Honeywell AUTOMATIC CONTROL SI Edition User Manual

ENGINEERING MANUAL OF AUTOMATIC CONTROL
AIR HANDLING SYSTEM CONTROL APPLICATIONS
218
6. Line 3 represents the dry bulb value, to the right of which
the cooling coil could not handle the sensible load, no
matter how dry the air is. This is the high temperature
economizer cutout line used with the enthalpy and OA/
RA enthalpy comparison economizer decision.
19.5
OA
MA
RA
EA
1
22
ECONOMIZER MODE SELECTOR
OA MINIMUM SETPOINT
(NOTE: THE TEST AND
BALANCE INITIAL
VALUE FOR PROPER
VENTILATION IS 22)
OTHER INPUTS
AND OUTPUTS
ENTHALPY
kJ PER KILOGRAM
ENTHALPY
kJ PER KILOGRAM
M15156
7
9
11
3
8
6
83
10
1 2
83
CONTROL
PROGRAM
1 = AUTO BASED UPON OA/RA
ENTHALPY COMPARISON.
22.0
2 = AUTO BASED UPON OA DB
BELOW DEGREES
3 = MANUAL, ECONOMIZER ON.
4 = MANUAL, ECONOMIZER OFF.
NOTE: THE SYSTEM IS LOCKED OUT OF THE ECONOMIZER
MODE ANYTIME THE OA DRY BULB IS
ABOVE DEGREES.
9
52
49.0
4 5
26
45
27.5
OA DB
CONTROLLER
SELECTS OA
OA DB
CONTROLLER
SELECTS RA
ENTHALPY
CHANGEOVER
LINE, 50 kJ/kg
24°C DB, 54% RH
HIGH OA DB
CUT-OUT
3
1
4
5
2
6
7
C3258
ENTHALPY
CONTROL
SELECTS RA
ENTHALPY
CONTROL
SELECTS OA
ECONOMIZER CYCLE DECISION—OUTDOOR AIR/RETURN AIR
ENTHALPY COMPARISON
Functional Description

Honeywell AUTOMATIC CONTROL SI Edition Specifications

General

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