, (4) defects or damage to the Product or parts resulting from improper or unauthorized alterations, modifications, or changes; and (5) defects or damage to any Product that has not been inst
IN NO EVENT SHALL MANITOWOC OR ANY OF ITS AFFILIATES BE LIABLE TO THE CONSUMER OR ANY OTHER PERSON FOR ANY INCIDENTAL, CONSEQUENTIAL OR SPECIAL DAMAGES OF ANY KIND (INCLUDING, WITHOUT LIMITATION, LOSS OF PROFITS, REVENUE OR BUSINESS) ARISING FROM OR IN ANY MANNER CONNECTED WITH THE PRODUCT, ANY BREACH OF THIS LIMITED WARRANTY, OR ANY OTHER CAUSE WHATSOEVER, WHETHER BASED ON CONTRACT, TORT OR ANY OTHER THEORY OF LIABILITY.
Installation ! Warning PERSONAL INJURY POTENTIAL Remove all ice machine panels before lifting and installing. Location of Ice Machine The location selected for the ice machine must meet the following criteria. If any of these criteria are not met, select another location. • The location must be indoors. • The location must be free of airborne and other contaminants. • The air temperature must be at least 45°F (7°C), but must not exceed 110°F (43°C).
Ice Machine Clearance Requirements RNS012 - RNS020 Self-Contained Air-Cooled Top 24" (61.0 cm) Sides 8" (20.3 cm) Back 5" (12.7 cm) RNS012 - RNS020 airflow is in the left side and out the top. Ice Machine Heat of Rejection Series Ice Machine Heat of Rejection* RNS012 - RNS020 2,300 Air Conditioning * BTU/Hour Because the heat of rejection varies during the ice making cycle, the figure shown is an average. Ice machines, like other refrigeration equipment, reject heat through the condenser.
Electrical Service General ! Warning All wiring must conform to local, state and national codes. Voltage The maximum allowable voltage variation is ± 10% of the rated voltage on the ice machine model/serial number plate at start-up (when the electrical load is highest). Fuse/Circuit Breaker A separate fuse/circuit breaker must be provided for each ice machine. Circuit breakers must be H.A.C.R. rated (does not apply in Canada).
Ice Machine Head Section Water Supply and Drains POTABLE WATER SUPPLY The ice machine must be connected to a potable water supply only. Local water conditions may require treatment of the water to inhibit scale formation, filter sediment, remove chlorine, and improve taste and clarity. Important If you are installing a Manitowoc water filter system, refer to the Installation Instructions supplied with the filter system for ice making water inlet connections.
DRAIN CONNECTIONS Follow these guidelines when installing drain lines to prevent drain water from flowing back into the ice machine and storage bin: • Drain lines must have a 1.5 in. (3.8 cm) drop per 5 ft. of run (2.5 cm per meter), and must not create traps. • The floor drain must be large enough to accommodate drainage from all drains. • Run separate bin and water-cooled condenser drain lines. Insulate them to prevent condensation. • Vent the bin drain to the atmosphere.
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Operation Ice Making Sequence of Operation RNS012 - RNS020 NUGGET MACHINES Ice Making Sequence of Operation PRIOR TO STARTUP When the toggle switch is placed in the ICE position the following must occur in the listed order before ice making will start. • The 15 minute delay period must be expired. The delay period starts upon application of power or a change in toggle switch position. • The ice chute damper must be in the closed or down position.
AUTOMATIC SHUTOFF When the ice damper is held open by ice, the gear motor, compressor and condenser fan de-energize. The five minute delay period starts to time out. The ice machine will remain off until the 15 minute delay period expires and the ice damper closes. RESTART AFTER AUTOMATIC SHUTOFF The 15 minute delay period must be expired. The delay period starts when the ice machine enters Automatic Shutoff and can not be overridden. 1. The ice machine was off for less than 30 minutes.
Control Board Features FLUSH CYCLE After the ice machine has completed 50 hours of run time a flush sequence will start. This cycle will drain and refill the evaporator to remove minerals that have settled to the bottom of the evaporator. The flush sequence lasts approximately 21 minutes, after which the ice machine will reset the 50 hour counter and automatically start ice making again. POWER INTERRUPTION DELAY If power is disconnected the ice machine stops.
22 SEQUENCE OF OPERATION CHART Nugget Machines Part Number STH044 10/13 Sequence Contactor Coil Dump Valve Gear Motor Ice Damper Duration Initial Start-Up The 15 minute delay must expire first Off Off On Closed Immediate Freeze Cycle On Off On Moves to Verify Ice Production Until Ice Holds Damper Open Automatic Shut-Off Off Off Off Open Until Damper Closes Restart More than 30 minutes have passed since automatic shutoff cycle initiated Off On On Closed 30 Seconds Restart Les
WATER LEVEL CHECK The float valve maintains the correct water level. The water level is factory set and normally will not require adjustment. The water level is correct if the Water Level indicator light is energized and no water is entering the overflow tube. The float valve is secured with 2 stop nuts. If an adjustment is required raise or lower the stop nuts as needed.
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Maintenance Maintenance procedures or failures due to a lack of maintenance are not covered by the warranty. Manitowoc Ice Machine Cleaner and Sanitizer are the only products approved for use in Manitowoc ice machines. ! Caution Use the correct Manitowoc approved metal safe Ice Machine Cleaner (part number 000000084) and Sanitizer (part number 94-0565-3). It is a violation of Federal law to use these solutions in a manner inconsistent with their labeling.
Manitowoc’s Cleaning Technology Manitowoc RNS012 - RNS020 Ice Machines allow the initiation and completion of a cleaning cycle at the flip of a switch. This cycle will permit cleaning of all surfaces that come in contact with the water distribution system. Periodic maintenance must be performed that includes sanitizing the bin and adjacent surface areas, which are not contacted by the water distribution system.
Preventative Maintenance Cleaning Procedure Perform this procedure as often as required for your water conditions: • Allows cleaning the ice machine without removing all of the ice from the bin/dispenser. • Removes mineral deposits from areas that are in direct contact with water during the Freeze cycle (reservoir, evaporator, auger, drain lines). EXTERIOR CLEANING Clean the area around the ice machine as often as necessary to maintain cleanliness and efficient operation.
Preventative Maintenance Procedure Ice machine cleaner is used to remove lime scale or other mineral deposits. It is not used to remove algae or slime. Refer to “Sanitizing Procedure” for removal of algae and slime. To initiate a cleaning cycle using Manitowoc’s Cleaning Technology use the following procedure. Step 1 To start a cleaning cycle, move the toggle switch to the CLEAN position. Water will flow through the water dump valve and down the drain. Step 2 Remove the cover from the top of the ice chute.
ADD SOLUTION HERE ICE WATER ICE / WATER Step 3 The ice machine will automatically time out a series of flush and rinse cycles, and then stops. This entire cycle lasts approximately 30 minutes. NOTE: Periodic cleaning must be performed on adjacent surface areas not contacted by the water distribution system. NOTE: The ice machine may be set to start and finish a cleaning procedure, and then automatically start ice making again. A. After cleaner is added move the switch from CLEAN to ICE position. B.
Changing toggle switch position during clean cycle: 1. Less than 60 seconds into Clean cycle - The Clean cycle will end when the toggle switch is moved to the OFF position. 2. More than 60 seconds into Clean cycle - The ice machine will complete the clean cycle. Toggle switch position will determine the next cycle after the Clean cycle is completed. • CLEAN POSITION - The ice machine will wait for a change in toggle switch position.
Heavily Scaled Cleaning Procedure Ice machines that are heavily scaled or have not been cleaned on a regular basis will need to run this Procedure. Failure to do so may result in binding of the auger as the lime scale releases from the auger and evaporator barrel. Step 1 Remove panels and set the ICE/OFF/CLEAN toggle switch to the OFF position. Step 2 Remove all ice from the bin. Step 3 Turn off the water supply to the ice machine. Step 4 Place ICE/OFF/CLEAN toggle switch in the CLEAN position.
ADD SOLUTION HERE ICE WATER ICE / WATER Step 1 Turn on the water supply to the ice machine. Important Leave the cleaner/water solution evaporator for a minimum of 4 hours. in the Step 2 Move the toggle switch to the ICE position. The compressor will energize and produce ice with the cleaning solution. Continue the freeze cycle for 15 minutes. Step 3 Move the toggle switch to the OFF position, then follow the standard cleaning and sanitizing procedures.
Cleaning And Sanitizing Procedure Ice machines that are heavily scaled or have not been cleaned on a regular basis will need to run the Heavily Scaled Cleaning Procedure before this one. Failure to do so may result in binding of the auger as the lime scale releases from the auger and evaporator barrel. Ice machine cleaner is used to remove lime scale or other mineral deposits. Ice machine sanitizer is used to remove algae or slime.
Step 6 Refer to chart and premix the correct solution of cleaner and cool water for your model ice machine. Model Amount of Cleaner Part Number 000000084 Amount of Water RNS012 RNS020 2 oz (60 ml) 32 oz (1 liter) Step 7 Remove the top cover from the ice chute and pour the cleaner/water solution into the evaporator. Add the entire amount of premixed solution (excess solution will exit through the overflow tube in the water reservoir).
Step 17 Remove the top cover from the ice chute and pour the sanitizer/water solution into the evaporator. Add the entire amount of premixed solution (excess solution will exit through the overflow tube in the water reservoir). Step 18 Replace the ice chute cover and allow the ice machine to stand for 30 minutes. Step 19 Turn on the water supply to the ice machine. Step 20 Move the toggle switch to the ICE position. The compressor will energize and produce ice with the sanitizing solution.
Component Disassembly For Cleaning And Sanitizing ! Warning Disconnect electric power to the ice machine at the electric switch box before proceeding. ! Warning Wear rubber gloves and safety goggles (and/or face shield) when handling Ice Machine Cleaner or Sanitizer. ! Caution Do not mix Cleaner and Sanitizer solutions together. It is a violation of Federal law to use these solutions in a manner inconsistent with their labeling. GENERAL INFORMATION 1.
Removal of Parts for Cleaning or Sanitizing 1. Turn off water supply to ice machine. 2. Place toggle switch in the clean position for 30 seconds to drain water from reservoir, then move toggle switch to Off position. 3. Run dispenser to transfer all ice from the bin to a container. ! Warning Disconnect electric power to the ice machine at the electric switch box before proceeding. 4. Disconnect electrical power to the ice machine. 5. Remove top cover. A. Remove two screws. B.
6. Remove front cover. A. Lift up on front cover. B. Pull forward to disengage keyhole slots. 7. Remove side panels.
8. Remove ice chute cover A. Turn the two thumbscrews 1/4 turn. B. Lift to remove cover.
9. Lift out ice damper.
10. Lift out ice strainer ramp.
11. Turn ice wiper counterclockwise to remove.
12. Loosen ice chute hose clamp. 13. Disconnect ice chute drain. 14. Lift up on ice chute to remove. The ice chute must be removed before the bin cover can be removed.
15. The ice chute can be cleaned in place. If complete removal is desired use a phillips screwdriver to remove the Hall Effect Switch assembly from the ice chute.
16. Remove three thumbscrews, then remove bin cover.
17. Remove agitator bar. • RNS012 - Remove the thumbscrew and lift off. • RNS020 - Unscrew the upright agitator bar. NOTE: Bar must be reassembled by inserting front edge into the paddle wheel, then lowering the back edge (rounded 90 angle) to prevent water leakage into the compressor compartment.
18. Remove ice deflector. A. Remove the two thumbscrews. B. Lift the ice deflector out.
19. Remove ice dispensing wheel by lifting straight out.
20. Water Reservoir Cover Removal A. Push up on cover to snap off.
WATER DUMP VALVE The water dump valve normally does not require removal for cleaning. To determine if removal is necessary: 1. Set the toggle switch to OFF. 2. Watch the water float valve. If the dump valve is leaking the float will continue to add water in the Off cycle. • If the dump valve is leaking, remove, disassemble and clean it. • If the dump valve is not leaking, do not remove it. Instead, follow the “Cleaning Procedure”. Follow the procedure below to remove the dump valve.
4. Remove the tubing from the dump valve by twisting the clamps off. 5. Remove the valve body from mounting bracket by twisting counterclockwise. .
CLEANING THE CONDENSER ! Warning Disconnect electric power to the ice machine at the electric service switch before cleaning the condenser. The condenser fins are sharp. Use care when cleaning them. A dirty condenser restricts airflow, resulting in excessively high operating temperatures. This reduces ice production and shortens component life. Clean the condenser at least every six months. Follow the steps below. 1.
Removal from Service/Winterization GENERAL Special precautions must be taken if the ice machine is to be removed from service for an extended period of time or exposed to ambient temperatures of 32°F (0°C) or below. ! Caution If water is allowed to remain in the ice machine in freezing temperatures, severe damage to some components could result. Damage of this nature is not covered by the warranty. 1. Disconnect the electric power at the circuit breaker or the electric service switch. 2.
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Troubleshooting SafeGuard Feature The ice machine will stop when conditions arise that would cause major component failure. Standby Mode The first time a failure occurs, the ice machine deenergizes and initiates a Standby Mode. The ice machine will remain off for 60 minutes, then automatically restart to see if the problem reoccurs. During the Standby Mode the corresponding light flashes continuously (disch temp, water level or speed).
Reset Procedure 1. Move the ICE/OFF/CLEAN toggle switch to OFF. A. If a safeguard feature has stopped the ice machine, it will restart after a short delay. Proceed to Step 2. B. If the ice machine does not restart, see “Ice Machine Does Not Operate.” 2. Allow the ice machine to run to determine if the condition is reoccurring. A. If the ice machine continues to run, the condition has corrected itself. Allow the ice machine to continue running. B.
SafeGuards • • No Water No Ice Production NO WATER The water sensing switch opens for more than 30 seconds. Operation When the float switch is open at initial start-up the ice machine will wait for the switch to close before starting. During the freeze cycle if the water float opens for 30 seconds the ice machine will: 1. De-energize the compressor and gearmotor. 2. The Water Ok light on the control board will deenergize. 3. A 15 minute delay is initiated.
NO ICE PRODUCTION The ice damper did not open and close at least once every 90 seconds in the freeze cycle. OPERATION During the first 8 minutes of operation: The control board must see the ice damper open/close at least once. This allows time for ice production to start at all ambient temperatures After the initial 8 minute period: The control board must see the ice damper open/close at least once every 90 seconds. When the ice damper does not open/close within the specified time the control board will: 1.
Reset Procedure Move the ICE/OFF/CLEAN toggle switch from OFF to ICE or disconnect and reapply power to the ice machine.
Ice Machine Will Not Run Diagnostics ! Warning High (line) voltage is applied to the control board (terminals #39 and #90) at all times. Removing control board fuse or moving the toggle switch to OFF will not remove the power supplied to the control board. The following sequence describes the normal start up procedure for the ice machine when line voltage is disconnected then reconnected to the ice machine. 1. Power is supplied to the control board. 2.
Part Number STH044 10/13 Ice Machine Will Not Run Power Supplied to Ice Machine? YES Reset Control Board, Disconnect And Reconnect Line Voltage YES NO Plug In Ice Machine, Reset Breaker IMPORTANT A Five Minute Delay Initiates After The Problem Is Corrected. This Delay Must Expire Before The Ice Machine Will Start.
62 YES Power At Terminals #90 & #39? NO Refer To High Pressure Cutout Specifications. IMPORTANT A Five Minute Delay Initiates After The Problem Is Corrected. This Delay Must Expire Before The Ice Machine Will Start. YES Part Number STH044 10/13 Nugget Control Board Light Energized? NO Disconnect HES #2 From Control Board.
Part Number STH044 10/13 YES Reservoir Full Of Water? NO Restore Water Supply NO Refer To Float Switch Diagnostics NO Install/Close Damper Door YES Float Switch Light On? YES Damper Door Closed? YES IMPORTANT A Five Minute Delay Initiates After The Problem Is Corrected. This Delay Must Expire Before The Ice Machine Will Start.
64 YES HES #1 Light Energized? NO Refer To Hall Effect Switch Diagnostics YES Hes # 2 Light Energized? NO Part Number STH044 10/13 YES Toggle Switch Functions? (If The Toggle Switch Energizes And De-Energizes The BLue Light, The Toggle Switch Is Ok) YES NO Refer to Toggle Switch Diagnostics IMPORTANT A Five Minute Delay Initiates After The Problem Is Corrected. This Delay Must Expire Before The Ice Machine Will Start.
Part Number STH044 10/13 YES 5 Minute Delay Expired? Wait For Delay To Expire, Then Refer To SafeGuards No YES Gearmotor Or Compresor Energizes? YES Refer to Compressor or Gearmotor Diagnostics No Refer to Control Board Fuse Diagnostics IMPORTANT A Five Minute Delay Initiates After The Problem Is Corrected. This Delay Must Expire Before The Ice Machine Will Start.
Refrigeration Diagnostics BEFORE BEGINNING SERVICE Ice machines may experience operational problems only during certain times of the day or night. A machine may function properly while it is being serviced, but malfunctions later. Information provided by the user can help the technician start in the right direction, and may be a determining factor in the final diagnosis.
WATER SYSTEM CHECKLIST A water-related problem could cause component misdiagnosis. Water system problems must be identified and eliminated prior to replacing other components. Possible Problem List Corrective Action List Water area (evaporator) is dirty. Clean as needed. Water inlet pressure not between 20 and 80 psig. Install a water regulator valve or increase the water pressure. Incoming water temperature is not between 45°F (1.7°C) and 90°F (32.2°C).
ICE PRODUCTION/QUALITY CHECK QUALITY CHECK Ice quality will vary with ambient and water temperatures, and is measured by the amount of excess water in the ice. An easy test is to squeeze a handful of ice. High quality ice releases only a small amount of water. As ice quality drops, more water can be removed. Generally speaking, higher incoming water temperature results in lower ice quality. Lower water temperature results in higher ice quality. ICE PRODUCTION CHECK 1.
ANALYZING DISCHARGE PRESSURE 1. Determine the ice machine operating conditions: • Air temperature entering condenser • Air temperature around ice machine • Water temperature entering water reservoir 2. Refer to 24-Hour Ice Production/Refrigeration Pressure Chart for ice machine being checked. Use the operating conditions determined in step 1 to find the published normal discharge pressures and compare to actual discharge pressure readings. 3. Measure the actual discharge pressure. 4.
Discharge Pressure Low Checklist Problem Cause Improper installation Refer to “Installation/Visual Inspection Checklist.” Improper refrigerant charge Undercharged Wrong type of refrigerant Other Low ambient temperature Non-Manitowoc components in system High side refrigerant lines/component restricted (before mid-condenser) Suction pressure is too low and affecting discharge pressure. (Refer to “Suction Pressure Low Checklist.
ANALYZING SUCTION PRESSURE NOTE: Analyze discharge pressure before analyzing suction pressure. High or low discharge pressure may be causing high or low suction pressure. Suction Pressure High Checklist Problem Cause Improper installation Refer to “Installation/Visual Inspection Checklist.” Discharge pressure Discharge pressure is too high and is affecting suction pressure. Refer to “Discharge Pressure High Checklist.
Suction Pressure Low Checklist Problem Cause Improper installation Refer to “Installation/Visual Inspection Checklist.” Discharge pressure Discharge pressure is too low and is affecting suction pressure. Refer to “Discharge Pressure Low Checklist.
Component Check Procedures MAIN FUSE FUNCTION The control board fuse stops ice machine operation if electrical components fail, causing high amp draw. SPECIFICATIONS The main fuse is 250 Volt, 10 amp, time delay. ! Warning High (line) voltage is applied to the control board at all times. Removing the control board fuse or moving the toggle switch to OFF will not remove the power supplied to the control board. CHECK PROCEDURE 1. Energized control board lights do not indicate a good fuse.
ICE/OFF/CLEAN TOGGLE SWITCH FUNCTION The switch is used to place the ice machine in ICE, OFF or CLEAN mode of operation. SPECIFICATIONS Single-pole, double-throw switch. The switch is connected into a varying low D.C. voltage circuit. CHECK PROCEDURE NOTE: Because of a wide variation in D.C. voltage, it is not recommended that a voltmeter be used to check toggle switch operation. 1. Inspect the toggle switch for correct wiring. 2. Isolate the toggle switch by disconnecting the Molex connector. 3.
FLOAT SWITCH FUNCTION The float switch prevents the ice machine from running when the water level is below the control setpoint. The float switch must be closed (float in up position) before the ice machine will start, and must remained closed throughout the freeze cycle. SPECIFICATIONS A mechanical liquid level sensor, that magnetically operates a reed switch. CHECK PROCEDURE NOTE: The water float switch is connected to the water reservoir cover.
ICE DAMPER AND HALL EFFECT SWITCHES Damper Door FUNCTION Opens and closes as ice passes from the ice chute to the bin. A metal lever attached to the damper interrupts the magnetic field sensed by the hall effect switches as the damper opens and closes. Hall Effect Switch #1 Operational Sensing This switch will open and re-close in conjunction with the ice damper as ice is discharged from the evaporator.
Hall Effect Switch Diagnostics All diagnostics must be performed with the ice damper installed and in the closed position. The control board lights will not indicate as described below with the ice damper in the open position. The ice damper must swing freely, if the damper is binding adjust/loosen screws that hold the Hall Effect Switch Housing in place. SWITCH FAILS OPEN OR IS DISCONNECTED HES#1 1. 2. 3. 4. Reset line voltage to the ice machine Wait 15 minutes for delay to expire.
SWITCH FAILS CLOSED HES#1 1. 2. 3. 4. Reset line voltage to the ice machine Wait 15 minutes for delay to expire. HES#1 light de-energized. The ice machine starts, runs for 20 seconds, then de-energizes. 5. HES#1 light is de-energized. HES#2 1. Reset line voltage to the ice machine 2. Wait 15 minutes for delay to expire. HES #2 is a three wire switch and can stop in three separate failure modes. • HES #1 is energized, HES #2 is de-energized, the ice machine will not start.
SELECTOR SWITCH FUNCTION Selects product dispensed. Ice, Water or Ice and Water. CHECK DISPENSE LEVER ACTIVATED Step 1 Verify line voltage is present at control board wires #20 & #22. Note - If a blue indicator light is energized on the touch pad the control board has line voltage. Step 2 Depress each selection on the touch pad.
TOUCHLESS SENSOR ACTIVATED Step 1 Verify line voltage is present at control board wires #20 & #22. Note - If a blue indicator light is energized on the touch pad the control board has line voltage. Step 2 Depress each selection on the touch pad.
Will Not Stop Dispensing • Disconnect sensor plug from sensor control board. • • If the dispensing stops, replace the sensor • If the dispensing continues disconnect wires #59 & #60 from the control board Check resistance across control board contacts • Closed = Replace the touchless sensing control board • Open = Dispense control board is not functioning correctly, check control board relays Replace the selector switch if ohm readings do not match all three switch settings.
DISPENSE SWITCH FUNCTION Supplies power to the product selector switch when activation lever is depressed. CHECK 1. Inspect the selector switch for correct wiring. 2. Isolate the switch by disconnecting all wires from the switch. 3. Check across the switch terminals with an ohm meter. Activation Lever Position Resistance Reading Depressed Closed Released Open Replace the selector switch if ohm readings do not match.
TOUCHLESS SENSOR FUNCTION Supplies power to the product selector switch when container activates sensor. CHECK Container must be within an inch of sensor to activate. Will Not Dispense 1. Verify power is supplied to the ice machine. When the toggle switch is in ICE position the blue LED light will be on. 2. Disconnect wires from C (common) and NO (normally open) terminals on the sensor control board. 3. Use an ohm meter to verify the switch is opening and closing.
HIGH PRESSURE CUTOUT CONTROL FUNCTION Stops the ice machine if subjected to excessive highside pressure. The HPCO control is normally closed, and opens on a rise in discharge pressure. Specifications Cut-Out Cut-In 450 psig ±10 (3103 kPa ±69) Automatic Reset 31 bar ±.69 (Must be below 300 psig (2068 kPa 20.68 bar) to reset.) CHECK PROCEDURE 1. Set ICE/OFF/CLEAN switch to OFF, (Manual reset HPCO reset if tripped). 2. Disconnect main power supply to the ice machine. 3.
FAN CYCLE CONTROL FUNCTION Energizes and de-energizes the condenser fan motor. The fan cycle control closes on an increase, and opens on a decrease in discharge pressure. Specifications Cut-In (Close) Cut-Out (Open) 250 psig ±5 200 psig ±5 CHECK PROCEDURE 1. Verify fan motor windings are not open or grounded, and fan spins freely. 2. Connect manifold gauge set to ice machine. 3. Hook voltmeter in parallel across the fan cycle control, leaving wires attached. 4. Refer to chart below.
LOW PRESSURE CUTOUT (LPCO) CONTROL FUNCTION Stops the ice machine if the low side pressure is too low. The LPCO control is closed at pressures above setpoint and opens at pressures below setpoint. Specifications Current Production & Replacement Part Cut-Out Cut-In 17 psig ±5 35 psig ±7 CHECK PROCEDURE 1. Connect manifold gauge set to suction access valve. 2. Disconnect wires from low pressure switch and connect ohm meter across LPCO terminals. Replace the LPCO control if it: 1.
COMPRESSOR ELECTRICAL DIAGNOSTICS The compressor does not start or will trip repeatedly on overload. Check Resistance (Ohm) Values NOTE: Compressor windings can have very low ohm values. Use a properly calibrated meter. Perform the resistance test after the compressor cools. The compressor dome should be cool enough to touch (below 120°F/49°C) to assure that the overload is closed and the resistance readings will be accurate. SINGLE PHASE COMPRESSORS 1.
Compressor Drawing Locked Rotor To determine if the compressor is seized, check the amp draw while the compressor is trying to start. The two likely causes of this are a defective starting component and a mechanically seized compressor. To determine which you have: 1. Install gauge on high and low side. 2. Try to start the compressor. 3. Watch the pressures closely. A. If the pressures do not move, the compressor is seized. Replace the compressor. B.
DIAGNOSING START COMPONENTS If the compressor attempts to start, or hums and trips the overload protector, check the start components before replacing the compressor. Capacitor Visual evidence of capacitor failure can include a bulged terminal end or a ruptured membrane. Do not assume a capacitor is good if no visual evidence is present. A good test is to install a known good substitute capacitor. Use a capacitor tester when checking a suspect capacitor.
Relay Operation Check ! Warning Disconnect electrical power to the ice machine before proceeding. • • • • 1. Disconnect wires from relay terminals. 2. Verify the contacts are closed. Measure the resistance between terminals 1 and 2. No continuity indicates open contacts. Replace the relay. 3. Check the relay coil. Measure the resistance between terminals 2 and 5. No resistance indicates an open coil. Replace the relay. 4. Move toggle switch to the ICE position. 5.
Refrigerant Recovery/Evacuation NORMAL SELF-CONTAINED PROCEDURES Do not purge refrigerant to the atmosphere. Capture refrigerant using recovery equipment. Follow the manufacturer’s recommendations. Important Manitowoc Ice assumes no responsibility for the use of contaminated refrigerant. Damage resulting from the use of contaminated refrigerant is the sole responsibility of the servicing company. Important Replace the liquid line drier before evacuating and recharging.
Recovery/Evacuation Procedures 1. Place the toggle switch in the OFF position. 2. Install manifold gauge set, scale, and recovery unit or two-stage vacuum pump. OPEN LOW SIDE ACCESS VALVE REFRIGERANT CYLINDER CLOSED OPEN HIGH SIDE ACCESS VALVE VACUUM PUMP/ RECOVERY UNIT OPEN SCALE RECOVERY/EVACUATION CONNECTIONS 3. Perform recovery or evacuation: A. Recovery: Operate the recovery unit as directed by the manufacturer’s instructions. B.
Charging Procedures Important The charge is critical on all Manitowoc ice machines. Use a scale to ensure the proper charge is installed. 1. Be sure the toggle switch is in the OFF position. MANIFOLD SET CLOSED OPEN LOW SIDE ACCESS VALVE HIGH SIDE ACCESS VALVE REFRIGERANT CYLINDER VACUUM PUMP/ RECOVERY UNIT OPEN SCALE CLOSED CHARGING CONNECTIONS SV3055 2. Close the vacuum pump valve and the low side manifold gauge valve. 3. Open the high side manifold gauge valve. 4.
7. Close the high side on the manifold gauge set. Add any remaining vapor charge through the suction access valve (if necessary). NOTE: Manifold gauge set must be removed properly to ensure that no refrigerant contamination or loss occurs. 8. Make sure that all of the vapor in the charging hoses is drawn into the ice machine before disconnecting the charging hoses. A. Run the ice machine in the Freeze cycle. B. Remove the quick disconnect fitting from the high side access valve at the ice machine. C.
System Contamination Clean-Up General This section describes the basic requirements for restoring contaminated systems to reliable service. Important Manitowoc Ice assumes no responsibility for the use of contaminated refrigerant. Damage resulting from the use of contaminated refrigerant is the sole responsibility of the servicing company. DETERMINING SEVERITY OF CONTAMINATION System contamination is generally caused by either moisture or residue from compressor burnout entering the refrigeration system.
Contamination Cleanup Chart Symptoms/Findings No symptoms or suspicion of contamination Moisture/Air Contamination symptoms Refrigeration system open to atmosphere for longer than 15 minutes Refrigeration test kit and/or acid oil test shows contamination Leak in water cooled condenser No burnout deposits in open compressor lines Mild Compressor Burnout symptoms Oil appears clean but smells acrid Refrigeration test kit or acid oil test shows harmful acid content No burnout deposits in open compressor lines S
CLEANUP PROCEDURE Mild System Contamination 1. Replace any failed components. 2. If the compressor is good, change the oil. 3. Replace the liquid line drier. NOTE: If the contamination is from moisture, use heat lamps during evacuation. Position them at the compressor, condenser and evaporator prior to evacuation. Do not position heat lamps too close to plastic components, or they may melt or warp. Important Dry nitrogen is recommended for this procedure. This will prevent refrigeration release. 4.
Severe System Contamination 1. Remove the refrigerant charge. 2. Remove the compressor. 3. Wipe away any burnout deposits from suction and discharge lines at compressor. 4. Sweep through the open system with dry nitrogen. Important Refrigerant sweeps are not recommended, as they release refrigerant into the atmosphere. 5. Install a new compressor and new start components. 6. Install a suction line filter-drier with acid and moisture removal capability.
Important Dry nitrogen is recommended for this procedure. This will prevent refrigerant release. 9. Follow the normal evacuation procedure, except replace the evacuation step with the following: A. Pull vacuum to 1000 microns. Break the vacuum with dry nitrogen and sweep the system. Pressurize to a minimum of 5 psig (35 kPa,.35 bar). B. Change the vacuum pump oil. C. Pull vacuum to 500 microns. Break the vacuum with dry nitrogen and sweep the system. Pressurize to a minimum of 5 psig (35 kPa,.35 bar). D.
REPLACING PRESSURE CONTROLS WITHOUT REMOVING REFRIGERANT CHARGE This procedure reduces repair time and cost. Use it when any of the following components require replacement, and the refrigeration system is operational and leak-free. • Fan cycle control • High pressure cut-out control • Low pressure control • High side service valve • Low side service valve Important This is a required in-warranty repair procedure. 1. Disconnect power to the ice machine. 2.
FIG. A – PINCHING OFF TUBING FIG.
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Component Specifications MAIN FUSE The main fuse is 250 Volt, 10 amp. ICE/OFF/CLEAN TOGGLE SWITCH Single-pole, double-throw switch. The switch is connected into a varying low D.C. voltage circuit. HIGH PRESSURE CUTOUT (HPCO) CONTROL Cut-Out Cut-In 450 psig ±10 (3103 kPa ±69) Automatic Reset 31 bar ±.69 (Must be below 300 psig (2068 kPa 20.68 bar) to reset.) FILTER-DRIERS Driers are covered as a warranty part. The drier must be replaced any time the system is opened for repairs.
Total System Refrigerant Charge Important This information is for reference only. Refer to the ice machine serial number tag to verify the system charge. Serial plate information overrides information listed on this page. Model Refrigerant Charge RNS012A/RNS020A 10 oz. / 284 g NOTE: All ice machines are charged using R-404A refrigerant.
Charts Cycle Times/24-Hour Ice Production/ Refrigerant Pressure Charts These charts are used as guidelines to verify correct ice machine operation. Accurate collection of data is essential to obtain the correct diagnosis. • Refer to “Refrigeration System Diagnostics” for the data that must be collected. This list includes: before beginning service, ice production check, installation/visual inspection, water system checklist, safeguards, discharge and suction pressure analysis.
RNS012A SELF-CONTAINED AIR-COOLED Characteristics will vary depending on operating conditions.
RNS020A SELF-CONTAINED AIR-COOLED Characteristics will vary depending on operating conditions.
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Diagrams Wiring Diagrams The following pages contain electrical wiring diagrams. Be sure you are referring to the correct diagram for the ice machine you are servicing. ! Warning Always disconnect power before working on electrical circuitry.
RNS012/RNS020 115/60/1 & 230/50/1 Refer to Nameplate for Voltage Rating TOUCH PAD MAIN FUSE HES1 (GRN) HES2 (GRN) CLEAN (YEL) WATER (GRN) TOGGLE SWITCH BLUE LED HES#1 B/K 65 HES#2 FLOAT SW.
Electronic Control Board RNS012 - RNS020 CONTROL BOARD AC LINE VOLTAGE ELECTRICAL PLUG MAIN FUSE HES1 (GRN) HES2 (GRN) CLEAN (YEL) WATER (GRN) TOGGLE SWITCH BLUE LED HES#1 B/K 65 HES#2 FLOAT SW.
Control Board Lights HES #1 - Green, works in conjunction with the Hall Effect Switch #1. When the ice damper is closed the light is on. HES #2 - Green, works in conjunction with the Hall Effect Switch #2. When the ice damper is closed the light is on. Clean - Yellow, indicates the unit is in a clean sequence. Water - Energizes when the water level in the reservoir closes (raises) the float switch. De-energizes when the float switch opens.
Refrigeration Tubing Schematic RNS012 - RNS020 EXPANSION VALVE EVAPORATOR HEAT EXCHANGER COMPRESSOR AIR CONDENSER DRIER Part Number STH044 10/13 113
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