Honeywell AUTOMATIC CONTROL SI Edition User Manual

ENGINEERING MANUAL OF AUTOMATIC CONTROL
AIR HANDLING SYSTEM CONTROL APPLICATIONS
250
MULTIZONE UNIT
Functional Description
Item
No. Function
1,2 Control system energizes when fan is turned
on (See FAN SYSTEM START-STOP
CONTROL).
3,4 Mixing dampers position to minimum
position during occupied fan operation and
modulate for cooling.
5-8 Zone mixing dampers modulate to maintain
space temperature setpoint.
9 Zone with greatest cooling demand
determines cold deck temperature setpoint,
and zone with greatest heating demand
determines hot deck temperature setpoint.
10,11 Hot deck valve modulated to maintain hot
deck temperature setpoint.
12,13 Cold deck valve modulated to maintain cold
deck temperature setpoint.
14 Economizer enables free cooling when OA is
suitable.
15 Fan leaving air temperature for operator
information.
16 Control program coordinates cooling, heating,
ventilation, and fan interlock control.
M15178
OA
RA
SA
2
ON
1
22
78
14
4
3
NORMAL
ECONOMIZER DECISION.
REFER TO PREVIOUS
ECONOMIZER OPTIONS
OA MINIMUM SETPOINT
(NOTE: THE TEST AND
BALANCE INITIAL
VALUE FOR PROPER
VENTILATION IS 22)
CONTROL
PROGRAM
22
13
8
11
16
12
15
14
25
PERCENT
OPEN
10
25
00
00
23.5
46
23.5
SETPOINT
SPACE
TEMPERATURE
PERCENT
OPEN TO
COLD
DECK
HALL
LOBBY
23.5
62
23.5
23.5
100
24.5
EAST
OFFICE
WEST
OFFICE
5 76
THE ZONE WITH THE GREATEST HEATING DEMAND
RESETS THE HOT DECK TEMPERATURE FROM
TO DEGREES AS REQUIRED TO
MAINTAIN ITS SPACE TEMPERATURE
DEGREES BELOW SETPOINT.
THE ZONE WITH THE GREATEST COOLING DEMAND
RESETS THE COLD DECK TEMPERATURE FROM
TO DEGREES AS REQUIRED TO
MAINTAIN ITS SPACE TEMPERATURE
DEGREES ABOVE SETPOINT.
1.0
1.0
26
13
15
36

Honeywell AUTOMATIC CONTROL SI Edition Specifications

General

Brand	Honeywell
Model	AUTOMATIC CONTROL SI Edition
Category	Control Systems
Language	English