McQuay MicroTech II, Operation & Maintenance Manual

Page 1: ...l AHV AHR Ceiling Mounted Model AZV AZU AZR Floor Mounted Self Contained Air Conditioner Before unit commissioning please read this publication in its entirety Develop a thorough understanding before starting the commissioning procedure This manual is to be used by the commissioner as a guide Each installation is unique only general topics are covered The order in which topics are covered may not ...

Page 2: ...ity 19 Networked Setpoint Shift Capability 19 Networked Space Temperature Sensor Capability 19 LUI Setpoint Offset Adjustment 20 Remote Wall Mounted Sensor with 3 F Adjustment optional 20 Remote Wall Mounted Sensor with 55 F to 85 F Adjustment optional 20 Effective Setpoint Calculation Examples 20 PI Control Loops 21 Discharge Air Temperature Control 21 PI Control Parameters 22 Proportional Band 2...

Page 3: ...Indication 28 Condensate Overflow Indication optional 28 Space Coil DX Temp Sensor Failure 28 Outdoor Temp Sensor Failure 28 Table 1 Abbreviations Index of Meaning of Abreviations Abreviations LED Light Emitting Diode LUI Local User Interface MCLL Mechanical Cooling Low Limit NEC National Electrical Code OA Outdoor Air OAD Outdoor Air Damper OADE Energize Exhaust Fan OAD Setpoint OADH OAD Min Posi...

Page 4: ...zards can result in death or severe personal injury CAUTION identifies unsafe practices that can result in personal injury or product and property damage Improper installation adjustment service maintenance or use can cause explosion fire electrical shock or other conditions which may result in personal injury or property damage This product must be installed only by personnel with the training ex...

Page 5: ...en Off mode and running Application Mode Input The On Stop LED will be off when the UVC is in the off mode GETTING STARTED ThismanualcontainsinformationregardingtheMicroTechII control system used in the AAF HermanNelson Unit Ventilator product line It describes the MicroTech II components input output configurations field wiring options and requirements and service procedures For installation and ...

Page 6: ...T OFFSET Most likely this is due to the security feature being used If the security feature is set higher than level 0 then some LUI functionality is locked out To ensure this is not the problem enter the level 0 password then try again to use the LUI When using the 3 F 1 7 C remote wall sensor any setpoint offset adjustment made at the LUI will cause the UVC to override and ignore the remote wall...

Page 7: ... Override Input Adjusting this variable is only intended for troubleshooting once you RW x 햲 are done you must cycle unit power to clear this variable and return the UVC to normal operation Occupied Cooling Setpoint OCS Adjust occupied cooling setpoint RW x 73O F 23O C Standby Cooling Setpoint SCS Adjust standby cooling setpoint RW x 77O F 25O C Unoccupied Cooling Setpoint UCS Adjust unoccupied co...

Page 8: ...l BI 1 Configuration Set the function of external binary input 1 0 unoccupied RW x 0 1 dewpoint humidity switch 햴 External BI 3 Configuration Set the function of external binary Input 3 0 ventilation lockout RW x 0 1 exhaust interlock Fan Cycling Configuration Set if IAF cycles switches off during occupied bypass and RW x 2 standby mode 2 no cycling 3 cycle IAF Filter Alarm Enable Set filter alarm...

Page 9: ...ere all the actual work takes place within each state the UVC enables PI loops and other logic sequences required to control unit ventilator operation within that particular state while other functions and PI loops not needed during that state may be disabled Conditional jumps or transitions are the Not all states or modes are available for all UV configurations and some states such as Active Dehu...

Page 10: ...cupancy mode Special purpose unit modes i e Purge Pressurize and De pressurize modes accessed via a network connection can force the UVC to perform special functions during which the UVC will appear to be in the Off mode See Special Purpose Unit Modes and the UVC Unit Mode Priority sections for more information The UVC will remain in this state until one of the transition out conditions become tru...

Page 11: ...t of UVC Mode Emergency Heat Super State Figure 10 Emergency Heat State Diagram Full Heat State State Number 7 The Full Heat state is the normal state that the UVC will go into when Emergency Heat mode is active Transition Heat Available into State Operation When Emergency Heat mode becomes active the within State UVC will go into 100 heating until the space temperature raises to the EHS plus a fi...

Page 12: ...true when an IAT or DAT sensor fault exists see Unit Faults HEAT MODE SUPER STATE When in Heat mode the UVC will use primary heat electric heat as neededtomaintaintheeffectiveheatingsetpoint seeSpaceTemperature Setpoints The LUI or a network connection can be used to force the unit into the Heat mode Additionally the UVC when set to Auto mode can automatically force the unit into the Heat mode as ...

Page 13: ...IAT or DAT sensor fault during the Heat mode will cause the UVC to make the Cant Heat state active Transition Heat Available into State Operation When the Cant Heat state becomes active no heating within State or ventilation will take place The OA damper will be closed The UVC will remain in this state until one of the transition out conditions become true or until one of the super state transitio...

Page 14: ...n UVC Mode Cool AND UVC Mode Auto of out OR Super State UVC Mode Auto AND Space Temp Cold AND Mech PI Saturated Low AND Econ PI Saturated Low Figure 13 Cool Mode Super State Diagram COOL MODE SUPER STATE When in Cool mode the UVC will use primary cooling economizer and secondary cooling mechanical DX as needed to maintain the effective cooling setpoint see Space Temperature Setpoints The LUI or a ...

Page 15: ...ling Available out of State OR Space High CO2 OR DAT VCLL OR Econ Timer ExpiredANDEcon PI Saturated High AND MechCool Available OR Econ Available AND Mech Cooling Available Figure 14 Econ State Operation Occupied Mode and Auto Fan Figure 15 Econ Mech State Operation Occupied Mode and Auto Fan Econ Mech State state number 1 The Econ Mech state is a normal state that the UVC can go into when Cool mo...

Page 16: ...lable and secondary cooling compressor is available DA Heat State state number 4 The DA Heat state is a normal state that the UVC can go into when Cool mode is active The DA Heat state is typically active when reheat is required to maintain DATS while maintaining the required OA damper position The DA Heat state can also be active if the optional CO2 DCVfeatureisprovidedandCO2 levelsarehigh requir...

Page 17: ...s state until one of the transition out conditions become true or until one of the super state transition out conditions becomes true Transition OAD Alarm AND Low Limit Timer Expired out of State OR Heat Available Notes The OAD is considered to be in alarm when the OAD is forced below the active minimum position in the Low Limit state This is not an actual unit alarm or fault condition but only a ...

Page 18: ...e Standby Occupied Don t Care Occupied Unoccupied Don t Care Unoccupied 햲 Null default 햳 Contacts Open Occupied Occupied Null default Contacts Closed Unoccupied Unoccupied 햲 Table 11 Occupancy Mode Priority Networked Occupancy Sensor network variables along with the Unoccupied and Tenant Override binary inputs are used to determine the Effective Occupancy Priority Result Emergency Override Remote ...

Page 19: ...emporarily force the UVC into the bypass occupancy mode from unoccupied mode REMOTE WALL MOUNTED SENSOR STATUS LED The optional remote wall mounted sensors each include a UVC status LED This status LED aids is diagnostics by indicating the UVC occupancy mode and fault condition Indication LED Operation Occupied On Continually Unoccupied On 1 sec Off 9 sec Bypass On Continually Standby On 9 sec Off...

Page 20: ...t Input variable If it is intended that a network connection will be used to adjust the Setpoint Offset Input variable then you must not use the optional remote wall mounted sensor with 3O F adjustment If it is intended that the LUI will be used by room occupants to adjust the Setpoint Offset then you must not use the optional remote wall mounted sensor with 3O F adjustment If you have the optiona...

Page 21: ...rature Setpoint Output PI Control Loops The MicroTech II UVC uses PI loop control for heating cooling and ventilation processes within the unit ventilator As many as six PI algorithmsmaybeusedforsoftwaremodel04 dependentupontheunit Table 15 PI Loop List Figure 17 PI Loop Graphic for CO2 Figure 18 Cascading PI Loop Graphic 1 Primary Heat Figure 19 Cascading PI Loop Graphic 2 Primary Cool Economizer...

Page 22: ...ing that is too large See Figure 22 will cause an offset between the actual measured oscillation center and the setpoint A small offset is not necessarily a problem as most systems haveasmall natural offsetandtheIntegralfunctionwillautomatically work to eliminate or reduce this effect Figure 22 Proportional Band too Large In general it is best to start with relatively large Proportional Band setti...

Page 23: ...ositions based upon the operation of the IAF This allows the ability for each unit to be field configured to provide the amount of fresh air required to the space at each of the three IA fan speeds Table 16 Default OA Damper Minimum Positions w o CO2 w CO2 IAF High Speed 20 5 IAF Medium Speed 30 5 IAF Low Speed 35 5 NOTICE If the CO2 Demand Controlled Ventilation DCV option is used then the UVC wi...

Page 24: ... The minimum damper position used with CO2 DCV can typically be set at 20 of the minimum position that would be used without CO2 DCV this number should then provide enough ventilation to keep odors within the space in check for most applications The CO2 DCV function can increase the OA damper position past that required by the economizer and vice versa If odors within the space become a problem in...

Page 25: ... will begin The UVC is configured such that whenever a floating point actuator is commanded to go to 0 or 100 the UVC will overdrive the actuator one full stroke period past the 0 or 100 position to ensure proper positioning Additionally theUVCisconfiguredtosyncallfloating pointactuators once every 12 hours of operation To do this the UVC will force the actuator to the nearest rail position 0 or 1...

Page 26: ... which are intended to be used with signal level voltages 24vac max only For wiring see MicroTech II Unit Ventilator Controller IM747 Not all of the functions listed can be used at the same time The UVC is provided with configuration parameters which can be adjusted to select which function will be used for these outputs when multiple functions are indicated below NOTICE EXTERNAL BINARY OUTPUT 1 T...

Page 27: ...ill perform the appropriate control actions Manual reset faults can be reset in one of three ways 1 cycle unit power 2 LUI menu or 3 via network interface AI 2 Remote Setpt Adjust Pot AI 3 DA Temp Sensor AI 4 OA Temp Sensor AI 5 IA Coil DX Temp Sensor AI 6 OA Coil DX Temp Sensor햷 Expansion Board xBO 1 External Output Option 2 Lights On Off햳 xBO 2 External Output Option 1 Exhaust Fan On Off햳 xBO 3 ...

Page 28: ...d if in cooling Outdoor fan if present is de energized Fault is indicated SPACE COIL DX TEMP SENSOR FAILURE The Space Coil DX Temp Sensor Failure fault will occur when the UVC detects an open or a short condition from the DX temperature sensor Effect Compressor is immediately de energized Outdoor fan if present is de energized Fault is indicated OUTDOOR TEMP SENSOR FAILURE The Outdoor Temp Sensor ...

Page 29: ... is calibrated according to the table shown Caution The humidity sensor is not protected against reversed polarity Check carefully when connecting the device or damage will result CAUTION Thefollowingprocedurecanbeusedtotroubleshootasuspecthumidity sensor 1 Disconnect the sensor s output voltage lead from the UVC analog input 2 Take a humidity reading at the sensor location 3 Use the humidity read...

Page 30: ...n when the exhaust interlock input is 100 open energized Energize Exhaust Fan OAD Setpoint OADE defines position above which exhaust fan output will be energized 10 open OAD Max Position Setpoint OAMX 100 open OAD Lockout Enable 0 disable 1 enable this variable will be factory set to 1 when the 0 unit is ordered as a recirc unit with no OAD OA temperature below which the OA damper will remain clos...

Page 31: ...or Cooling Lockout Setpoint CCLO OA temperature below which compressor cooling is not allowed 61O F 16O C Compressor Envelope Cool Max In 68O F 20O C Compressor Envelope Cool Min In 28O F 2 2O C Compressor Envelope Cool Max Out 150O F 65 6O C Compressor Envelope Cool Min Out 50O F 10 0O C Compressor Envelope Cool Max Ratio 0 56 Compressor Envelope Cool Max Offset 30O F 1 16O C Compressor Envelope ...

Page 32: ...50 2002 McQuay International www mcquay com 800 432 1342 OM 750 8 02 This document contains the most current product information as of this printing For the most up to date product information please go to www mcquay com ...