McQuay IM 743 Operation & Maintenance

OM 750 Page 3 of 32
Index of
Meaning of Abreviations
Abreviations
AHED Auxiliary Heat End Differential
AHSD Auxiliary Heat Start Differential
ASCII American Standard Code for Information Interchange
ASHRAE
American Society of Heating, Refrigerating,
and Air Conditioning Engineers, Inc
CCLO Compressor Cooling Lockout Setpoint
CO2S CO
2
Setpoint
CW Chilled Water
CWVP Chilled Water Valve Position
DA Discharge Air
DAHL Discharge Air High Limit
DAT Discharge Air Temp
DATS Discharge Air Temp Setpoint
DCV Demand Controlled Ventilation
ECD Economizer Compare Differential
EED Economizer Enthalpy Differential
EES Economizer Enthalpy Setpoint
EHS Emergency Heat Setpoint
EOAD Exhaust Outdoor Air Damper
EOAT Outdoor Air Temperature Output
EOC End-of-Cycle
EOCS End-of-Cycle Low OAT Setpoint
EORH Outdoor Air Humidity Output
ERH Space Humidity Output
ETD Economizer Temperature Differential
ETS Economizer Temperature Setpoint
EWIT Source (Water-in) Temperature
FBDP Face and Bypass Damper Position
FCC Federal Communications Commission
F & BP Face & Bypass
HVACR Heating, Ventilating, Air Conditioning, Refrigerating
HW Hot Water
IA Indoor Air
IAF Indoor Air Fan
IAT Indoor Air Temperature
UVC Input and Output Table .............................................. 27
Diagnostics and Service.................................................. 27
Alarm and Fault Monitoring ......................................................... 27
Space Temp Sensor Failure ................................................... 28
DX Pressure Fault .................................................................. 28
Compressor Envelope Fault ................................................... 28
Discharge Air DX Cooling Low Limit 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 Position High-Speed Setpoint
OADL OAD Min Position Low-Speed Setpoint
OADM OAD Min Position Medium-Speed Setpoint
OADP Outdoor Air Damper Position
OALS Outside Air Lockout Position
OAMX OAD Maximum Position Setpoint
OAT Outdoor Air Temperature
OCS Occupied Cooling Setpoint
OHS Occupied Heating Setpoint
PI Proportional Integral
PPM Parts Per Million
RH Relative Humidity
RHS Space Humidity Setpoint
RO Read Only
RW Read Write
SCS Standby Cooling Setpoint
SHS Standby Heating Setpoint
TXV Thermal eXpansion Value
UCS Unoccupied Cooling Setpoint
UHS Unoccupied Heating Setpoint
UV Unit Ventilator
UVC Unit Ventilator Controller
UVCM UVC (Heat/Cool) Mode Output
UVCS UVC State Output
VALP Wet Heat Valve Position
VCLL Ventilation Cooling Low Limit
WH Wet Heat
WITD Source (Water-in) Temperature Differential
Discharge Air Temp Sensor Failure........................................ 28
Outdoor Coil DX Temp Sensor Failure ................................... 28
Space Humidity Sensor Failure (optional) ............................. 28
Outdoor Humidity Sensor Failure (optional) .......................... 28
Space CO
2
Sensor Failure (optional) ...................................... 29
Change Filter Indication ......................................................... 29
Troubleshooting Temperature Sensors ........................................ 29
Troubleshooting Humidity Sensors ............................................. 29
Troubleshooting Carbon Dioxide (CO
2
) Sensors .......................... 29
UVC Configuration Parameters .......................................... 30

McQuay IM 743 Specifications

General

Brand	McQuay
Model	IM 743
Category	Controller
Language	English