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22

McQuay OM 751

Description of Operation

In each of these special purpose UVC modes, if the space temperature drops below EHS and 
the Emergency Heat function is enabled, the UVC is forced into the Emergency Heat mode 
(see “Emergency Heat Mode (Super State)” on page 16) and then return once the Emergency 
Heat function is satisfied.

Table 9: Actions during special purpose unit modes

Pressurize Mode

When in Pressurize mode, the UVC uses the IAF, OAD, and exhaust output as needed to 
pressurize the space. The UVC stops all normal heating and cooling but does allow emergency 
heat if required. The pressurize mode can only be accessed via a network connection.

Depressurize Mode

When in Depressurize mode the UVC will use the IAF, OAD, and exhaust output as needed to 
depressurize the space. The UVC stops all normal heating and cooling but does allow 
emergency heat if required. The de-pressurize mode can only be accessed via a network 
connection or with ServiceTools for MicroTech II Applied Terminal Unit Controllers (ATS).

Purge Mode

When in Purge mode, the UVC uses the IAF, OAD, and exhaust output as needed to purge the 
space. The UVC stops all normal heating and cooling but does allow emergency heat if 
required. The purge mode can only be accessed via a network connection or with ServiceTools 
for MicroTech II Applied Terminal Unit Controllers (ATS).

Shutdown Mode

Shutdown mode is the equivalent of the Off mode, but is an Off mode forced by a network 
connection. When in Shutdown mode, the UVC stops all normal heating, cooling, ventilation 
(OA damper is closed), and fan operation. By default emergency heat is not be used during the 
shutdown mode, however, the UVC can be configured (Emergency Heat Shutdown 
Configuration) to allow emergency heat operation during shutdown mode. The shutdown 
mode can be accessed via a network connection, a binary input to the UVC, or with 
ServiceTools for MicroTech II Applied Terminal Unit Controllers (ATS).

Energy Hold Off Mode

The UVC supports an energy hold off state, which when active forces the UVC to stop all 
normal heating, cooling and ventilation. Typically used by a network connection to force the 
UVC to cease heating, cooling and ventilation when conditions exist where heating, cooling 
and ventilation are not required or desired. Energy hold off mode is very similar to shutdown 
mode except that energy hold off always allows emergency heat if required. The energy hold 
off mode can only be accessed via a network connection or with ServiceTools for
MicroTech II Applied Terminal Unit Controllers (ATS).

Action

Indoor air fan 

(IAF)

Outdoor air 

damper (OAD)

Exhaust fan 

output

Pressurize

High

100% Open

Off

Depressurize

Off

Closed

On

Purge

High

100% Open

On

Shutdown

Off

Closed

Off

Energy hold off

Off

Closed

Off

WARNING

Shutdown mode and energy hold off mode are a “stop” state for 
the unit ventilator. It is not a “power off” state. 

Содержание UV05

Страница 1: ...ntilators Operation Maintenance Manual OM 751 1 Group Applied Systems Part Number OM 751 Date November 2006 IMPORTANT Before unit commissioning please read this publication in its entirety Develop a t...

Страница 2: ...n 32 Cycle Fan 32 Off Delay 32 Outdoor Air Damper Operation 32 Minimum Position 32 Economizer Operation 32 Networked Space Humidity Sensor Capability 34 Networked Outdoor Humidity Sensor Capability 34...

Страница 3: ...ported network variables for each protocol refer to Protocol Data Packet bulletin ED 15065 Table 1 Model specific unit ventilator installation literature Table 2 Protocol specific communication card i...

Страница 4: ...nd if not installed and used in accordance with this instruction manual may cause interference to radio communications It has been tested and found to comply with the limits for a Class A digital devi...

Страница 5: ...Enthalpy Differential EED Economizer OA Enthalpy Setpoint EES Emergency Heat Setpoint EHS Exhaust Interlock OAD Min Position Setpoint EOAD Outdoor Air Temperature Setpoint EOAT End of Cycle EOC EOC OA...

Страница 6: ...O Read Write RW Standby Cooling Setpoint SCS Standby Heating Setpoint SHS Thermal Expansion Valve TXV Unoccupied Cooling Setpoint UCS Unoccupied Heating Setpoint UHS Unit Ventilator UV Unit Ventilator...

Страница 7: ...fective heating or cooling temperature set point Effective Set Point Output The display also is used to view and modify UVC parameters as explained in the following sections Note When the UVC is in th...

Страница 8: ...each of the fan speeds Fan Speed Command Input Auto Low Medium and High MODE Key Use the MODE key to toggle through the keypad display accessible unit modes Heat Cool Mode Input Auto Heat Cool and Fan...

Страница 9: ...and ignore the remote wall sensor set point adjustment knob To use the remote wall sensor set point adjustment knob after you changed the set point offset on the keypad display clear the keypad displa...

Страница 10: ...rride Input Set occupancy 0 occupied 1 unoccupied 2 bypass 3 standby Adjusting this variable is intended only for troubleshooting Once you are done cycle unit power to clear this variable and return t...

Страница 11: ...ential AHSD Adjust auxiliary heat start differential RW x 1 8 F 1 C A2 Auxiliary Heat End Differential AHED Adjust auxiliary heat stop differential RW x 1 8 F 1 C A3 Auxiliary Heat Configuration Set a...

Страница 12: ...into a single control function such as cooling or heating etc States are where all the actual work takes place within each state the UVC enables PI loops and other logic sequences required to control...

Страница 13: ...states depending upon the functionality required for each particular mode Each UVC state is assigned a number which can be very helpful when trying to understand which state is currently active within...

Страница 14: ...in the OFF mode the UVC is forced into the Emergency Heat mode see Emergency Heat Mode Super State on page 16 The space lighting output continues to operate based upon the current occupancy mode Note...

Страница 15: ...External Binary Outputs on page 38 is set to ON If the UVC is not set to another mode within 1 hour fixed the UVC automatically switches to the Fan Only mode see Fan Only Mode State A on page 15 While...

Страница 16: ...EHS When Emergency Heat mode becomes active the UVC goes into 100 heating until the space temperature raises to the EHS plus a fixed differential 5 4 F 3 C In the Emergency Heat mode the space fan is...

Страница 17: ...diagram Heat State State 5 The Heat state is the normal state during Heat mode When the Heat state becomes active the UVC will within State continually calculate the DATS Discharge Air Temperature Con...

Страница 18: ...e 29 Cant Heat State State B The Cant Heat state is a non normal state the UVC can go to when Heat mode is active An IAT or DAT sensor fault during the Heat mode causes the UVC to make this state acti...

Страница 19: ...VCLL The CO2 demand controlled ventilation function optional will be active see CO2 Demand Controlled Ventilation optional on page 34 and the OA damper is adjusted as needed to maintain the CO2 set po...

Страница 20: ...erature Set Points on page 26 The UVC monitors the DAT to ensure it does not fall below MCLL Figure 14 Econ mech state operation occupied mode and auto fan Mech State State 2 The Mech state is a norma...

Страница 21: ...ntain the CO2 set point Low Limit State State F The Low Limit state is a non normal state during Cool mode The Low Limit state typically follows the DA Heat state when the UVC reaches 100 heat and sti...

Страница 22: ...Controllers ATS Shutdown Mode Shutdown mode is the equivalent of the Off mode but is an Off mode forced by a network connection When in Shutdown mode the UVC stops all normal heating cooling ventilat...

Страница 23: ...rmal UVC mode priority Table 11 Energy hold off Energy hold off Off Off Energized5 Don t care Energy hold off Off Off Pressurize Don t care Don t care Don t care Off Pressurize De pressurize Don t car...

Страница 24: ...rmal day time mode of UVC operation During occupied mode the UVC uses the occupied heating and cooling set points the OAD operates normally and by default the IAF remains on Unoccupied Mode The unoccu...

Страница 25: ...the tenant override feature For example if the network uses the Occupancy Override Input to force the unit into unoccupied mode then the unit mounted tenant override switch does not operate as expecte...

Страница 26: ...aving a relative set point knob Use the keypad display to make adjustments to the value of the Setpoint Offset Input variable See Changing Set Points on page 9 Note The keypad display and the network...

Страница 27: ...adjustment dial is used the UVC will effectively write the value of the set point dial to the Space Temp Set Point Input variable Note If a network connection is using the Space Temp Set Point Input v...

Страница 28: ...t Occupied Cooling Set Point OCS Standby Cooling Set Point SCS Unoccupied Cooling Set Point UCS Occupied Heating Set Point OHS Standby Heating Set Point SHS Unoccupied Heating Set Point UHS Occupied C...

Страница 29: ...charge Air Temperature Setpoint Output Figure 18 Cascading PI loop graphic 1 primary heat Figure 19 Cascading PI loop graphic 2 primary cool economizer PI loops PI loop type Set point Feedback control...

Страница 30: ...r Figure 20 Optimized PI loop control Proportional Band The proportional band or proportional action causes the controlled output to changes in proportion to the magnitude of the difference between th...

Страница 31: ...small long oscillations occur see Figure 22 In general it is best to start with a relatively large integral time setting the factory default setting is best and adjust to smaller values If you want th...

Страница 32: ...occupancy modes and closed during the unoccupied and standby occupancy modes A Triac output is best tested under load using a 24 V relay for verification To verify 1 Put a relay across the Triac outpu...

Страница 33: ...enthalpy In this case the UVC is factory set for Economizer Strategy 2 and uses the Temperature Comparison with Enthalpy Comparison Economizer function Note Temperature Comparison with Enthalpy Compar...

Страница 34: ...in treating OA not actually needed for ventilation within a space during occupancy levels below maximum design The CO2 DCV function uses a PI loop control to adjust the OA damper above the minimum po...

Страница 35: ...or Envelope The compressor envelope protects the compressor from adverse operating conditions that can cause damage and or shortened compressor life by ending compressor operation if coil temperatures...

Страница 36: ...The OA fan stops with the compressor Floating Point Actuator Auto Zero Overdrive and Sync The UVC at power up auto zeros all floating point actuators OA damper before going into normal operation to en...

Страница 37: ...into unoccupied mode When the contacts open the UVC goes into occupied mode Additional variables can effect occupancy mode and override this binary input See Occupancy Modes on page 24 External Binary...

Страница 38: ...ters that can be adjusted to select which function will be used for these outputs when multiple functions are indicated below External Binary Output 1 This output can only be used as a signal for spac...

Страница 39: ...an auxiliary heat device The UVC by default is configured to operate a Normally Open auxiliary heat device de energize when heat is required such as a wet heat valve actuator with a spring setup to op...

Страница 40: ...or Exhaust Interlock3 3 Field selectable external input options all possible options are shown BI 5 External Input Option 2 Remote Shutdown3 BI 6 External Input Option 1 Unoccupied default BI 7 BI 8 B...

Страница 41: ...ibed for each fault Manual reset faults can be reset in one of three ways By cycling the unit power Via the keypad display menu Via the network interface Table 22 Alarm and fault code summary Priority...

Страница 42: ...nvelope Fault occurs when the UVC detects compressor operation that exceeded the allowed operating parameters Effect Compressor immediately de energizes Outdoor fan if present de energizes Fault is in...

Страница 43: ...e UVC detects open or short conditions from the sensor Effect Outside air damper is forced closed Compressor immediately de energizes Fault is indicated Discharge Air Temp Sensor Failure F7 The Discha...

Страница 44: ...fault occurs when the UVC calculates that the total fan run time has exceeded the allowed number of hours since the last filter change Effect Fault is indicated EPROM Memory Indicator EE The EPROM Mem...

Страница 45: ...y reading at the sensor location 3 Use the humidity reading from Step 2 determine the expected sensor voltage from Table 24 4 Using a calibrated multi meter measure the actual voltage across the yello...

Страница 46: ...4 Using a calibrated multi meter measure the actual voltage across the lead removed from xAI 3 and ground 5 Compare the expected voltage to the actual voltage 6 If the actual voltage value deviates su...

Страница 47: ...tpoint OADH this variable will be factory set to 5 open when the unit is ordered with optional CO2 DCV 20 open o2 OAD Min Position Med Speed Setpoint OADM this variable is ignored when the unit is ord...

Страница 48: ...t 0 Compressor Enable 0 disable 1 enable 1 C Compressor Minimum On Time 180 sec Compressor Minimum Off Time 300 sec Compressor Cooling Lockout Setpoint CCLO OA temperature below which compressor cooli...

Страница 49: ...ems use 327 67 for self contained units 327 67 invalid 327 76 Application Name and Version Label Compressor Start Delay adjust the compressor delay used to prevent multiple compressor units from start...

Страница 50: ...training or call 540 248 9646 and ask for the Training Department Warranty All McQuay equipment is sold pursuant to its standard terms and conditions of sale including Limited Product Warranty Consul...

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