Goodman Mfg VC8 - Manual (Page 17)

17
E
LECTRICAL
C
ONNECTIONS
R
Y C
NEU
Furnace Integrated
Control Module
Remote
Condensing Unit
(Single-Stage Cooling)
Dehumidistat
[Optional]
To apply a single-stage Heating Thermostat,
the thermostat selector switch on the
Integrated Control Module be set on
single-stage.
must
NOTE:
Single Stage Heating with Single Stage Cooling
Thermostat
Single Stage Heating with
Single Stage Cooling
R
Two-Stage Heating with Single-Stage Cooling
R
Y C
Furnace Integrated
Control Module
Thermostat
Two-Stage Heating
with
Single-Stage Cooling
Remote
Condensing Unit
(Single-Stage Cooling)
Dehumidistat
[Optional]
NEU
R
Two-Stage Heating with Two-Stage Cooling
W1 W2 Y2
Furnace Integrated
Control Module
Thermostat
Two-Stage Heating
with
Two-Stage Cooling
( )
Remote
Condensing Unit
(Two-Stage Cooling)
Dehumidistat
[Optional]
Y2 NEU
W1 W2 Y2
Thermostat Wiring Diagrams
S
INGLE
-S
TAGE
H
EATING
T
HERMOSTAT
A
PPLICATION
A single-stage thermostat with only one heating stage may be
used to control this furnace. The application of a single-stage
thermostat offers a timed transition from low to high fire. The
furnace will run on low stage for a fixed period of time before
stepping up to high stage to satisfy the thermostat’s call for
heat. The delay period prior to stepping up can be set at either
a fixed 5 minute time delay or a load based variable time be-
tween 1 and 12 minutes (AUTO mode). If the AUTO mode is
selected, the control averages the cycle times of the previous
three cycles and uses the average to determine the time to
transition from low stage to high stage.
To use a single-stage thermostat, turn off power to the furnace,
move the thermostat selection DIP switch to the OFF position.
Set the desired transition time by setting the transition delay
DIP switch to the desired ON/OFF position. Turn power back
on. Refer to the following figure.
3
4
Thermostat
Stage Delay
Move to the ON position
to select two-stage
thermostat or OFF to
select single stage
thermostat
Move to the ON position
to select Auto transition
delay or OFF for 5 minute
transition delay
Heat OFF Delay
DIP Switches
ON OFF
S1
24 V
OLT
D
EHUMIDISTAT
W
IRING
The optional usage of a dehumidistat allows the furnace’s
circulator blower to operate at a slightly lower speed (85%
of desired speed) during a combined thermostat call for cool-
ing and dehumidistat call for dehumidification. This can be
done through an independent dehumidistat or through a
thermostat’s DEHUM terminal (if available). This lower blower
speed enhances dehumidification of the conditioned air as
it passes through the AC coil. For proper function, a dehu-
midistat applied to this furnace must operate on 24 VAC
and utilize a switch which opens on humidity rise. Refer to
the “Thermostat Wiring Diagrams” figure for additional wir-
ing details.
To install/connect a dehumidistat:
1. Turn OFF power to furnace.
2. Secure the dehumidistat neutral wire (typically the
white lead) to the terminal marked “DEHUM” on the
furnace integrated control module.
3. Secure the dehumidistat hot wire (typically the black
lead) to the terminal marked “R” on the furnace
integrated control module.
4. Secure the dehumidistat ground wire (typically the
green lead) to the ground screw on the furnace junction
box. NOTE: Ground wire may not be present on all
dehumidistats.
5. Turn ON power to furnace.
To enable the dehumidify function on the integrated control
module, set the dehumidification ENABLE dipswitch from
OFF to ON.
Once the switch is set, the dehumidify function is enabled
during a combination call for cooling (T-Stat) and dehumidi-
fication (DEHUM-Stat).
9
10
DEHUM
Unused
Move to the ON position
to enable dehumidification
ON OFF
S5
F
OSSIL
F
UEL
A
PPLICATIONS
This furnace can be used in conjunction with a heat pump in
a fossil fuel application. A fossil fuel application refers to a
combined gas furnace and heat pump installation which uses
an outdoor temperature sensor to determine the most cost
efficient means of heating (heat pump or gas furnace).