40
440 01 1051 02
Specifications are subject to change without notice.
Figure 40
Electrical Connections
NOTE: Junction Box can be
mounted to either the left or right
side.
25
−
24
−
90
−
2
Models may
have 1 or 2
pressure
switches
NOTE: 115 VAC/60Hz/single
−
phase
Operating voltage range*: 127 VAC max, 104 VAC min.
* Permissible limits of voltage at which unit will operate satisfactorily
115V. 60 Hz
W
W
W
Low Voltage
Terminal Board
R
R
BK
Ground
Connection
Box
G
HOT
NEUT
.
G
G
Y
G
ON
OFF
Representative drawing only, some models may vary in appearance.
Furnace Control Fuse
The 24V circuit contains a 5
−
amp, automotive
−
type fuse located
on furnace control. (See
Figure 41
) Any electrical shorts of 24V
wiring during installation, service, or maintenance may cause fuse
to blow. If fuse replacement is required, use only a fuse of identical
size (5 amp.)
Blower Off
Delay Jumper
Control Board
Figure 41
FUSE
25-24-98
Diagnostic Light
24 VAC
HUM
115 VAC
HUM
EAC
Ductwork and Filter
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in
personal injury or death.
Do NOT draw return air from inside a closet or utility
room where furnace is located. Return air duct
MUST be sealed to furnace casing.
!
WARNING
Installation
NOTE:
Design and install the air distribution system to comply with
Air Conditioning Contractors of America manuals and/or NFPA
pamphlets 90A and 90B or other approved methods that conform
to local codes and good trade practices.
1. When furnace supply ducts carry air outside furnace area,
seal return air duct to furnace casing and terminate duct
outside furnace space.
2. Install air conditioning cooling coil (evaporator) on outlet
side of furnace.
3. For furnaces installed without a cooling coil it is
recommended that the outlet duct be provided with a
removable access panel. This panel should be accessible
when the furnace is installed so the exterior of the heat
exchanger can be viewed for inspections. The access panel
MUST
be sealed to prevent leaks.
4. If separate evaporator and blower units are used, install
good sealing dampers for air flow control. Chilled air going
through the furnace could cause condensation and shorten
the furnace life.
NOTE:
Dampers (field supplied) can be either automatic or
manual. Manually operated dampers
MUST
be equipped with a
means to prevent furnace or air conditioning operation unless
damper is in the full heat or cool position.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in
personal injury or death.
Cool air passing over heat exchanger can cause
condensate to form resulting in heat exchanger
failure.
!
WARNING
Connections
NOTE:
On upflow installations, return air can enter through either
side, both sides, or the bottom. On horizontal installations the
return air must enter through the knockout opening in the lower
panel of the furnace. Return air
can not
enter through rear of the
furnace. When the furnace is located in an area near or adjacent to
the living area, the system should be carefully designed with
returns to minimize noise transmission through the return grille.
Any blower moving a high volume of air will produce audible noise
which could be objectionable to when the unit is located very close
to living areas. It is advisable to route the return air ducts under the
floor or through the attic.
1. For side connections using a 16
″
x 25
″
(406.4 x 635mm)
filter, cut out the embossed area shown in
Figure 42
. This
will provide a 14
1
/
2
″
x 22
1
/
2
″
(368.3 x 571.5mm)
approximate opening.
