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Service Manual 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

for the 

SRL Refrigerated Air Dryers 

 

Models: SRL-250 to 6000 (60Hz) 

              SRL-120 to 1800 (50Hz) 

 
Document PN#: 02250___-___ 

Summary of Contents for SRL Series

Page 1: ...Service Manual for the SRL Refrigerated Air Dryers Models SRL 250 to 6000 60Hz SRL 120 to 1800 50Hz Document PN 02250___ ___ ...

Page 2: ... 3 1 The Air Circuit 14 3 1 1 Air To Air Heat Exchanger 15 3 1 2 Air To Refrigerant Heat Exchanger 15 3 1 3 Demister Separator 15 3 1 4 Condensate Chamber 15 3 1 5 Dew Point Temperature Sensor 16 3 1 6 Condensate Level Sensor 16 3 2 Refrigeration Circuit 16 3 2 1 The Thermal Mass Concept 17 3 2 2 Compressor 17 3 2 3 Condenser 18 3 2 4 Refrigerant Filter 18 3 2 5 Expansion Device 19 3 2 6 Refrigera...

Page 3: ... 35 9 1 SRL 250 35 9 2 SRL 325 to 6000 35 9 3 Drain Operating Mode Parameter D3 37 9 4 Manual Drain Activation 37 10 Alarms Warnings 38 10 1 Alarm Warning List 38 10 2 Troubleshooting Alarms Warnings 39 10 2 1 HP High Pressure Alarm 39 10 2 2 LP Low Pressure Alarm 40 10 2 3 Ld Low Dewpoint Alarm 41 10 2 4 Ht High Discharge Temperature Alarm 42 10 2 5 Lt Low Evaporator Temperature Alarm 43 10 2 6 C...

Page 4: ...ort 51 10 3 2 Resetting the Alarm History Report 52 10 5 Remote Monitoring Option 53 11 Recommended Maintenance 54 11 1 Maintenance Schedule 54 11 2 Preventative Maintenance Kits 55 12 Maintenance Procedures 56 12 1 Replacing a Pressure Switch 56 12 2 Replacing the Drain Valve 56 12 3 Cleaning the Condensate Strainer 56 12 3 Replacing the Control Board 57 12 6 Adjusting the Hot Gas Bypass Valve 58...

Page 5: ...yer depending on the needs and wishes of the end user In direct expansion a k a continuous mode the refrigerant compressor runs continuously and the dryer handles reduced heat loads by redirecting refrigerant away from the heat exchanger using a bypass valve to maintain a constant outlet dewpoint This is the simplest mode of operation however does not save any energy at part load In cycling mode t...

Page 6: ...2250169 827 575 02250169 452 460 02250169 816 575 02250169 467 460 02250169 828 575 02250169 453 460 02250169 817 575 02250169 468 460 02250169 829 575 02250169 454 460 02250169 818 575 02250169 469 460 02250169 830 575 02250169 455 460 02250169 819 575 02250169 470 460 02250169 831 575 02250169 456 460 02250169 820 575 02250169 471 460 02250169 832 575 1 Maximum rated flow at CAGI conditions of 1...

Page 7: ...0169 410 AC 2 29 02250169 422 WC 2 28 02250169 411 AC 2 89 02250169 423 WC 2 77 02250169 412 AC 3 60 02250169 424 WC 3 49 02250169 413 AC 3 52 02250169 425 WC 3 39 02250169 414 AC 4 28 02250169 426 WC 3 87 02250169 415 AC 5 24 02250169 427 WC 5 05 02250169 416 AC 6 91 02250169 428 WC 6 20 02250169 417 AC 9 86 02250169 429 WC 8 87 02250169 418 AC 10 94 02250169 430 WC 10 12 02250169 419 AC 15 25 02...

Page 8: ...mm 2800 1000 2300 2500 Min psig barg Max psig barg Min F C Max F C Min F C 113 45 Max F C 158 70 167 75 158 70 Min F C Max F C On psig barg Off psig barg Qty 4 5 6 psig barg Code All parameters refer to operating conditions at zero air flow R407C 35 6 2 48 2 9 33 8 1 66 7 4 6 Control Software Release dt 3 460V 3ph 60 Hz 406 28 203 14 276 19 41 5 High Pressure Switch Setting Standard Supply Voltage...

Page 9: ...g Min F C Max F C Min F C 131 55 140 60 131 55 Max F C 176 80 185 85 176 80 Min F C Max F C Qty 4 5 6 psig barg Code All parameters refer to operating conditions at zero air flow 33 8 1 66 7 4 6 62 4 4 3 R407C 406 28 41 5 35 6 2 48 2 9 460V 3ph 60 Hz dt 3 Control Software Release High Pressure Switch Setting Supply Voltage Dew point temperature Number of Heat Exchangers 2 3 Suction Temperature Dis...

Page 10: ... Min C 60 50 60 50 45 Max C 85 75 85 75 70 Min C Max C On barg Off barg Qty 4 5 6 barg Code All parameters refer to operating conditions at zero air flow R407C 1 1 3 18 2 5 2800 1500 85 60 70 2 15 1 4 6 50 Control Software Release dt 3 400V 3ph 50Hz 28 14 19 5 3 High Pressure Switch Setting Standard Supply Voltages Available 1 7 45 400V 3ph 50Hz 3 4 3 5 3 18 Number of Heat Exchangers 2 Dew point t...

Page 11: ...barg Max barg Min C Max C Min C 55 60 55 Max C 80 85 80 Min C Max C Qty 4 5 6 barg Code All parameters refer to operating conditions at zero air flow Control Software Release dt 3 NA R407C 4 8 4 6 15 1 1 85 High Pressure Switch Setting 28 Standard Supply Voltages Available 400V 3ph 50Hz R407C 2 3 3 18 3 5 4 1 15 45 70 2 5 85 60 3 3 Refrigerant Number of Heat Exchangers Expansion Capillaries Hot Ga...

Page 12: ...588 AC 66 5 1689 WC 62 5 1588 AC 67 8 1722 WC 62 5 1588 AC 67 8 1722 WC 62 5 1588 AC 67 8 1722 WC 62 5 1588 AC 81 0 2057 WC 62 5 1588 AC 81 0 2057 WC 62 5 1588 AC 87 0 2210 WC 63 6 1615 AC 87 0 2210 WC 63 6 1615 145 320 1148 1819 706 806 1008 39 7 1190 2624 2258 88 9 1100 2425 830 1830 1808 71 2 730 1610 71 6 690 1521 670 1477 580 1279 490 49 0 1245 1080 370 43 2 1097 816 551 250 45 2 240 529 31 7...

Page 13: ... AC 1722 67 8 WC 1586 62 4 AC 1722 67 8 WC 1586 62 4 AC 1722 67 8 WC 1586 62 4 AC 2048 80 6 WC 1586 62 4 AC 2208 86 9 WC 1616 63 6 AC 2208 86 9 WC 1616 63 6 39 6 39 6 31 7 806 1007 49 0 45 9 1007 1521 1830 2425 830 1100 507 529 540 551 1036 1080 1279 1477 230 240 245 250 470 490 580 670 690 1657 1807 1245 1166 Weight 2623 1190 Width Depth 320 145 27 8 706 41 2 1046 945 183 83 27 7 703 22 1 562 37 ...

Page 14: ...ng the dryer The Refrigeration Circuit Consisting primarily of B Air to Refrigerant Heat Exchanger E Refrigerant Compressor F Hot Gas Bypass G Condenser H Refrigerant Filter and I Expansion Device The refrigerant passes through the Air to Refrigerant Heat Exchanger B where it absorbs heat from the air and evaporates into a gas It then passes through the Refrigerant Compressor E where it is compres...

Page 15: ...drain it from the system The Air to Air and Air to refrigerant heat exchangers are an aluminium fin design which combine high surface area and therefore efficient heat transfer with low pressure drop and minimum corrosion The air circuit is insulated with special TSI Thermal Shield Insulation polystyrene based offering a very high thermal retention for even further improved efficiency There are th...

Page 16: ...ons to facilitate removal if needed 3 1 3 Demister Separator All models are equipped with a Slowflow demister type moisture separator to remove the condensed liquids from the compressed air The liquid droplets impact the stainless steel fibers of the demister and coalesce into larger drops where they are pulled into the Condensate Chamber by gravity The demister combines a high efficiency with a l...

Page 17: ... loss drain operation so no level sensor is required 3 2 Refrigeration Circuit All models have the option of operating in continuous mode or operating in cycling mode on a thermal mass principal For an overview of the thermal mass concept refer to 3 2 1 below For full details on both operation options refer to Section 8 The main components of the refrigeration circuit are the Compressor the Conden...

Page 18: ...2 Compressor All models with the exception of the SRL 250 are equipped with compliant scroll refrigerant compressor with a three phase motor These compressors are maintenance free and installed on vibration damping mountings The compressor reduces the pressure in the evaporator ensuring the refrigerant evaporates at the correct pressure and therefore temperature It compresses the evaporated refrig...

Page 19: ...ted from the rest of the dryer thereby allowing maintenance even when the dryer is in operation The heat absorbed by the refrigerant in the Air to Refrigerant Heat Exchanger and produced during compression is rejected to the ambient in the condenser If the condenser is unable to reject all the heat absorbed i e due to fouling the refrigerant system will overheat and over pressure resulting in shut...

Page 20: ...el R407C furthermore features a high COP Coefficient of Performance thereby ensuring that the dryer s power consumption is kept to a minimum 3 2 7 High Pressure Switch Settings On 406 psig 28 barg Off 305 psig 21 barg Shuts down the dryer in the event of overpressure of the refrigerant system Installed at the compressor outlet When it trips the display will show the HP High Pressure alarm and the ...

Page 21: ...nt at start up may be required depending on the cooling water temperature 3 2 11 Hot Gas Bypass Valve Setting Max 66 7 psig 4 6 barg Min 62 4 psig 4 3 barg Maintains a constant refrigerant pressure in the compressor suction line to account for changes in the heat load As the heat load into the dryer decreases less heat is transferred to the refrigerant in the Air to Refrigerant Heat Exchanger and ...

Page 22: ... some liquids this prevents large volumes of liquids from reaching the inlet The refrigerant mixture in both gas and liquid form enters the separator where the liquid falls to the bottom and the gas moves to the top By pulling the refrigerant from the top only refrigerant in gas form reaches the compressor In addition to ensure proper lubrication of the compressor lubricant which collects in the a...

Page 23: ...and a digital display In addition the microprocessor also Records and displays the last 8 warnings or alarms Records the working hours of the dryer and of the refrigerant compressor Provides a Service Required warning at a pre set interval Controls the cycling operation of the refrigerant compressor SRL 325 larger when in Cycling mode and Controls operation of the condensate drain The microprocess...

Page 24: ...r Ground J1 3 24V Power 24Vac J1 5 ID1 High Pressure Switch HP Alarm J1 8 ID2 Compressor Protection CP Alarm J1 11 ID3 Remote On Off J3 1 IDC2 Common Ground J3 2 ID4 Drain Level Sensor J3 3 5V Power Input to Drain Level Sensor SRL 1600 to 6000 60Hz and SRL 630 to 1800 50Hz only SRL 325 to 6000 60Hz and SRL 120 to 1800 50Hz only 4 2 2 Outputs All outputs are digital Digital Outputs J1 J3 J1 4 NO1 C...

Page 25: ...ange 10o C to 90 C 1 C Temperature Sensor B3 Reading Range 0 C to 150 C 5 C Input for HP LP CP Remote On Off 24 Vac Output for Drain Level Sensor 5Vc c 15mA Output to KM1 YV1 YV2 VY3 Vmax 30Va c Imax 1A Output for Alarm Warning Signal Vmax 30Va c Imax 1A 4 2 4 User Interface The main control panel of the dryer consists of On Off Switch with door block 7 segment 3 digit digital display 4 LED Lights...

Page 26: ...t connected to a power supply o Green indicates the dryer is operating Warning LED o Red indicates the dryer has a warning or alarm Drain LED o Green indicates the drain valve is open Energy Saving LED o Green indicates that the parameters for cycling the refrigerant compressor off have been met The refrigerant compressor is currently off and the dryer is therefore saving energy Not applicable to ...

Page 27: ...Scrolls down to next alarm or item o In Parameter Menu Scrolls down to previous parameter or decreases a value when modifying a parameter Drain Exit o Standard Function Manually operates the drain valve according to timed mode settings See Section 9 o In Alarm Menu Exits the current alarm item or menu o In Parameter Menu Exits the current parameter or menu On Off Enter o Standard Function Turns th...

Page 28: ...current and ground circuit breaker 0 3 Amps Connect the inlet and outlet compressed air piping connections to the dryer using the correct ports as indicated on the dryer SRL 250 through 1200 have BSP threaded inlet and outlet ports BSP to NPT adapters are provided loose and must be installed Attempting to thread in NPT pipe into the BSP ports will damage to the threads Install a bypass line around...

Page 29: ...n and around the dryer do not contain solid or gaseous contaminants All compressed and condensed gases can generate acids or chemical products which may be aggressive against the aluminium heat exchanger or the other components inside the dryer Take particular care with sulphur ammonia chlorine and installations in marine environments Protect the dryer from instantaneous or continuous flows in exc...

Page 30: ...rant Compressor 3 2 2 starts and the digital display shows the B1 temperature reading dew point temperature On three phase units if the phases are inverted the compressor and the fan will rotate in the wrong direction In this case a The scroll compressor is not displacing any refrigerant It will be noisy and the dryer will vibrate Since the dryer is not producing any cooling effect after 15 minute...

Page 31: ...ess the ON OFF button or provide the command via an external control system as described above The display will show the B1 dewpoint temperature sensor reading and the refrigerant compressor will turn on To turn the dryer OFF press the ON OFF button or provide the command via an external control system The display goes off and the refrigerant compressor stops The dryer can also be turned OFF remot...

Page 32: ...1 Service Required Warning Interval 1 hrs x 103 1 999 6 C7 3 Dryer Operating Mode 3 5 CYC Con CYC D1 Drain Duration Time open sec 1 60 5 D2 Drain Interval Time closed sec 1 900 120 D3 4 Drain Operation Mode 4 5 0 CAP 2 Con 0 CAP 1 Parameters B3 B7 B9 are passcode protected and cannot be changed or reset without the proper code Refer to Section 10 3 10 4 for further information 2 Parameter B8 only ...

Page 33: ...ithout first pressing Enter to save your changes you will exit without saving and the parameter will revert to it s previous value Note that once inside the parameters menu the meaning of the buttons is different from the standard operation See section 3 2 It is not possible to Turn the dryer On or Off Reset a warning or alarm Display the alarm report Activate the drain valve Once in the parameter...

Page 34: ...t the refrigerant circuit be constantly controlled to maintain a steady temperature and therefore pressure in the evaporator Ultimately the temperature in the evaporator is maintained at about 35 to 39 degrees Fahrenheit just above freezing In this way the dryer provides the lowest possible dewpoint while keeping the condensate in liquid form so it can be removed 8 1 Continuous Mode When Parameter...

Page 35: ...ting the compressor is stopped and the dryer is saving energy It should be noted that there is no specific temperature at which the compressor will turn off The microprocessor must also consider other factors such as the amount of time since the compressor was last turned off and therefore may delay turning the compressor off regardless of the temperature of the evaporator In these cases the Hot G...

Page 36: ... Sensor 3 1 6 continuously monitors the level of condensate closing the contacts and sending a signal to the microprocessor digital input ID4 when it senses liquid The microprocessor opens the solenoid drain valve coil YV3 when it gets a signal from the Level Sensor continuously for 30 seconds Parameter D4 Drain Open Delay The condensate is then discharged from the Condensate Chamber through the s...

Page 37: ...oes into alarm drE flashes on the display and the microprocessor automatically changes to timed operation in accordance with the interval and duration settings in User Parameters D1 D2 When the Level Sensor stops sensing liquid the microprocessor will automatically change back to zero air loss operation If desired the user can force the drain on the SRL 325 through 6000 to always operate in timed ...

Page 38: ...itive mode was set on this model the microprocessor would get no signal to open and would keep the valve closed permanently Note that when the drain is set to Continuous Deactivated Mode the drain solenoid valve must be removed and an external self controlled condensate drain must be installed The external drain can be powered through the board output NO3 24V or directly from the electrical cabine...

Page 39: ...drE 5 Drain Error Warning None Changes to Timed Mode dSE 7 Dewpoint Sensor Error B1 Warning None Trips common alarm rSE 8 Evaporator Temp Sensor Error B2 Warning None Trips common alarm Sr 6 Service Required Warning None Trips common alarm The control board is provided with an alarm relay with NO NC contacts The relay is normally energized once the controller is powered in order to provide an alar...

Page 40: ...essure with a gauge Remedy Replace the detective component 4 Excessive thermal load on the dryer due to excessive air flow rate and or air inlet temperature Can be confirmed using the instructions in Section 13 Remedy Improve the efficiency of the aftercooler on the compressor install an additional or larger air or water cooled aftercooler upstream the dryer or install a larger dryer If the overlo...

Page 41: ...w 22 psig Remedy Check or leaks at welds threaded connections schrader valve caps and joints of the condenser and evaporator Repair the leak pull the system to deep vacuum and charge the dryer with the correct amount of refrigerant as specified in the Section 2 3 2 A defective low pressure switch is giving a wrong signal to the controller Can be confirmed by checking the evaporator pressure with a...

Page 42: ...se the ambient temperature in the room or duct the air for the condenser from a warmer source Alternately you can partially cover the condenser coils in order to reduce the air flow across them thereby reducing the cooling effect 3 A defective fan pressure switch is causing the condenser fan to stay on all the time causing excessive cooling of the refrigerant Remedy Replace the defective component...

Page 43: ...ction 2 3 2 A clogged refrigerant filter is restricting the amount of refrigerant getting to the evaporator causing it to absorb too much heat which causes a compressor discharge temperature in excess of 248o F This can be confirmed by measuring the temperature drop across the filter which should not exceed a few degrees Remedy Replace the clogged component 3 A clogged capillary tube is restrictin...

Page 44: ...ase the ambient temperature in the room or duct the air for the condenser from a warmer source Alternately you can partially cover the condenser coils in order to reduce the air flow across them thereby reducing the cooling effect 2 A defective fan pressure switch is causing the condenser fan to stay on all the time causing excessive cooling of the refrigerant Remedy Replace the defective componen...

Page 45: ...gh Amps causing overheating of the windings Remedy Ensure that the electrical connections at the compressor terminal and the contactor are correctly attached and tight To Reset Find the cause of the alarm and fix the problem Press ALARM RESET to clear alarm Power restored to alarm relay Warning Light goes off Dryer remains OFF Display clears Press ON OFF to restart dryer Notes Alarm can only be cl...

Page 46: ...iod of time this alarm can be avoided by partially opening the air by pass line to reduce the load to the dryer Please note that this will significantly increase the downstream dew point 3 The dewpoint temperature sensor B1 is out of calibration causing a high reading This can be confirmed by using a temperature gun to check the temperature at the location of the dew point probe and comparing it t...

Page 47: ...of the blockage restriction or back pressure and fix it 2 Defective condensate level sensor gives a signal indicating condensate is present even if there is none Remedy Replace the defective component 3 Defective condensate drain valve Remedy Replace the defective component To Reset The drain will automatically return to Capacitive Aero Air Loss Mode operation when the level sensor stops sensing l...

Page 48: ... goes off Notes Alarm can only be cleared if sensor reading is within limits 10 2 11 Evaparator Temperature Sensor Error Warning What it means Temperature sensor B2 evaporation temperature is short circuited open or a signal outside it s range 10o C to 90 C What it does If dryer was in Cycling Operating Mode it is automatically switched to Continuous Mode Cuts power to the alarm contacts Turns on ...

Page 49: ...ay To Reset Press ALARM RESET Power restored to alarm relay Warning Light goes off for 24 hours To reset the alarm for another 6000 hours contact Sullair or your authorized Sullair distributor and ensure the dryer filters are inspected and maintained in accordance with the schedules in their respective user guides The alarm reset Parameter B3 and it s interval Parameter B9 are locked and can only ...

Page 50: ...e value will change to Yes for a moment and then change back to no The alarm has now been reset 5 Press Exit to exit the parameter The display will show you are at Parameter B3 6 Press Exit again to exit the User Parameter Menu The display will show the dewpoint if the dryer is on OFF if the dryer is off or rOF if the dryer is in Remote Off Mode Please Note The purpose of the Service Required warn...

Page 51: ...play will show you it s value is 6 6000 hours The value cannot be changed by pressing the Up or Down buttons 4 Press the Up Enter buttons simultaneously for 5 seconds This unlocks the parameter so it can be modified 5 Press the Up or Down buttons to change it s value min 1000 hours max 999 000 hours 6 Press Enter to save your changes and exit the parameter The display will show you are at Paramete...

Page 52: ...view the Alarm History Report press the Alarm Report Button for 5 seconds The alarm records are displayed starting from the oldest If there are alarms or warnings recorded the display will shows ALx where x is the number of alarms recorded up to a maximum of 8 If there are no alarms or warning recorded the display temporarily shows three dashes To scroll through the alarms and warnings press the U...

Page 53: ...nter buttons simultaneously for 5 seconds The value will change to Yes for a moment and then change back to no The alarm has now been reset 5 Press Exit to exit the parameter The display will show you are at Parameter B7 6 Press Exit again to exit the User Parameter Menu The display will show the dewpoint if the dryer is on OFF if the dryer is off or rOF if the dryer is in Remote Off Mode Please N...

Page 54: ...ding Management System To do so an optional RS485 serial card is fitted to the back of the microprocessor This allows direct connection to a BMS using the MODBUS RTU protocol without the need for any intermediate Gateway Once connected to the BMS it is possible to achieve Visualization of Dew point other temperatures Alarms Working hour counters Control of Dryer on off Alarm reset if allowed ...

Page 55: ...SRL Service Manual Revision 00 July 2007 Page 54 of 56 11 Recommended Maintenance 11 1 Maintenance Schedule ...

Page 56: ...preventative maintenance can ensure continuous trouble free operation without unexpected alarms or failures Three year preventative maintenance kits are available which include Pressure switches HP LP fan Temperatures probes B1 B2 B3 Fan compressor contactors Solenoid Valve Coils YV1 YV2 Refer to the User Guide supplied with the dryer for further details ...

Page 57: ...eep it in position while screwing the switch onto the valve 12 2 Replacing the Drain Valve Loosen the 3 piece union Unscrew the electrical connector Remove the fixing nut Remove the old coil and install the new one Replace the fixing nut Reattach the electrical connector Tighten the 3 piece union 12 3 Cleaning the Condensate Strainer The internal strainer of the drain valve should be cleaned at le...

Page 58: ...onnect the temperature sensor wires Disconnect the level sensor SRL 325 to 6000 ONLY Pull firmly on the connector being careful not to damage it Unscrew the six screws holding the board in place Replace the old board with the new one Reinstall the temperature sensors wires in the same locations Temperature sensor connections Level sensor connection Electrical supply digital input output connection...

Page 59: ...gerant tube at the outlet of the evaporator Make sure to use as short a hose as possible on the gauge to avoid refrigerant losses which may affect the dryer performance especially on smaller models Remove the cap on the Hot Gas Bypass Valve To increase the evaporation pressure turn the regulating screw clockwise loading the internal spring To decrease the evaporation pressure turn the regulating s...

Page 60: ...will fluctuate considerably with time Please ensure that the maximum temperatures and air flow and the minimum pressure is used as these will correctly reflect the worst case scenario Do not use simply the instantaneous or average values If the operating parameters only exceed the maximum capacity of the dryer by a relatively small amount often the dryer will continue to operate however the outlet...

Page 61: ...90 100 110 113 Correction Factor A 1 30 1 23 1 16 1 08 1 0 92 0 89 Air Inlet Temperature Correction Factor B Air Inlet Temperature o F 90 100 110 120 130 140 Correction Factor B 1 26 1 0 80 0 63 0 50 0 38 Air Inlet Pressure Correction Factor C Ambient temperature o F 50 80 100 125 150 170 190 200 Correction Factor C 0 76 0 93 1 1 03 1 11 1 14 1 16 1 17 ...

Page 62: ... ask him to confirm the actual operating conditions when the alarm occurs and after consulting with his plant manager he tells you the following Air Flow cfm 300 cfm Ambient Temperature o F 100 o F Inlet Air Temperature o F 120 o F Inlet Air Pressure psig 125 psig Using the above correction factor tables you quickly find the three Correction Factors are A 1 B 0 63 C 1 03 Using your calculator and ...

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