H705 Economizer Module - Honeywell Design and Application Technical Reference Manual

Section 4 - H705 Economizer Module
EXHAUST
AIR
OUTSIDE
AIR SENSOR
TR TR1
B C
SO
A D
SR
1
3
6
MINIMUM POSITION
CONTROL. PREVENTS
FULL CLOSURE OF
OUTSIDE AIR DAMPERS
The H705 was the first Honeywell series of
electronic economizer controllers. Prior to the
development of the H705, an
electromechanical device with a nylon
humidity element, the H205, was the state-of-
63-8594-02 Honeywell Economizers

H705 Economizer Module

H705 ENTHALPY CONTROL
DAMPER
DAMPER
+
+
5
2
4
X
D
10 0
80
12 0
60
40 14 0
°F
ROOM SENSOR
COILS
SUPPLY OR
MIXED AIR
DAMPER
SENSOR
ACTUATOR
the-art controller. The H705 was a direct
replacement for the H205. The output is the
same SPDT switch which is typically wired into
the mixed air circuit.
42
RETURN AIR
FROM ROOM
SUPPLY
AIR TO
BUILDING
FAN
2 HEAT 1
3 HEAT 3 COOL
2 HEAT 1
MOD-HEAT MOD-COOL
WH BH RH RC BC WC
SENSOR STAT 24 VAC ECONO
C +20 H H
3 4 2 5 1 TR TR W B Y R
T T1
SINGLEZONE CONTROL
COOL SETPOINT 76˚F (24 C)
M23914A