VOGT ICE 12A4171M12 Service Manual Download

Page: 58 / 100

6-8

MHG-RL Service Manual

ELECTRICAL CONTROLS

10/19/2009

Once the main menu appears, the system is ready to operate. The Main Menu has four
choices available: Settings, Control, Failures, and
Status.

•

Settings: The Settings Menu will present you
with two more choices, Ice Maker settings and
Screw Conveyor settings.

•

Control: The Control Menu will present you
with four choices, MCS Screen, Module
Modes, Conveyor Purge, and Module Pump Control.

•

Failures: The Failure Menu will present you with two choices, Present Failures,
and Failure History.

•

Status: The Status Menu will present you with three choices: Inputs, Outputs, and
Modules.

Note: a description is located in the next table for those items with ( )

Cycle Time (1)

Normal Defrost Time (2)

Dry Time (3)

Liquid Valve Control (4)

Hot Gas Main Valve Delay 5)

Manual Defrost Time (6)

Extended Defrost Time (7)

Cycle Extend Count (8)

Ice Maker

Water Pump Setting (9)

Settings

Screw Conveyor

Screw Run Time (15)

Master On/Off (20)

MCS Screen

Module Control (21)

Off (22)

Auto (23)

Manual Defrost, then Off (24)

Module Modes

Manual Defrost, then Auto (25)

Conveyor Purge

Purge (30)

Control

Module Pump Control

Manual Pump Control (32)

Silence (40)

Present Failure

Clear (41)

Failures

Failure History (42)

Inputs (43)

Outputs (44)

Main Menu

Status

Modules (45)

TABLE 6-6

Operator Interface Menu Map

Summary of Contents for 12A4171M12

Page 1: ...8 28 00 MHG LR MODULAR TURBO REFRIGERATING ICE MACHINE Manual Part Number 12A4171M12 Service Manual 5000 ...

Page 2: ...le additional expenses This manual is intended as an informational tool for the installation operation maintenance troubleshooting and servicing of this equipment If an existing situation calls for additional information not found herein we suggest that you contact your distributor first If further assistance or information is needed please feel free to contact the factory at 502 635 3000 or FAX a...

Page 3: ...ply ______ V _____ PH _____ Hz machine not running Compressor crankcase heater on 12 hour minimum All valves opened or closed as tagged Solenoid valve stems in auto position System leak checked tight Auxiliary equipment overloads wired into control circuit Water supply and drains connected properly Sufficient make up water supply minimum 30 PSIG Instruction manual and warranty certificate left on ...

Page 4: ......

Page 5: ...3 30 10 VOGT ICE LLC located in Louisville Kentucky since 1880 Sales 800 853 8648 Parts and Service 502 635 3000 Since 1880 Manufacturers of Quality Tube Ice Machines ...

Page 6: ...Vogt Turbo Refrigerating Ice Machines Installation Service Manual and Parts Catalog 12A4171M12 Modular Lowside Model ...

Page 7: ... 3 INSTALLING YOUR VOGT ICE MACHINE Machine Room 3 1 Lifting Procedures 3 1 Modular Unit Lifting Procedure FIGURE 3 1 3 2 Foundation Layout 3 2 Foundation Height Modular Unit FIGURE 3 2 3 3 Mounting Detail Modular Unit FIGURE 3 3 3 4 Piping and Drain Connections TABLE 3 1 3 4 Make up Water In 3 5 Water Tank Drain 3 5 Water Tank Overflow 3 5 Water Piping FIGURE 3 4 3 5 Wet Suction and Liquid Stop V...

Page 8: ...ide Layout FIGURE 4 3 4 4 5 START UP AND OPERATION Refrigeration System Review 5 1 Refrigerant Charge 5 2 Ammonia Specification By Grade Table 5 1 5 2 Special Precautions 5 2 Charging From Tank Truck dedicated high side only 5 2 Charging From Cylinders dedicated high side only 5 3 Start up Procedure 5 5 Thaw Gas Regulating and Suction By pass Valve Adjustment 5 5 Shut down Procedure 5 6 Operating ...

Page 9: ...tributors 7 4 Water Tank 7 4 Oil Trap Draining 7 5 Optional Maintenance Operations 7 5 Water Cooled Condenser Cleaning 7 5 Cooling Tower Evaporative Condenser 7 6 Cooling Tower Maintenance Schedule Table 7 3 7 6 Compressor Optional 7 7 Compressor Maintenance Table 7 4 7 7 8 TROUBLESHOOTING List Of Symptoms 8 1 Machine Stopped 8 2 Freeze up Due To Extended Freeze Period 8 3 Freeze Up Due To Ice Fai...

Page 10: ...r Float Valve 9 1 Refrigerant Float Switch 23 9 2 Hand Expansion Valve 9 9 2 Solenoid Valves 18 25 9 2 Control Circuit Fuse FU1 9 2 Circulating Water Pump 9 2 Pumpdown 9 2 Pumpdown Procedure 9 3 Removal of Ammonia Refrigerant 9 3 Refrigerant Leaks 9 4 Non condensable Gases 9 4 Purging Non condensable Gases 9 4 Purging Procedure 9 5 Draining the Oil Trap 9 5 Oil Trap Draining Procedure 9 5 Removing...

Page 11: ...ocess of making Tube Ice ice has been widely recognized as the most economical means of production The machine s economic and reliable operations have been proven over and over again in a network of varied types of installations throughout the world Furnished with your machine is the Certificate of Test the report of operating data that is a record of the unit s satisfactory operation on our facto...

Page 12: ...rant charging valve and cylinder valve before disconnecting the cylinder Loosen the union in the refrigerant charging line carefully to avoid unnecessary and illegal release of refrigerant into the atmosphere CAUTION Immediately close system charging valve at commencement of defrost or thawing cycle if refrigerant cylinder is connected Never leave a refrigerant cylinder connected to system except ...

Page 13: ...ual understand the operation of this machine and be aware of possible dangers These Safety Symbols will alert you when special care is needed Please heed DANGER Indicates an immediate hazard and that special precautions are necessary to avoid severe personal injury or death DANGER WARNING Indicates a strong possibility of a hazard and that an unsafe practice could result in severe personal injury ...

Page 14: ...MGH LR Service Manual INTRODUCTION 1 6 10 1 4 CONTROL PANEL EVAPORATOR PIPING WATER PIPING ACCESS DOOR WATER AND DRAIN CONNECTIONS FIGURE 1 1 Modular Flooded Front View ...

Page 15: ...MGH LR Service Manual INTRODUCTION 1 6 10 1 5 REFRIGERATION VALVE ACCESS ICE DISCHARGE FIGURE 1 2 Modular Flooded Back View ...

Page 16: ...MGH LR Service Manual INTRODUCTION 1 6 10 1 6 ICE DISCHARGE WATER PAN ACCESS FIGURE 1 3 Modular Flooded Right View ...

Page 17: ...n refrigerant liquid connection thaw gas connection make up water supply electrical connection and the proper refrigerant charge The machine has been partially factory tested prior to shipment and will require adjustment to meet the high side condenser unit operating conditions See Start up and Operation for the correct setting of the controls The machine is evacuated and charged with nitrogen gas...

Page 18: ...tions as specified in this manual You should be prepared to handle the ice produced as it is discharged from the machine and move it to your storage or bagging area promptly The machine nameplate is located on the front of the control panel The model number and machine description are located in the top left hand corner The following figure can be used to verify that the correct model has been rec...

Page 19: ...MGH LR Service Manual RECEIPT OF YOUR TURBO REFRIGERATING MACHINE 3 5 14 2 3 ...

Page 20: ...tion of the machine and should be avoided The electrical components of the Turbo Refrigerating machine are rated NEMA 1 The machine should not be located in a hazardous area or sprayed with water The machine should be installed in an area where water will not stand but will readily drain away from the machine See Space Diagram for clearances and utility connections FIGURE 3 1 Lifting Procedures CA...

Page 21: ...oundation should be constructed from concrete or similar material in accordance with all local and federal OSHA codes and building regulations The minimum required foundation size is shown in Figure 3 2 The foundations height will vary depending on the auxiliary equipment selected by the customer to transport ice to a bin or hopper Adequate space should be allowed for servicing operations such as ...

Page 22: ... Auger Size X 9 2 12 5 14 7 18 11 FIGURE 3 2 Foundation Height Modular Unit Figure 3 3 indicates minimum mounting requirements Contact your local distributor for seismic anchoring requirements in your area Additional bracing may need to be added to the top of the machine mounted to the lifting lug to meet local codes ...

Page 23: ... water pressure for satisfactory operation of the machine is 30 psig The maximum allowable pressure is 100 psig CAUTION Make up Water In Water Tank Drain Water Tank Overflow Water Tank Flush Valve Wet Suction Connection Liquid Connection Thaw Gas Connection 3 4 FPT 1 FPT 3 FPT 3 4 FPT 3 Flange 1 Flange 1 1 2 Flange The water tank drain connection must be extended to an open drain or sump arranged ...

Page 24: ...verflow line but no others Water Tank Overflow A 3 FPT connection on the rear of the machine is provided to carry away overflow water during the thawing harvest cycle This water contains ice fines accumulated during harvesting and dissolved solids accumulated during the freezing cycle Do not reduce the size of this line Three inches is needed to provide sufficient area for ice fines to be flushed ...

Page 25: ...ill be required A minimum compressor unloading during the harvest cycle is 66 If the compressor can not be unloaded then a hot gas bypass to the suction line must be installed Safety Valves This equipment is provided as a component of a larger refrigeration system As such pressure safety valves are not provided from the factory The end user bears the responsibility of the proper sizing selection i...

Page 26: ...MHG LR Service Manual INSTALLING YOUR ICE MACHINE 5 15 09 3 7 FIGURE 3 5 Spacing and Connection Diagram LR ...

Page 27: ...INE 9 29 14 3 8 NUMBER OF MODULES SUCTION LINE SIZE OD INCHES LIQUID LINE SIZE OD INCHES HOT GAS LINE SIZE OD INCHES MAKE UP WATER SUPPLY OD INCHES 1 3 1 1 4 2 3 4 2 4 1 1 2 2 1 3 5 2 2 1 1 4 4 5 2 3 1 1 2 5 6 2 1 2 4 2 6 8 2 1 2 4 2 FIGURE 3 6 Customer Piping LR ...

Page 28: ...MHG LR Service Manual INSTALLING YOUR ICE MACHINE 5 15 09 3 9 FIGURE 3 7 Piping Schematic LR ...

Page 29: ...MHG LR Service Manual INSTALLING YOUR TURBO REFRIGERATING MACHINE 9 29 14 3 10 ...

Page 30: ...ed near the Turbo Refrigerating machine Connect 3 phase power to terminals L1A L2A L3A in each Modular Panel for operation of the Turbo Refrigerating machine Connect 120 VAC control power to the Master Panel and each Modular unit as shown in the wiring diagrams A typical wiring example is shown below Rotation checking of the water pump is required see following section Also if one leg of the 3 pha...

Page 31: ...MHG LR Service Manual INSTALLING YOUR TURBO REFRIGERATING MACHINE 9 29 14 3 12 FIGURE 3 9 Master Panel Field Connections ...

Page 32: ...MHG LR Service Manual INSTALLING YOUR ICE MACHINE 5 15 09 3 13 FIGURE 3 10 Master Panel Field Connections Detail ...

Page 33: ...MHG LR Service Manual INSTALLING YOUR TURBO REFRIGERATING MACHINE 9 29 14 3 14 FIGURE 3 11 Master Panel Field Ethernet Connections Detail ...

Page 34: ...MHG LR Service Manual INSTALLING YOUR ICE MACHINE 5 15 09 3 15 FIGURE 3 12 Modular Panel Field Connections ...

Page 35: ...n should match the marking on the pump housing The pump will need to be primed by starting the machine in the clean mode and allowing it to run for several minutes To change direction of rotation for both cutter and pump disconnect power and reverse L1 and L3 incoming power wires at the compressor motor contactor Voltage Unbalance Voltage unbalance can cause motors to overheat and fail The maximum...

Page 36: ... and selection is the responsibility of the supplier of the components The tables are provided as guidelines only Standard helicoids screw conveyors with standard pitch single flight configurations are recommended for all applications With this design the pitch equals the diameter of the screw conveyor Although the maximum speed may vary from supplier to supplier 100 150 RPM is generally the maxim...

Page 37: ... 4 38 4 93 4 Percent Loading 90 Fragmented Ice TURBO TIG TIGAR Random non sized fragments Screw Conveyor Speed RPM Delivery Rate tons of ice per hour 9 Dia Screw 12 Dia Screw 16 Dia Screw Recommended 10 30 13 5 9 15 46 20 8 9 or 12 20 61 26 11 12 25 76 33 13 12 30 91 39 16 12 35 107 46 19 12 40 122 52 21 16 Ice density 36 pounds per cubic foot sized fragmented ice Shaded areas can be used Selectio...

Page 38: ...er supply and drain connections for conformity to requirements stipulated in this manual and properly connected to inlets and outlets CHECK ____ Electrical supply for proper size of fuses and for compliance to local and national codes See the machine nameplate for minimum circuit ampacity and maximum fuse size CHECK ____ All field installed equipment augers conveyors cooling towers bin level contr...

Page 39: ...MHG LR Service Manual INSTALLING YOUR TURBO REFRIGERATING MACHINE 9 29 14 3 20 ...

Page 40: ...tank The electrical circuit opens and closes the liquid line solenoid valve 2 the defrost solenoid valve 3 sometimes referred to as the D valve the wet suction solenoid valve 20 and the high pressure liquid feed valve 51 Refrigerant gas from the freezer 1 passes through the suction accumulator and to the compressor Here the cool gas is compressed to a high temperature high pressure gas which disch...

Page 41: ...through the ice slide it is discharged through the side opening The defrost time is to be set for the time required to discharge all the ice plus 20 seconds longer usually 60 seconds to 140 seconds depending on water pump operation CAUTION Make sure all the ice clears the freezer with at least 20 seconds to spare before the next freeze period begins This is to prevent refreezing CAUTION 1 Freezer ...

Page 42: ...MHG LR Service Manual HOW YOUR ICE MACHINE WORKS 1 6 2010 4 3 FIGURE 4 1 Piping Schematic ...

Page 43: ...MHG LR Service Manual HOW YOUR ICE MACHINE WORKS 1 6 2010 4 4 FIGURE 4 2 Water Piping Schematic LOW PRESSURE RECIEVER WET SUCTION LIQUID SUPPLY FIGURE 4 3 Typical High Side Layout ...

Page 44: ...ter tank of increased dissolved solids by flushing them out the overflow during the harvest thawing period The wet suction gas leaves the freezer and passes through the LPR where liquid droplets are removed and allowing dry gas to enter the suction side of the compressor The suction gas is then compressed and discharged once again completing the cycle As ice continues to form in the freezer plates...

Page 45: ...on systems should perform the operations described in this manual All local federal and EPA regulations must be strictly adhered to when handling ammonia R717 refrigerants See Material Safety Data Sheet MSDS Code5B81 83 for detailed information Charging From Tank Truck dedicated high side only The system may be charged by bulk from a tank truck and be pumped directly into the receiver through the ...

Page 46: ...e timer to maximum setting 8 Check compressor rotation by starting and stopping the compressor momentarily Jog the compressor by using the green Start push button PB2 and the red Stop push button PB1 in sequence Correct compressor rotation is indicated by an arrow on the outer rim of the oil pump assembly opposite the shaft end of the compressor 9 Set the water pump on one or modules to the Manual...

Page 47: ...nd open the tank drain valve somewhat to allow cold water to exit and warm water to enter continually The idea is to prevent ice from freezing on the plates as much as possible while charging It may be necessary to initiate a short harvest cycle to dispel any ice made To initiate a harvest cycle close the charging valve and press the mode switch on the Module 4 times within 3 seconds or use the op...

Page 48: ...n the freeze period 6 Observe the oil pressure the oil level the discharge pressure and listen for any unusual sounds The compressor should start unloaded and automatically load after several seconds of operation 7 Set the defrost gas pressure regulator See Defrost Gas Regulator on page 5 7 for instructions 8 Be sure to observe a minimum of four 4 cycles of ice production to confirm the satisfacto...

Page 49: ...al shutdown use the Master switch on the operator interface CAUTION 1 Set the Master switch on the operator interface to the Off position Do not use the machine disconnect to stop the machine If the disconnect is used the crankcase heater will be de energized and liquid refrigerant will migrate to the compressor 2 If in a freeze mode the machine will continue to run 3 At the completion of the free...

Page 50: ...t use the machine disconnect for normal shutdown of the machine Throw the Disconnect only in an emergency or for safety when performing certain service or repairs to the machine The compressor crankcase heater is de energized when the disconnect is thrown The Mode Switch push button at any Module can be used to initiate a harvest cycle by pressing it 3 times within 3 seconds When it is pushed duri...

Page 51: ...nce the timing of the ice harvesting in each module and also signal when to run the screw conveyor to convey ice away from the ice making Modules The Master Panel is also provided with a 3 operator interface that allows control of each ice making module various set points including refrigeration cycle time defrost time pump control screw conveyor runtime and many more Each Module s control panel i...

Page 52: ...s 24VDC for the ETH1 ETH1 Ethernet Switch used to connect the CAT5 wiring to each Modular ice maker CR1 Control Relay 1 used to signal the ammonia pump or compressor high when to run SFR Safety Failure Relay energized anytime the Master panel fails or detects a failure in one of the Modules HPLSR High Pressure Liquid Solenoid Relay this relay energizes any time the level switch in the surge detect...

Page 53: ... the various valves and relays wired to the panel and contains the program FUSE Fuse protects the control circuit inside the control panel LVR Liquid Valve Relay provides open and close control for motorized liquid valve SVR Suction Valve Relay provides open and close control for motorized suction valve PUMP Water Pump Motor Starter starts and provides overload protection for the water pump motor ...

Page 54: ...power to the control panels 2 Locate the ECOM card in your PLC and disconnect the Ethernet cable from the port on the front 3 Remove the ECOM card from the PLC by releasing the clips on top and bottom of the card and gently pulling the card out of the PLC 4 Locate the DIP switches as shown in the photo below 5 Using the table below set the DIP switches accordingly a Master Panel must have the ID s...

Page 55: ...lave 17 On Off Off On Off Off Off On 17 Module Slave 18 On Off Off On Off Off On Off 18 Module Slave 19 On Off Off On Off Off On On 19 Module Slave 20 On Off Off On Off On Off Off 20 TABLE 6 3 Dip switch settings for ECOM Modular Unit Operation In the first part of this chapter it was mentioned that the Modular unit control panel door has a pushbutton Mode Switch and an indicator light Mode Indica...

Page 56: ... Indicator will indicate which mode has been selected and will also indicate failures Failures will flash continuously until reset Following is a table to decode the various indicator flashes that may be seen Mode Indicator Flashes Description One Flash Module has shifted to the Off mode Two Flashes Module has shifted to the Auto mode Three Flashes Module has shifted to the Manual Defrost mode Onc...

Page 57: ...ode of each Module current status of each Module Factory presets can also be restored via the interface The operator interface has five function buttons and several screens for the input of set points and timer presets These screens are organized into groups See the tables figures below for a list of these groups and a description of what they control Previous Screen Control Home Failures Settings...

Page 58: ...e Status Menu will present you with three choices Inputs Outputs and Modules Note a description is located in the next table for those items with Cycle Time 1 Normal Defrost Time 2 Dry Time 3 Liquid Valve Control 4 Hot Gas Main Valve Delay 5 Manual Defrost Time 6 Extended Defrost Time 7 Cycle Extend Count 8 Ice Maker Water Pump Setting 9 Settings Screw Conveyor Screw Run Time 15 Master On Off 20 M...

Page 59: ...ntinues to run after defrost is complete Entered in seconds 20 Master On Off Controls the entire Modular Ice making System On will the system to run if conditions permit Off will stop the unit or prevent it from starting 21 Module Control Changes the screen to individual module control 22 Off Prevents the Module indicated from starting If the indicated module is already in an active ice making cyc...

Page 60: ...ut in the Auto mode via the pushbutton on the Modular unit or with the operator interface as shown by pressing the Auto button Once the desired modules are in the Auto mode go to the MCS screen and press the Master button The PLC will sequentially start each Module in a harvest cycle after which it will go into a freezing cycle The modules start sequentially in the order determined by the ID switc...

Page 61: ...eck calibration and operation of all controls high and low pressure switches oil pressure switch etc 2 Check cooling tower spray nozzles and pump suction screen for scaling and algae consult water treatment suppliers for corrective measures 3 Check water distribution and freezer plates for scale accumulation 4 Check water tank for solids to be removed 5 Check all motor drive units compressor pump ...

Page 62: ...t level in receiver Drained oil from oil trap Compressor crankcase heater working Compressor net oil pressure gage reading less suction Motor amps Compressor ________ Cutter ________ Pump ________ Suction psig end of freeze __________ Discharge psig end of freeze _____________ Suction psig end of thaw __________ Discharge psig end of thaw _____________ Compressor water out ____ F Tower fan cycles ...

Page 63: ...xt ice harvest period 3 Remove ice from storage area or cover ice discharge opening to prevent water from splashing out and contaminating stored ice 4 Shut off water supply and drain water tank by removing the over flow tube 14 Remove any loose sediment from tank 5 Return the overflow piping and fill water tank approximately 25 gallons with warm water 6 Add 72 ounces 8 ounces per 3 gallons of Calg...

Page 64: ... and scrubbing with a stiff brush After cleaning close drain and fill the water tank with fresh water When restarting the machine be sure that the water pump is circulating water It is possible that air may have collected in the pump impeller housing and the pump may have to be stopped and started several times to expel the air CAUTION The water distribution system is critical to proper machine op...

Page 65: ...cked and that water is flowing as required If the unit is controlled by a water treatment system the bleed off valve may not be required 2 Strainer The pan or sump strainer is located in the bottom of the sump at the suction connection to the pump The strainer should be inspected monthly and kept clean Do not operate the unit without the strainer in place 3 Make up water float valve This valve sho...

Page 66: ...Months Shutdown Clean debris from unit X X X Clean strainer and flush sump X X X Check fan and pump rotation X Clean spray nozzles X X Check belt tension X X Check for noise vibration X X Check adjust make up water valve X X Check adjust bleed rate X X Check lubricate fan bearings X X Lubricate motor base adj Screw X X X Drain sump and piping X TABLE 7 3 Cooling Tower Maintenance Schedule ...

Page 67: ...sure 35 50 psig Note Net oil pressure is calculated by subtracting the compressor suction pressure from the oil pressure gage reading while the compressor is running Example Oil pressure gage reading 65 psig Suction pressure gage reading 40 psig Net Oil Pressure 25 psig The compressor oil should be changed at close intervals during initial break in operation and up to the first 1000 hours see Tabl...

Page 68: ...to and pushing the MCS button on the Master Panel operator interface The machine will restart in a harvest to clear any ice from the freezer before beginning another cycle Always check the machine operation thoroughly after remedying the problem Be sure to correct the source or cause of the problem to prevent the problem from occurring again Symptom Page Machine stopped 8 2 Freeze up due to extend...

Page 69: ...ammed the conveyor Reset the overload and test by pushing the Purge push button on the operator interface Screw Purge screen Check voltage and amps against motor rating If tripping repeats but ice is not jammed check the conveyor for worn bearings liners and reducer motor for defect or single phasing Bin level control open The Bin Level Switch is installed in your ice storage bin and wires into th...

Page 70: ...nsufficient heat for defrost due to low condensing pressure The head pressure should be maintained form 175 190 psi maximum 200 usually by a water regulating valve or fan cycling switch Check to make sure these controls are working properly Cold prevailing wind can also be a factor Insufficient heat due to non condensables usually air in the system If non condensables are present with the refriger...

Page 71: ...rvest cycle Compressor running unloaded or not pumping full volume Check compressor motor amp draw Check for belt slippage and tighten as needed Check for leaking compressor suction or discharge valves Refer to your compressor manual See other related symptoms Restriction in the refrigerant liquid line or expansion device not operating properly Check for a partially closed valve or an obstruction ...

Page 72: ...ck sump strainer screen and clean Check condenser pump direction of rotation Fan control out of adjustment Check adjustment Replace if defective Non condensable in system If non condensables are present with the refrigerant the saturated temperature will not relate to the pressure reading at the receiver The refrigerant will be cooler although the pressure will be high Air can be purged from the s...

Page 73: ...re requirements Possible Cause Possible Remedy Oil diluted with refrigerant Oil will be very foamy Check liquid feed control for overfeed problem Oil pressure regulating valve out of adjustment Adjust valve to increase oil pressure Turn stem in to increase out to decrease Compressor rotation incorrect Check rotation direction by arrow indication Reverse rotation if necessary Restriction strainer o...

Page 74: ...r or replace as needed Internal relief valve leaking Check the compressor manual to see if your compressor is so equipped Replace accordingly Symptom Suction line frosting to compressor Possible Cause Possible Remedy Liquid refrigerant overfeed Check float switch to make sure it is functioning properly Replace if defective Check solenoid valve 25 to make sure it is not leaking through Repair or re...

Page 75: ...MHG LR Service Manual TROUBLESHOOTING 1 6 10 8 8 ...

Page 76: ...d Shut Off This setting controls the time period before defrost that closes the liquid solenoid This is used to improve harvest time Manual Defrost Time This setting controls the length of a user initiated manual defrost This setting is changed via the operator interface Manual Defrost can be initiated via the interface or the mode selection button on the Module Extended Defrost Time As an added f...

Page 77: ... the manual opening stem is in the closed or automatic position This means the stem is backed all the way out Correct direction of stem rotation should be labeled on the stem seal nut Control Circuit Fuse FU1 The electrical control circuit of the Master Panel and any Module Panel is protected by a fuse If fuse should open the machine will immediately stop Before replacing the fuse check power to t...

Page 78: ... the machine before opening the control panel cover With the pressure switch jumped out the machine can be manually started and stopped Do not operate the machine below 2 psig 6 When the desired pumpdown is obtained close the thawing gas stop valve and the compressor discharge line stop valve Other valves may also be closed to isolate a particular area that may require attention 7 To perform a tot...

Page 79: ...pected points of leakage A white cloud will form where a leak is even if it is very small Moisten a strip of test paper and pass it around the suspected area If the paper comes in contact with ammonia it will turn red Coils submerged in water or condenser cooling water may be tested by dipping a strip directly in the water If ammonia is present the paper will turn red Always remove refrigerant pre...

Page 80: ...to a minute size smaller than 1 16 it can be considered that most of the air has escaped and purging can be ceased at this point 7 Additional purging can be done at other purge points 8 When purging is completed close the valve disconnect the hose and install a plug in the purge valve Draining the Oil Trap After many hours of operation the oil which escapes the oil separator will pass through the ...

Page 81: ... Temperature Pressure chart for ammonia 3 With the freezer pressure below 25 PSIG attach a hose to the oil trap drain valve and extend the other end into a container 5 gallon bucket etc 4 Open the drain valve a little and drain out the oil and water that is present 5 Continue to drain oil water and purge the freezer and compressor to 0 PSIG 6 Close the compressor discharge stop valve and the oil r...

Page 82: ...ed for normal operation 13 When the receiver liquid level is near its normal operating level or the pressures are near equal and the compressor crankcase has warmed the compressor can be started and ice production resumed 14 After several cycles check the system for symptoms of excessive water and if necessary repeat the pumpdown and evacuation procedure Note whenever excessive water is present in...

Page 83: ...Appendix A ...

Page 84: ...dical aid SKIN CONTACT Immediately flush with large quantities of water for at least 15 minutes while removing clothing Clothing frozen to the skin should be thawed with water before removal Seek immediate medical aid INHALATION Remove from exposure If breathing has stopped or is difficult administer artificial respiration or oxygen as needed Seek immediate medical aid INGESTION Do not induce vomi...

Page 85: ... SECTION 12 ECOLOGICAL INFORMATION Aquatic Toxicity 2 0 2 5 ppm 1 4 days goldfish yellow perch LC 60 80 ppm 3 days crawfish LC100 8 2 ppm 96hr fatheadminnow TLm Waterfowl Toxicity 120 ppm Biochemical Oxygen Demand Not pertinent Food Chain Concentration Potential None SECTION 13 DISPOSAL CONSIDERATIONS Recover ammonia if feasible Otherwise let ammonia evaporate if appropriate Only personnel experie...

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