CBV-2U4-3T(-N) |
Control Sequence Overview
©ABB 2022 All Rights Reserved.
Subject to change without notice
WWW.CYLON.COM
42
M
AN0
13
9
re
v
14
4
Control Sequence Overview
This section provides an overview of the control features applicable to many of the
CBV-2U4-3T(-N)
control
sequences. The sections that follow go into more depth on each subject.
OCCUPANCY STATES AND MODE COMMANDS
Occupied State
The default state of the controller is occupied. If set in this mode, the
CBV-2U4-3T(-N)
will control to the
occupied temperature setpoints.
Unoccupied State
When indexed to the unoccupied state, the
CBV-2U4-3T(-N)
controllers will operate in a night setback mode
and control to the unoccupied setpoints.
Warm-up/Heating State
When units are commanded into the warm-up mode (primary air state is hot), after 60 minutes, each
CBV-
2U4-3T(-N)
controller will operate its associated box heat and any perimeter heat as required to return the
zone to the occupied heating temperature setpoint.
Standby State of Operation
After the warm-up state is complete, the master controller may (optionally) set each terminal unit to the
standby state. This state may be utilized to maintain a zone ready for occupancy with minimum energy
utilization.
Primary Air State Command
The primary air state command tells the
CBV-2U4-3T(-N)
to expect hot or cold air. While in the off condition
primary air state is cold.
Primary Air Mode
Primary Air Mode is either ON or OFF indicating the AHU fan status or command state. The unit will only operate
when Primary Air Mode is set OFF
TEMPERATURE CONTROL
Control Modes
The
CBV-2U4-3T(-N)
continuously compares the zone temperature with the active setpoints. Heating demand
and cooling demand calculations are constantly updated. These calculations are expressed as 0
…
100% heating
needed and 0
…
100% cooling needed.
•
Heating Mode
In the heating mode, stages of heat are energized, and/or valve positions are increased, as the heating demand
increases. Primary supply air Flowrate is set to the current primary air heating flow setpoint. If the terminal
unit includes a variable speed fan, its speed will increase with heating demand.
•
Cooling Mode
In the cooling mode, the primary air Flowrate setpoint is modulated toward maximum as the cooling demand
increases. If the terminal unit includes a series variable speed fan, its speed will increase with cooling demand.
•
Deadband Mode
In the deadband mode, the primary air Flowrate setpoint is reduced to minimum. All heating is off, parallel fans
are off, and series variable speed fans are set to minimum.
Summary of Contents for CBV-2U4-3T
Page 1: ... USER GUIDE MAN0139 rev 14 CBV 2U4 3T N ...
Page 75: ......