Ucm Control System - Trane IntelliPak I Programming, Troubleshooting Manual

Return Plenum Pressure High Limit. This control feature, available on all return fan
options, shuts the supply fan and return fan off if the pressure in the return plenum
exceeds a non-adjustable SETPOINT of 3.5 iwc.
Space Pressure. The pressure in the building as measured by the Space Pressure
Transducer, referenced to outside (atmospheric) pressure.
Supply Air Pressure High Limit. A pressure limit to prevent unit casing and/or ductwork
over pressurization.
Statitrac™. A trademark for control of space pressurization.
Supply Air Pressure. The pressure in inches water column (IWC) of the supply duct
plenum or outlet as measured by the Supply Air Pressure Transducer, referenced to
local outside (atmospheric) pressure.
Supply Air Tempering. Turning on heat when the supply air temperature drops below a
preset value usually due to cold outside air being brought in to provide building
ventilation.
Supply Air Temperature Control Point. The revised value of supply air temperature
SETPOINT after supply air temp reset has been applied.
Supply Air Temperature Reset. A function that shifts the SA Temp SETPOINT an
amount based on the value of another parameter—typically Zone Temp or Outdoor Air
Temp. The purpose of this function is to lower unit capacity to better meet load
requirements.
Target. Dynamic control point the unit is controlling to at any given time.

UCM Control System

Trane Large Commercial Rooftop Units are controlled by a microelectronic control
system that consists of a network of modules and are referred to as Unit Control
Modules (UCM).
The unit size, type (CV or VAV), heating functions, peripheral devices, options, exhaust
capabilities, etc. determine the number and type of modules that a particular rooftop
unit may employ.
The UCM receives analog and binary inputs, then processes this information and
supplies outputs in the form of modulating voltages, contact closures, etc. to control
damper actuators, fan motors, compressors, valves, electric heating coils and other
electrical devices in the unit to maintain set comfort levels.
The UCM provides some equipment protection functions both directly and indirectly,
such as duct pressure limits and compressor lockouts.
Listed below are the various modules that may be employed in a UCM control system.
RT-SVP04F-EN
General Information
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