Honeywell AUTOMATIC CONTROL, Engineering Manual

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ENGINEERING CMANUAL OF AUTOMATION CONTROL
AIR HANDLING SYSTEM CONTROL APPLICATIONS
241
SA
MA
ON
76
46
COLD
DECK
ZONE
MIXING
DAMPERS
AS THE DEMAND FOR COOLING FROM THE ZONE
VARIES BETWEEN ZERO AND %, ITS COLD
DECK DAMPERS MODULATE BETWEEN CLOSED AND OPEN.
AS THE DEMAND FOR COOLING FROM THE ZONE WITH THE
GREATEST DEMAND FOR COOLING VARIES BETWEEN
AND 100%, THE COLD DECK TEMPERATURE
SETPOINT VARIES BETWEEN THE MIXED AIR
TEMPERATURE AND DEGREES.
76
SETPOINT
SPACE
TEMPERATURE
PERCENT
OPEN
HALL
LOBBY
M10475
1
76
46
76
76
66
55
46
76
EAST
OFFICE
WEST
OFFICE
8
5
7
9
6
4
3
2
CONTROL
PROGRAM
78
50
50
55
COLD DECK SYSTEM WITH ZONE DAMPER CONTROL
Functional Description
Item
No. Function
1 Control system energizes when fan is turned
on
(
See FAN SYSTEM START-STOP
CONTROL
).
2-4 Zone mixing dampers modulate to maintain
space temperature setpoint.
5,6 Chilled water valve modulates to maintain
cold deck temperature setpoint.
7 Mixed air temperature determines cold deck
temperature setpoint at zero cooling load.
8 Control program coordinates zone demand,
temperature, and fan interlock control.
9 Dynamic graphic sequence display permits
the operator to adjust program setpoints.
FEATURES
1. A mixing damper and temperature sensor for each zone
provides individual zone control. (Three zones shown).
2. A single cooling coil or group of coils furnishes cooling
for the entire system.
3. A constant volume of air is delivered to each zone.
4. Cold deck temperature is maintained just low enough to
satisfy the zone requiring the greatest amount of cooling
which provides efficient operation when used in conjunction
with a hot deck coil/control multizone system.