Rheem RGFG Installation Instructions Manual page 38

FIGURE 33
WIRING FOR OPTIONAL DEHUMIDIFICATION OPERATION AND HUMIDIFICATION WITH OPTION-
AL HUMIDIFIER (HUMIDIFIER WITH INTERNAL POWER SUPPLY) (FOR USE WITH NON-COMMU-
NICATING THERMOSTATS)
FIGURE 34
HUMIDISTAT USED TO CONTROL DEHUMIDIFICATION IN COOLING ONLY (NO HUMIDIFIER)
(FOR USE WITH NON-COMMUNICATING THERMOSTATS)
permanently reduced by approximately
15% giving less than optimal perfor-
mance and possibly causing problems.
It is not recommended to leave this
switch in the "ON" position without a
humidistat installed.
Control of dehumidification in cooling
and/or humidification in heating can be
done with a variety of methods depend-
ing on whether there is a communicat-
ing thermostat or a humidistat available
and depending on the type of operation
desired.
With systems configured with communi-
cating thermostats and condensers,
dehumidification is controlled by the
condenser and is not affected by the
position of dipswitch S5-1 or the volt-
age (or lack of voltage) at the thermo-
stat terminal labeled "HUM STAT".
To determine which wiring diagram and
method to use, select from the following
configurations:
38
A. HUMIDIFICATION CONTROL ONLY
WITH NO DEHUMIDIFICATION
(REQUIRES OPTIONAL HUMIDIFI-
ER).
A1. WITH COMMUNICATING
THERMOSTAT
Humidifier control is included
with the (-)HC-TST412MDMS
(modulating, non-communicat-
ing) and (-)HC-TST550CMMS
(full-color communicating)
model thermostats. However, it
is not included with the (-)HC-
TST501CMMS model commu-
nicating thermostat. The latter
thermostat should not be used
if humidification control is
required. To wire the furnace for
humidification control using
either the (-)HC-TST412MDMS
or the (-)HC-TST550CMMS,
refer to the wiring diagram in
Figure 31. Be sure not to install
the jumper between "R" and
"HUM STAT" on the furnace
control. Installing this
jumper will operate the
humidifier any time there is
a heat call. Without the
jumper, the humidification
call from the thermostat
must be active and a heat
call must be present with the
blower running.
A2. WITH NON-COMMUNICAT-
ING THERMOSTAT
A2-1 CONTINOUS HUMID-
ST-A1161-01
A2-2 CONTROLED
ST-A1161-02
B. DEHUMIDIFICATION CONTROL
WITH NO HUMIDIFICATION
B1. For communicating ther-
mostats listed with this fur-
nace, dehumidification is
controlled automatically
when selected at the ther-
mostat and additional wiring
is not necessary. The actual
airflow demand (reduced for
dehumidification) is request-
ed of the furnace by the
condenser.
IFIER OPERATION
DURING HEATING.
For continuous humid-
ifier operation during
heating, refer to
Figure 31 and make
sure to install the
jumper between the
thermostat terminals
labeled "R" and "HUM
STAT". A separate
humidistat is not
required for this con-
figuration and the
humidifier will turn on
whenever there is a
call for heat and the
blower is running.
HUMIDIFIER OPERA-
TION USING A
HUMIDISTAT
(REQUIRES OPTION-
AL HUMIDISTAT).
Controlled humidifica-
tion can be accom-
plished using a
humidistat as shown
in Figures 32 or 33.
These figures show
installation of a humid-
ifier with external and
internal power sup-
plies respectively.
Dehumidification oper-
ation will be disabled if
the dipswitch S5-1 is
in the "OFF" position.
If this switch is in the
"ON" position, dehu-
midification control will
be active.