Specifications

FIGURE 15 – Steam Humidifier Wiring and Utility Diagram with Blower Control by Humidifier
90-929
INPUT POWER
with Ground.
Refer to wiring
diagram.
STEAM
OUTLET
FIELD
WIRING
TERMINAL
BLOCK
Aprilaire Model 1150/1160/1180
Steam Humidifier
DRAIN WATER OUT
¾" COPPER or 1" HOSE
SUPPLY WATER IN
¼" COMPRESSION FITTING
Field Wiring Terminal Block Designations
Command Signal
Enable Input
+24 VDC
Normally Closed, Common, &
Normally Open relay terminals
for optional blower control by
humidifier or remote fault alarm
1
2
30
NC
O
NO
High Voltage Wiring
Low Voltage Wiring
Steam
Fill
Drain
On/Off
3 wire shielded cable
with ground shield
connected to C
2 wire shielded
cable with
ground shield
connected to C
1
2 30 NC O NO C
L1
L2 GND
1+
1-
24V
C
H+ H-
ODT
To Outdoor
Temperature
Sensor
High Humidity
Limit Switch
Airflow Proving
Switch
Automatic Steam
Humidifier Control
Terminal Designations
1+, 1- Serial Communications
(for optional devices)
H+ Command Signal to
Humidifier
H- Command Signal to
Ground (not used)
Connect ¼" plastic
tubing from H (High)
side of proving switch
to the airflow sensing
probe located 1.5 duct
diameters downstream
of blower. Leave L
(Low) side open to
atmosphere.
Switch breaks C to
NC connection when
measured RH is above
setpoint RH
NCNOC
NC
NO
C
HVAC Equipment
Thermostat
Connections required for Blower Control by Steam Humidifier
R
C
W Y G
R C W YG
21