24V OUTPUT FROM HUMIDIFIER (RED WIRES) OR
727-58 24 V. TRANSFORMER WITH CONSTANT POWER
OR 24 VAC POWER SUPPLY WITH CONSTANT POWER
HUMIDIFIER CONTROL LEADS
(YELLOW WIRES)
OUTDOOR TEMP. SENSOR
(NOT USED IN MANUAL MODE)
AC L
AC N
HUM
SNSR
INSTRUCTIONS FOR WIRING HUMIDIFIER
NOTE: ALL WIRING SHOULD COMPLY WITH LOCAL ELECTRICAL
CODES.
6A WITH FURNACE CIRCUIT BOARD
Use with mechanical humidistat only. On furnaces with output terminals
ACC, or EAC check output voltage to determine that terminals are 115V.
Connect on-off switch in series with the hot wire. Install humidistat and
connect to yellow wires on humidifier.
6B WITH CONSTANT POWER TO HUMIDIFIER
Use with mechanical humidistat only. Mount a junction box and 115v.
grounded outlet. Connect the on-off switch in series with the hot or black
wire. Install a field supplied 24 volt relay and attach to HUM and C on the
furnace control board. Install humidistat and connect one side to one
yellow wire on humidifier. Connect the other side of the humidistat to one
end of switch side of the relay. Connect the other switch side of the the
relay to the remaining yellow wire on humidifier.
Red humidifier leads
are not used for this wiring method. Do not touch red wires together.
Damage to the humidifier will result.
6C WITH ELECTRONIC HUMIDISTAT - PRESSURE SENSING
On furnaces with a two speed blower, the humidifier and a Model 12500
Air Pressure Switch may be wired from a continuous 115 volt power
source. Install the on/off switch in series with hot or black wire and Air
Pressure Switch in series with the humidistat circuit. The Air Pressure
Switch will detect furnace operation and supply power to the humidifier
accordingly.
6D WITH ELECTRONIC HUMIDISTAT - CURRENT SENSING
On furnaces with a two speed blower, the humidifier may be wired from a
continuous 115 volt power source. Install the on/off switch in series with
the hot or black wire. Install the GA50 Current Sensing Relay in series
with the humidistat circuit. The Current Sensing Relay will detect furnace
operation and supply power to the humidifier accordingly.
7 7
5
GFX3 ELECTRONIC HUMIDISTAT
Turn on water supply and plug in power cord to check operation of
humidifier. Set humidistat to a demand setting. With the furnace off, the
solenoid valve should be closed and the humidifier fan not running. Start
the furnace, the solenoid valve should open and the humidifier fan run
when the blower or burner circuit is energized. Check flow of water
through distributor trough and evaporator pad. The standard GA4231
yellow orifice will supply approximately 3.5 GPH of water at a line water
pressure of 60 psi. For low water pressures (20-40 psi) a larger orifice
GA4299 is available to provide the same flow. Leave humidistat set at the
recommended setting.
8
AC L
AC N
HUM
SNSR
HUMIDIFIER CONTROL LEADS
(YELLOW WIRES)
ACC
EAC
(HOT)
C
115v.
60CY.
ON-OFF
SWITCH
6A
6C
6B
HUMIDIFIER
120v. OUTLET
COMMON LEAD
C
HI
LO
GA50 CURRENT
SENSING RELAY
MULTI
SPEED
BLOWER
MOTOR
6D
HUMIDIFIER
L1
(HOT)
L2
115v.
60CY.
ON-OFF
SWITCH
GRD
HUMIDIFIER
120v. OUTLET
GRD
6
12500 AIR
PRESSURE
SWITCH
NO
C
AC L
AC N
HUM
SNSR
HUMIDIFIER CONTROL LEADS
(YELLOW WIRES)
L1
(HOT)
L2
115v.
60CY.
ON-OFF
SWITCH
GRD
120v. OUTLET
HUMIDISTAT POWER LEADS
(RED WIRES 24 VAC)
HUMIDISTAT POWER LEADS
(RED WIRES 24 VAC)
(HOT)
C
115v.
60CY.
ON-OFF
SWITCH
HUMIDIFIER
120v. OUTLET
GRD
L1
YELLOW WIRES
FROM HUMIDIFIER
FURNACE
CONTROL BOARD
60CY.
24V.
C
HUM
FIELD SUPPLIED
RELAY 24V COIL, N.O.
HUMIDISTAT
MHX3 MANUAL HUMIDISTAT
Replace evaporator pad assembly and humidifier cover. Insert low voltage
six connector wiring harness from cover into chassis solenoid harness.
DUCT MOUNT PLATE
STANDARD FOR USA
OPTIONAL ACCESSORY FOR
CANANDA
WALL MOUNT PLATE
STANDARD FOR CANADA
OPTIONAL ACCESSORY FOR
USA
C
NO
NC