Manual

Installation Guide
69-2036EFS—07 
Loosen captive cover
screw. Slide cover out from
front.
11
M24754
WIRIng
CAUTION: Voltage Hazard.
Before wiring to HVAC terminals, disconnect HVAC
equipment power. Ensure humidifier is not plugged in.
Low-Voltage Terminals
24V AC power for electronic humidistat.
HUM Low-voltage humidistat (or thermostat) terminals control
humidifier operation.
C, R Connects to HVAC system transformer terminals (or relay
transformer fan control R and C) to ensure HVAC power
is present before humidifying. This can be disabled by
changing DIP switch 4 (see page 16).
RT Connects to thermostat R terminal, which is normally
switched to call for fan.
GT, GT connects to thermostat G terminal. GF connects to
fan board G terminal. Thermostat G passes through the
normally-closed (NC) relay contacts to GF, allowing fan
activation. When TrueSTEAM is ready to provide humidity
to the home, it will take control of the fan by forcing power
from RT to GF (if not already activated).
EXT When a 24-vac fan board is not used to control blower
(hydronic or cooling-only applications), this connection
with GF provides dry-contact closure for fan calls. EXT/
GF may be wired to a low-voltage relay control center to
provide line-voltage fan control.
M24895
24V
24V
HUM
HUM
C
GT
R
RT
GF
EXT
GF
M24893
Route wires through the raised harness tabs and out the notch at
the rear of the chassis. Ensure wires are secure and do not inter-
fere with assembly of cover.
Tabs Notch