9
8
Figure D – Fiber Board Duct Mount
90-1203
CONTROL BOARD
COVER
KNOB
BASE PLATE
RETURN DUCT
RETURN
DUCT
SHEET METAL
PLATE
CUT OPENING IN
RETURN DUCT
SHEET METAL PLATE
GASKET
SCREW (x2)
INSIDE OF
RETURN
DUCT
Figure E – Digital Humidifier Control 24V Terminals
90-1397
H
W/G Cf
ODT
B
A
C
R
OUTDOOR
TEMPERATURE
SENSOR OR
MANUAL MODE
RESISTOR
CONTINUOUS 24V
POWER FOR CONTROL
FOR
COMMUNICATION
WITH APRILAIRE
8570 THERMOSTAT
24V BLOWER
OPERATION SIGNAL
FROM HVAC
EQUIPMENT
24V SIGNAL TO
HUMIDIFIER
