Sequence Of Operations; Chapter Overview; Calibration - Trane VAV VV550 LonTalk Installation & Operation Manual

Microprocessor-based, direct digital controller (ddc) for the (variable air volume) vav terminal unit
Table of Contents

Advertisement

Sequence of Operations

Chapter Overview

This chapter contains information about the following:
Normal Operation
The controller is functioning normally when it is operating in one of the three control modes (space
temperature control, ventilation control, or flow tracking control) and in one of four occupancy
modes (occupied mode, unoccupied mode, occupied standby mode, or occupied bypass mode).
Note: For More detail on control modes and units operation see CNT-SVX17*-EN.

Calibration

The calibration sequence enables the controller to calibrate the air valve position and the water
valve position. Calibration takes place if autocalibration is enabled and either a power cycle or a
transition from occupied to unoccupied has occurred.
Note: Whether or not autocalibration is enabled, the controller initiates calibration on a
The building automation system is responsible for the staggering of the calibration sequence that
is needed between units. When autocalibration is enabled and a transition from occupied to
unoccupied occurs, the calibration sequence starts after a fixed delay of three minutes. The
controller effective occupancy mode is unoccupied, but runs like it is occupied during this three
minute period. The mode field of reported unit status reports calibration when the controller is in
the calibration sequence. If autocalibration is disabled, the air valve and water valve are not driven
closed and the flow sensor zero flow voltage reading is not recorded. Refer to
calibration actions.
Table 10. Calibration actions
I/O Device
Air valve
Flow sensor
Modulating hot water reheat
Fan
Electric or On/Off hot water
VAV-SVP01A-EN
Calibration
Occupancy Modes
Space Temperature Control: Single Duct Units
Space Temperature Control: Fan-Powered Units
Ventilation Flow Control
Flow Tracking
communicated application mode command.
Calibration Action Taken
Drive the air valve closed to the stroke time plus 20 seconds
Record the flow reading when the air valve is fully closed
Drive the water valve closed for the stroke time plus 20 seconds
Enabled
Disabled
Table 10, p. 67
Result After Calibration
initialize the air valve position as closed when
the air valve is over-driven
Subtract the zero flow reading from all
subsequent readings
initialize the water valve position as closed when
the water valve is over-driven
Enabled
Enabled
for
67

Advertisement

Table of Contents
loading

Table of Contents