Honeywell AUTOMATIC CONTROL SI Edition User Manual

ENGINEERING MANUAL OF AUTOMATIC CONTROL
AIR HANDLING SYSTEM CONTROL APPLICATIONS
248
YEAR-ROUND SYSTEM CONTROL PROCESSES
HEATING, COOLING, AND ECONOMIZER
Functional Description
Item
No. Function
1-3 Control system energizes when fan is turned
on (See FAN SYSTEM START-STOP
CONTROL).
4-6 Mixing dampers modulate to maintain
minimum ventilation value and free cooling
SA temperature setpoint.
7 Economizer enables free cooling when OA is
appropriate.
8 Space temperature dictates heat and cool
demands.
9-13 Free cooling setpoint and heat/cool dead-
band values determine the SA temperature
setpoint for hot and chilled water control
setpoints. Software has a minimum 0.8
kelvins heating and cooling deadband.
14 Heat demand varies SA temperature setpoint.
M15176
OA
EA
RA
SA
3
2
ON
ON
1
100
5
100
1619
4
20
NORMAL
ECONOMIZER DECISION.
REFER TO PREVIOUS
ECONOMIZER OPTIONS
OA MINIMUM SETPOINT
(NOTE: THE TEST AND BALANCE
INITIAL VALUE FOR PROPER
VENTILATION IS 22)
7
6
22
CONTROL
PROGRAM
22
96
17
14
18
41
13
SUPPLY AIR
TEMPERATURE
SETPOINT
SPACE
HEATING
DEMAND
100
0
24
13
SUPPLY AIR
TEMPERATURE
SETPOINT
CHW
COOLING
DEMAND
0
100
24
14
SUPPLY AIR
TEMPERATURE
SETPOINT
FREE
COOLING
DEMAND
0
100
18
21
036
SUPPLY
FAN
PERCENT
OPEN
NC
NO
NC
SPACE TEMPERATURE
15
15
18
11
9
10
23.5
24.5
1.1
8
24.5
SETPOINT
13
22
SETPOINT
100
0
CHILLED WATER COOLING
SETPOINT = FREE COOLING
SETPOINT PLUS
FREE COOLING
SETPOINT
(0.8 MINIMUM)
12
1.1
HEATING SETPOINT = FREE
COOLING SETPOINT MINUS
(0.8 MINIMUM)

Honeywell AUTOMATIC CONTROL SI Edition Specifications

General

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