Honeywell AUTOMATIC CONTROL SI Edition User Manual

ENGINEERING MANUAL OF AUTOMATIC CONTROL
AIR HANDLING SYSTEM CONTROL APPLICATIONS
233
YEAR-ROUND HEAT RECOVERY PREHEAT SYSTEM CONTROL
Functional Description
Item
No. Function
1,2 Fans start and enable pump control upon
HVAC demand for ventilation (See FAN
SYSTEM START-STOP CONTROL).
3,4 Dampers close upon fan shutdown.
5 Pump runs when temperature conditions are
suitable for beneficial results.
6,10 The OA and RA temperature difference
determines when pump operation is beneficial.
7 Mixing valve prevents too much RA heat from
being transferred such that the SA temperature
exceeds that demanded by the HVAC control
system. Mixing valve also keeps water
entering the exhaust coil from dropping below
freezing to prevent the coil from frosting.
8,9 HVAC system SA temperature setpoint
determines valve position in winter.
11 Operator information.
12 Dynamic graphic sequence display permits
the operator to adjust program setpoints.
100
OA
SA
RA
EA
ON
ON
ON
N.C.
PERCENT OPEN
TO SUPPLY COIL
N.C.
N.C.
N.O.
C
SUPPLY
COIL
SETPOINT
SUPPLY FAN
HEATING SETPOINT DETERMINED
BY SUPPLY SYSTEM CONTROLS.
M15167
1
2
8
9
3
10
5
6
7
4
11
12
OPEN
OPEN
26
30
28
13
24
28
EXHAUST
COIL
PUMP
PUMP START SETPOINTS:
COOLING SETPOINT = ANYTIME OA
TEMPERATURE IS DEGREES
ABOVE RA TEMPERATURE.
HEATING SETPOINT = ANYTIME OA
TEMPERATURE IS DEGREES
BELOW SA TEMPERATURE SETPOINT
DETERMINED BY SUPPLY
SYSTEM CONTROL.
1.5
3.0

Honeywell AUTOMATIC CONTROL SI Edition Specifications

General

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