58 Installation Instructions

FURNACE ACCESSORY
TERMINALS
TERMINALS MAY BE LABELED:
“HUM”, “ACC” OR “EAC”
24 VAC TRANSFORMER
H
DIGITAL HUMIDIFIER CONTROL TERMINAL STRIP
W/G CfODTBACR
“HUM”
COMMON
OUTDOOR TEMPERATURE
SENSOR OR MANUAL MODE
RESISTOR
1514
USING FURNACE ACCESSORY TERMINALS TO DETECT
FURNACE OR BLOWER OPERATION (FIGURE K)
See the furnace manual for voltage and operation of the
accessory terminals. If accessory terminals are 120 Volts, install
a 24 VAC transformer.
“HUM” for operating humidifier during heat call.
“EAC” for operating humidifier when HVAC blower is on.
or
“EAC” for operating humidifier with continuous fan setting
on thermostat.
NOTE: Plumb humidifier to hot water when using “EAC” terminals.
Figure K
90-1221
STEP 11: Power Source for Humidifier Control –
Terminals R and C
Wire external 24 VAC transformer into a constant power source
other than the heating, ventilating, air conditioning equipment
(HVAC) blower circuit. The transformer can be powered off the
120 VAC line at the junction box before it enters the HVAC.
Connect the 24 volt side of the transformer to the “R” and “C”
terminals on the Humidifier Control.
NOTES:
• The Humidifier Control must be continuously powered for
proper functionality.
• The minimum VA required is:
2.0 VA for humidifier Models 110, 112, 445, 448, 700 (almond
colored humidifier only), 760, and 768.
10.0 VA for humidifier Models 220, 224, 400 Series, 440,
500 Series, 550, 558, 600 Series, and 700 Series (gray colored
humidifiers only).
STEP 12: Humidifier Wiring – See Figures K through Q
Strip the wires used for all Humidifier Control terminal
connections 1/4 inch.
NOTES:
• In order for the humidifier to operate, the HVAC blower must
be running and the Humidifier Control must be calling for
humidity.
• There are several ways to detect HVAC blower operation.
See the wiring diagrams for options.