Twist TwistAero PCA090480WH Page 35 Maintenance Manual Download

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MODEL PCA090480WH

CHAPTER 3

TROUBLESHOOTING

Table of Contents

Table of Contents

March 2013

Page 64

Proprietary/Confidential

CHAPTER/

TITLE

SECTION

PAGE

Helpful Troubleshooting Information

Shortage of Refrigerant ............................................................ 3 - 5............... 85

Identifying a Refrigerant Leak................................................... 3 - 5............... 85

Air in the Refrigeration System................................................. 3 - 5............... 85

Clogged

Filter-Drier .................................................................. 3 - 5............... 86

Dirty

Condenser

Coil ................................................................ 3 - 5............... 86

Hot Gas By-pass Valve Obstructed.......................................... 3 - 5............... 86

Hot Gas By-pass Valve Adjustment Procedures ...................... 3 - 5............... 87

Expansion

Valve

Malfunction ................................................... 3 - 5............... 87

Charge

Lost ................................................................... 3 - 5............... 87

Valve Stuck in Open Position ........................................ 3 - 5............... 88

Valve Stuck in Closed Position ...................................... 3 - 5............... 88

Bulb

Miss-located .......................................................... 3 - 5............... 88

Moisture

Valve ........................................................... 3 - 5............... 88

Expansion Valve Field Disassembly/Re-assembly................... 3 - 5............... 89

Power

Element

Replacement ........................................ 3 - 5............... 90

Compressor Electrical Phase Rotation..................................... 3 - 5............... 90

Compressor Operating in a Vacuum ........................................ 3 - 5............... 91

Fusite

Failures ............................................................... 3 - 5............... 91

Scroll

Galling ................................................................. 3 - 5............... 91

Compressor

Motor

Megging ..................................................... 3 - 5............... 92

Overcharge of Refrigerant ........................................................ 3 - 5............... 92

Troubleshooting Direct Digital Controller (DDC)

Determine if ALC is Operating Property ................................... 3 - 6............... 93

Checking

Controller

Inputs ....................................................... 3 - 6............... 95

Checking

Controller

Output ...................................................... 3 - 6............... 95

Thermal

Overloads................................................................... 3 - 6............... 95

Control

Voltage......................................................................... 3 - 6............... 96

Smoke

Detector ....................................................................... 3 - 6............... 96

Phase

Monitor .......................................................................... 3 - 6............... 96

Heating

Coils ........................................................................... 3 - 6............... 96

Cooling

Compressors............................................................... 3 - 6 .............. 96

Property of American Airlines

Summary of Contents for TwistAero PCA090480WH

Page 1: ...P r o p e r t y o f A m e r i c a n A i r l i n e s Maintenance ...

Page 2: ... 35 Refrigerant Precautions 2 2 36 3 Refrigeration Basics and Service Theory 2 3 37 Basic Cycle Explanation 2 3 37 Fundamentals 2 3 38 Cleanliness of the Refrigeration System 2 3 38 Oil Refrigerant Mixture 2 3 39 Servicing System and Charging 2 3 40 Gauge Manifold 2 3 40 Service Valves 2 3 41 Removing Refrigerant 2 3 41 Adding or Removing Oil 2 3 42 Dealing with Non Condensable 2 3 43 Refrigerant ...

Page 3: ... 5 Preventive Maintenance Quarterly Checklist 2 5 51 6 Preventive Maintenance Semi Annual Checklist 2 6 53 7 Preventive Maintenance Seasonal Checklist 2 7 55 8 Adjustments Thermostats 2 8 57 Expansion Valve Superheat 2 8 57 Hot Gas By Pass Valve Adjustment 2 8 58 9 Cleaning and Painting Filters 2 9 59 Condensers 2 9 59 Evaporators and Ducts 2 9 59 Painting 2 9 60 P r o p e r t y o f A m e r i c a ...

Page 4: ...components of Twist Inc Pre Conditioned Air units must be accomplished in strict accordance with Twist Inc s specifications if performed by any party other than Twist Inc Any questions which owners may have relative to the installation maintenance or modification of Twist Inc s products should be referred to Twist Inc 2 Preventive Maintenance Rigidly adhering to a good program of preventive mainte...

Page 5: ...e no steps are overlooked 4 Maintenance or work done on the refrigeration systems must be done only by EPA certified personnel 4 Operator Daily Inspection A The PCA unit operator should visually check to ensure that no loose broken or missing components exist on the unit When connecting the supply air hose ensure that the gasket and clamps is in good physical condition B After confirming the overa...

Page 6: ... the refrigerant charge from both the high and low side of the compressor before removing the compressor from the system Whenever performing work on the unit turn off the external power and ensure that all OHSA and or company safety requirements are met NOTE The actuator handle mounted on the control panel door is equipped with provisions for inserting a lockout device when placed in the OFF posit...

Page 7: ...by itself is very stable however at high temperatures it may decompose to produce hydrochloric and hydrofluoric acid In the presence of open flame poisonous phosgene gas is produced WARNING DO NOT BRAZE PIPING WHICH HAS NOT BEEN PURGED OF REFRIGERANT THIS MAY RESULT IN AN EXPLOSION DUE TO THE OIL REFRIGERANT MIXTURE D Explosion Refrigerant by itself is not flammable however it is stored and shippe...

Page 8: ...s the pressure of the refrigerant to the evaporator by means of an orifice The reduction of pressure on the liquid refrigerant causes it to boil or vaporize until the refrigerant is at the saturation point corresponding to its pressure As the low temperature refrigerant passes through the evaporator coil heat from the air being conditioned flows through the walls of the evaporator tubing to the re...

Page 9: ...en joints to prevent moisture from entering in the form of vapor which is always contained in the outside air When copper tubing and fittings are brazed copper oxide may form on the inside of the tube unless nitrogen or dry CO2 is circulated through the tubing during the brazing operation This oxide may become a powdered abrasive plugging oil passages scoring bearings plugging refrigerant passages...

Page 10: ...ant and the compressor One of the basic characteristics of a refrigerant and oil mixture in a refrigeration system is the fact that refrigerant is attracted by oil and will vaporize and migrate through the system to the compressor crankcase even though no pressure difference exists to cause its movement Upon reaching the crankcase the refrigerant will condense into liquid and this migration will c...

Page 11: ...ht hand gauge is the high or discharge pressure gauge Flexible hoses are used to make connections from the manifold to the system Connecting the gauge manifold to a system is the most common service function To avoid introducing contaminants into the system always purge the hose connections with refrigerant The service person making the connections should always follow a consistent procedure Crack...

Page 12: ...ll service doors are closed as much as possible to allow proper airflow through the condenser coils C Removing Refrigerant Occasionally it will be necessary to remove the refrigerant from a system This may be required in order to repair leaks or make other repairs If a system has been overcharged it may be necessary to remove the excess charge to insure proper system operation EPA Regulations proh...

Page 13: ...r out with normal usage Excess oil can be removed from the compressors crankcase at the Oil Charging Valve which is located beneath the oil level of the compressor To remove oil connect a manifold hose to the Oil Charging Valve connection open the manifold valve slowly and allow the oil to run into a suitable container Take special care when removing the oil because of oil foaming The foaming not ...

Page 14: ...g system may result in the entrance of air Before purging non condensable gases from a system note the compressor operating discharge pressure and compare it with the temperature of the refrigerant see Appendix Since air is non condensable under the temperatures and pressures encountered in an air conditioning system the system s condensing pressure will increase due to the pressures exerted by th...

Page 15: ...S USE A GAUGE EQUIPPED PRESSURE REGULATOR ON THE HIGH PRESSURE BACK UP GAS AND NEVER INTERCONNECT THE REFRIGERANT CYLINDER AND THE INERT GAS CYLINDER THROUGH A GAUGE MANIFOLD NITROGEN AND CARBON DIOXIDE CYLINDER PRESSURES CAN RUPTURE A REFRIGERANT CYLINDER The electronic leak detector is the most sensitive type available and can detect small leaks of a fraction of an ounce per year often missed wh...

Page 16: ...ed on the test gauge will vary with atmospheric pressure reseal the system and leave it for at least 12 hours Any leakage of air into the system will cause the vacuum reading to decrease Changes in ambient temperature may cause some slight change in pressure If an air leak is indicated again pressure leak test the system and locate and repair the leaks G Brazing Refrigerant Lines The refrigeration...

Page 17: ...ved for inspection and pressure testing H Pressure Testing After repairs are made on a system refer to sub section F above to review pressure testing options Ensure that no leaks exist before proceeding forward If leaks are noted remove pressure from system and re solder joint s per sub section G I Evacuation Any time the compressor or system is exposed to atmospheric air or if the system becomes ...

Page 18: ... evacuating twice to 1500 microns and the last time to 500 microns When the procedure is complete the system is ready for charging J Charging With the gauge manifold connected to the service valves of the system connect the common hose to the refrigeration cylinder Loosen the common hose connection at the gauge manifold crack the refrigerant drum valve to purge the hose and retighten the hose conn...

Page 19: ...ubbles or flash gas even when the system is fully charged A restriction in the liquid line ahead of the sight glass may cause a sufficient pressure drop to cause flashing of the refrigerant If the expansion valve feed is erratic or surging the increased flow when the expansion valve is wide open can create a sufficient pressure drop to create flashing at the receiver outlet Rapid fluctuations in c...

Page 20: ...for the maintenance person to initial Twist Inc suggests those responsible for unit upkeep make copies of these checklists give them to the maintenance personnel and after the service work is completed bind these checklists into a history of the work performed The maintenance history must be accessible for review when filing warranty claims The checklists are numbered as follows 1 Quarterly 2 Semi...

Page 21: ...TER 2 SERVICE Section 4 Introduction to Preventive Maintenance Checklists 2 4 March 2013 Page 50 Proprietary Confidential 2013 Twist Inc This page left blank intentionally P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 22: ...the refrigerant sight glass A GREEN COLOR The system is dry and is normal B CHARTREUSE COLOR The system has some moisture and should be watched carefully Monthly checks should be initiated to look for additional change C YELLOW COLOR The system contains moisture and a qualified refrigeration serviceperson must change the drier since the system must be opened to braze in a new dryer and the entire ...

Page 23: ... repair if needed B Compressor cycling operating on and off more than every 3 minutes Repair if needed 11 Check supply hoses for holes tears abrasion wear or leaks Repair or replace as needed 12 Check all wire connections for tightness 13 Check fan hub to motor shaft for tightness Re torque hub set screws to motor shaft if necessary 14 Check general condition of fan blade assembly and replace if n...

Page 24: ...i Annual Checks in addition to the Quarterly Checks noted in Sections 5 DESCRIPTION DATE GOOD REPAIRED MECHANIC 1 Check all motors for free rotation and grease all zerk fittings with one half pump of the grease gun 1 2 Do not over lube 2 Inspect all components in main control panel and repair replace as necessary P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 25: ...HAPTER 2 SERVICE Section 6 Preventive Maintenance Semi Annual Checklist 2 6 March 2013 Page 54 Proprietary Confidential 2013 Twist Inc This page left blank intentionally P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 26: ...ns 5 and 6 COOLING SEASON CHECKS DATE GOOD REPAIRED MECHANIC 1 Verify that the oil level in the compressors are visible in the sight glass 2 Confirm refrigeration charge levels in all systems 3 Clean condenser coil Wash with mild soapy water Clean more often if environmental conditions dictates 4 Clean evaporator coil with mild soapy water Clean more often if environmental conditions dictates P r ...

Page 27: ...HAPTER 2 SERVICE Section 7 Preventative Maintenance Seasonal Checklist 2 7 March 2013 Page 56 Proprietary Confidential 2013 Twist Inc This page left blank intentionally P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 28: ...tem clockwise the number of turns recorded above This process will set the new valve to factory specifications When the adjustment is completed on the valve always tighten the adjusting stem packing nut and replace the seal cap tightly To determine superheat of the system A Measure the temperature of the suction line at the point the bulb is clamped B Read the gauge pressure at the suction valve n...

Page 29: ...upler B Start the unit and after the unit has run for 20 minutes restrict the outlet area of the aircraft coupling C All compressor systems should be operating D To adjust system one connect the low pressure gauge of a service manifold to the Schrader valve on the suction line and read the pressure Restrict the air flow until the gauge reads 130 psig E Feel the hot gas line downstream of the hot g...

Page 30: ...IOUS PERSONAL INJURY CAN RESULT WITH MISDIRECTED PRESSURIZED AIR 3 Evaporators and Ducts Clean the evaporator coil plenums air passages and ducts using a non acid alkaline based coil cleaner such as Nu brite Coil Cleaner Mix the solution with water as directed by the manufacturer There are access panels on the plenum to clean the evaporator coil The other way is to clean it by blowing the solution...

Page 31: ...ce review product data sheets and instructions that have been placed on the paint containers covering product warnings and precautions mixing application and curing of all the products specified for use Verify that all necessary materials are at the job site in acceptable condition and in the correct amounts Twist Inc recommends that the same materials used for factory painting be used in field ap...

Page 32: ...riming must be done immediately following the exposure of bare metal in order to prevent additional corrosion Application may be by brush or spray Leave the primer to dry at least overnight 12 hours and no longer than one week before application of the topcoat G Finish Coat if using an epoxy based finish coat Before applying the finish coat carefully mix the proper catalyst with the finish coat ba...

Page 33: ...ODEL PCA090480WH CHAPTER 2 SERVICE Section 9 Cleaning and Painting 2 9 March 2013 Page 62 Proprietary Confidential 2013 Twist Inc This page left blank P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 34: ... 4 73 Trouble II Compressor short cycles or shuts off after a few minutes of operation 3 4 74 Trouble III Insufficient cooling 3 4 75 Trouble IV Excessive compressor vibration 3 4 76 Trouble V Compressor rattles when started 3 4 76 Trouble VI Flutter noise when compressor stops 3 4 77 Trouble VII Compressor loses oil oil in sight glass below visual level 3 4 77 Trouble VIII Evaporator coil s freez...

Page 35: ...osition 3 5 88 Valve Stuck in Closed Position 3 5 88 Bulb Miss located 3 5 88 Moisture in Valve 3 5 88 Expansion Valve Field Disassembly Re assembly 3 5 89 Power Element Replacement 3 5 90 Compressor Electrical Phase Rotation 3 5 90 Compressor Operating in a Vacuum 3 5 91 Fusite Failures 3 5 91 Scroll Galling 3 5 91 Compressor Motor Megging 3 5 92 Overcharge of Refrigerant 3 5 92 6 Troubleshooting...

Page 36: ...duction This chapter is to guide service personnel when the Pre Conditioned Air unit needs repair The tables in this section outline the problems likely causes and remedies As it is impossible to foresee all breakdowns this chapter should not be expected to provide answers to every failure P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 37: ...090480WH CHAPTER 3 TROUBLESHOOTING Section 1 Guide to Repair 3 1 March 2013 Page 66 Proprietary Confidential 2013 Twist Inc This page left blank intentionally P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 38: ...tton circuit with meter to verify if a ground exists Make repairs or replace as necessary and test the system 2 Confirm if applicable switch is functioning properly 5 Remote pushbutton switch malfunctioning 3 Check to see if moisture has gotten into the switch box 6 Blower motor VFD fails to energize motor 1 Check control circuit to verify that power is available at the VFD contacts 2 If power is ...

Page 39: ...Vibration and discolored oil could accompany this symptom 1 Connect supply duct to an aircraft 2 Blower motor drawing excessive current due to operation of the unit while it is not connected to an aircraft 2 If in a test mode partially block the aircraft connector or kink hose to simulate aircraft resistance 3 Unit operating at low voltage 1 Stop operations and correct voltage at source 4 Single p...

Page 40: ...box can do this NOTE If the compressor is phased improperly the following will occur a Compressor draws low amperage b Suction and discharge pressures change very little c Rattling or rumbling sound may be apparent d Compressor vibrates excessively 2 Compressor mechanically damaged internally 1 Replace compressor 1 Check for proper airflow on supply side of unit 3 Low load on the refrigeration sys...

Page 41: ...A045480WH CHAPTER 3 TROUBLESHOOTING Section 2 Troubleshooting Basic System 3 2 March 2013 Page 70 Proprietary Confidential 2013 Twist Inc This page left blank P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 42: ...ighten duct to aircraft 2 Check aircraft connector for obstructions and remove any restrictions 3 Flexible duct to aircraft is kinked is obstructed or leaks 3 Repair leaks 4 Air filters dirty or obstructed 1 Clean air filters per instructions in Chapter 2 9 page 1 of this manual 5 Evaporator coil frosted or iced up 1 See Evaporator Coil s Freeze Up Chapter 3 5 page 6 6 Leaking unit to duct and or ...

Page 43: ...ESTED REMEDY 1 Blower motor bearings are worn 1 Repair or replace motor and blower motor contactor 2 Blower wheel out of balance 1 Remove wheel and balance or replace it as required 3 Blower wheel loose on shaft 1 Adjust and retighten blower wheel as necessary 4 Blower wheel hitting or rubbing inlet cone 1 Readjust blower inlet cone or wheel on shaft P r o p e r t y o f A m e r i c a n A i r l i n...

Page 44: ... to overheat Correct phasing of power to compressor 2 Internal thermal switch 4 Compressor rapidly cycles causing motor to overheat Correct cycling malfunction 1 Check for loose connections in circuit 2 Check magnetic contractor to ensure that all phases exist on both line and load sides 3 Manual Motor Starter tripped 3 Check compressor to ensure that motor is not grounded to casing 1 Check overlo...

Page 45: ...ontroller not operating properly 1 Check controller for proper operations and replace if necessary Trouble II Compressor short cycles or shuts off after a few minutes of operation PROBABLE CAUSE SUGGESTED REMEDY 1 Intermittent connections in electrical system 1 Check for loose connections in the electrical system Tighten all connections 2 Evaporator coil frosted or frozen causing low suction press...

Page 46: ...igerant charge as necessary See Chapter 3 6 page 1 6 Excessive refrigerant charge 1 Reclaim excess refrigerant from system See Chapter 3 6 page 9 7 Evaporator coil frosted or frozen causing low suction pressure 1 Evaporator coil s freeze up See Chapter 3 5 page 6 8 Improper superheat adjustment 1 Check superheat and reset thermostatic expansion valve See Chapter 2 8 page 1 9 Evaporator Pressure Re...

Page 47: ...UGGESTED REMEDY 1 Compressor electrically out of phase rotation The compressor will be noisy and vibrate excessively The oil sump will become warm when running backwards 1 Correct phase rotation to A B C NOTE Start up Under conditions of low refrigerant flows low suction pressure such as at start up a rattling sound may emanate from the compressor This is most likely to be heard under such conditi...

Page 48: ...nd check oil level to ensure that oil returns to compressor Once again check level and if necessary add oil accordingly 2 Clogged drier or expansion valve 1 Replace drier See Chapter 3 6 page 2 3 Crankcase oil valve leaks oil oil around compressor base and low crankcase oil level 1 Repair replace valve confirm oil leak has stopped and add proper refrigerant oil as necessary 4 Excessive liquid refr...

Page 49: ... 1 Straighten duct to aircraft 2 Check aircraft connector for obstructions and remove restriction 3 Flexible duct to aircraft kinked obstructed or leaks 3 Repair leaks in gaskets and hoses 4 Air filters dirty or obstructed 1 Clean air filters per instructions in Chapter 2 9 page 1 of this manual 5 Leaking unit to duct and or duct to aircraft connections 1 Check duct connections for loose or poor f...

Page 50: ...1 Replace valve or effected parts as needed See Chapter 3 6 page 4 3 Incorrect expansion valve bulb location 1 Install bulb on suction line at 45 up from bottom ensure good surface to surface contact and ensure that bulb is insulated from outside influence See Chapter 3 6 page 4 4 Low superheat adjustment on expansion valve 1 See Chapter 2 8 page 1 of this manual 5 Restricted or plugged Expansion ...

Page 51: ... at higher supply air temperatures 2 Excessive airflow caused by no restriction on discharge hose 1 Attach duct to aircraft or for testing obstruct aircraft adapter to simulate aircraft resistance 3 Overfeeding of expansion valve 1 Adjust superheat setting of expansion valve and check to see that remote bulb is properly attached to suction line See Chapter 2 8 page 1 and Chapter 3 6 page 4 4 Expan...

Page 52: ...arge 1 Reclaim refrigeration system Replace expansion valve power assembly and re charge system See Chapter 3 6 page 4 1 Check operation of damper motor and associated connections Repair or replace as necessary 2 Check voltage to damper motor 5 Damper motor not operating damper 3 Check for obstructions in operation 6 Obstructed expansion valve 1 Reclaim refrigeration charge repair or replace valve...

Page 53: ...efrigerant 1 Check circuit breakers overloads and magnetic contactors Repair replace components as necessary 2 Check control circuit to ensure that control power is available 3 Check fan cycling switch to ensure status of voltage and condition of switch 4 Check fan blade assembly for proper mounting Retighten hub onto shaft if necessary 4 Condenser fan not operating 5 Repair replace fan motor as n...

Page 54: ... discharge pressure too low PROBABLE CAUSE SUGGESTED REMEDY 1 Lack of refrigerant 1 Reclaim system and check for leaks Re charge system and test 2 Compressor malfunction 1 Replace compressor 3 Ambient temperature too low 1 Do not operate unit 4 Compressor operating backward 1 Change phase rotation to ABC See Chapter 3 6 page 7 P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 55: ...480WH CHAPTER 3 TROUBLESHOOTING Section 4 Troubleshooting Refrigeration System 3 4 March 2013 Page 84 Proprietary Confidential 2013 Twist Inc This page left blank P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 56: ...uspected leak with liquid soap or detergent and bubbles will appear if a leak exists Despite its simplicity the soap bubble method can be extremely helpful in pinpointing a leak that is difficult to locate This method will not pinpoint a very small leak 3 Air in the Refrigeration System If air or other non condensable gases are present in the system they will tend to move toward and collect at the...

Page 57: ...rst remove excess dirt from condensers with soft bristled paintbrush Second use air or water to remove any loosened residue Apply water or airflow so that residue is directed away from the coil instead of into the coil In a severe environment use a non acid alkaline based coil cleaning solution as described below UWARNINGU THEN USING AIR NOT MORE THAN 30 PSIG FOR CLEANING IT IS VERY IMPORTANT TO F...

Page 58: ...art to open at 52 psia G The valve can be adjusted by the spring tension on top of the valve Adjust the airflow to get the suction pressure higher or lower to test the hot gas valve setting G Remove the service gauge manifold connection and cap the Schrader valves Return the unit to service 8 Expansion Valve Malfunction A Charge Lost The power element of an expansion valve consists of the remote b...

Page 59: ... compressor crankcase excessive foaming will be seen C Valve Stuck in Closed Position A warm supply air temperature may indicate an expansion valve that is stuck When this happens the suction pressure will be low D Bulb Miss Located Clamp the expansion valve bulb to the horizontal suction line near the evaporator outlet Clean the suction line thoroughly before clamping the remote bulb in place Ins...

Page 60: ...then blowing it off with clean dry compressed air F To re assemble valves screw seat into body Use hand pressure only since it does not require a heavy torque on this small knife edge joint UCAUTION U BE SURE HEXAGON CORNERS OF SEAT DO NOT PROTRUDE INTO PUSHROD HOLES G Slip the pin and carrier which have been pressed together at the factory into the body Before tapping these parts together check t...

Page 61: ...reign materials or nicks that might prevent a leak tight joint A few drops of refrigerant oil on the element threads will facilitate easy assembling and removal K Return the superheat adjustment stem to its original position This can be done by turning the stem counter clockwise until a ratcheting sound is heard then clockwise the number of turns recorded prior to disassembly L Replace the seal ca...

Page 62: ...perating in a Vacuum UCAUTION U OPERATING THE SCROLL COMPRESSOR IN A VACUUM WILL RESULT IN ELECTRICAL OR MECHANICAL DAMAGE TO THE COMPRESSOR The scroll compressor can pull into a vacuum much quicker than a reciprocating compressor There are two failures that will occur due to running the compressor in a vacuum A Fusite failures The fusite terminals will arc internally which results in a motor fail...

Page 63: ...r motor windings The use of a megger with a voltage of more than 500 volts is not recommended for insulation systems of 600 volts or less because of the potential for damage to the insulation system If readings below these values are measured evacuate the compressor to insure complete dehydration bring it back up to a positive pressure with refrigerant and remeg It may be necessary to clean the te...

Page 64: ... digital multi meter DMM This is the AC power supply for the ALC and should be within 10 of 24 VAC If proper voltage is applied but the above conditions do not occur either the software is not loaded correctly or the ALC is possibly defective A red LED labeled POWER on the right hand side of the ALC will show whenever power is being provided to the ALC NOTE The I O Flex 6126 is protected by intern...

Page 65: ...es second Brownout Alternating There are other LEDs that provide information of the condition of the unit Digital Output Status Lights when the digital output is activated Analog Output Status Lights when the analog output is activated Rx Lights when the module receives data from the network segment there is an Rx LED for ports 1 and 2a Tx Lights when the module transmits data over the network seg...

Page 66: ...rminal block Check the wiring to be sure it is correct The input point for the Current Transducer CT is a 4 to 20 milliamp input When the Start mode relay is closed the ALC should begin to start the unit by signaling the VFD to start the blower If the start mode relay is closed and the unit does not start the circuit may not be correct The other input points are digital inputs If the switch is clo...

Page 67: ...nel will turn on and will not clear when the stop button is depressed To clear the fault turn the power off for 10 seconds and then on or push the reset button on the smoke detector 7 Phase Monitor If the phase monitors trips the 24 volt control power is interrupted This allows the ALC controller to remain in operation but disables all discrete output points The red fault light will turn on Reset ...

Page 68: ...ary Confidential Page 97 2013 Twist Inc CHAPTER TITLE SECTION PAGE 1 Major Repair Removal for Major Repair 4 1 99 Removal for Overhaul 4 1 99 Replacement Parts 4 1 99 2 Shipping Procedures Shipping Procedure 4 2 101 6 Storage Procedures Storage Procedure 4 3 103 P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 69: ...CHAPTER 4 REMOVAL SHIPPING AND STORAGE Table of Contents Table of Contents March 2013 Page 98 Proprietary Confidential 2013 Twist Inc This page left blank intentionally P r o p e r t y o f A m e r i c a n A i r l i n e s ...

Page 70: ...component is not covered in this manual the component should be removed and returned to the manufacturer or other authorized facility for replacement 3 Replacement Parts The following list of parts is reprehensive of items used in this unit If any one item needs replacement the list will guide the user to procure the right parts These parts are available through Twist Inc 47 South Limestone Jamest...

Page 71: ...tection Modules 24 VAC Bitzer PC9013 4 Transducer Pressure 0 750 PSIG IFM Efector A CP 1 10 NW BB 2 Temperature Sensor 10 4888 Di h AGI D4120 1 Smoke Detector System Sensor 316 02 22A30AC 1 2 Filter 22 X 30 x 2 Alum AAFG FD63B225L 1 CB Main 225 Amps Thermo Mag Siemens S17FD60 1 CB shunt trip 24VAC Siemens MBS63EH 630 G 1 CB Contactor Starter 63 Amps 3P EE Controls CB4A2PD 1 Circuit Breaker 4 Amps ...

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