16
•
When the modulating furnace is installed with a com-
municating thermostat and a non-communicating a/c
unit, the IFC will open the Y1 relay to turn off the con-
densing unit
•
Log and display an auxiliary open error code
•
Once the auxiliary switch re-closes the IFC reverts
back to normal operation
Hum Terminals A pair of ¼” HUM terminals are located on
the board to power a humidifier. These are dry contacts rated
at 1 amp. A typical application of these contacts would be to
supply one of the Hum contacts with power from the L1 ter-
minal and connect the remaining Hum terminal to a humidi-
fier transformer primary. When used with the CTK02** or
CTK03 thermostat, these contacts will close with a call for
humidity and the furnace indoor blower will be powered at
continuous fan speed. When used with a 24 volt control sys-
tem, the Hum contacts will close on a call for heat when the
induced draft blower is powered.
EAC Terminal A ¼” EAC terminal is provided. Any time the
indoor blower motor is powered, the EAC terminal will be
powered. Contact is rated for 1 amp
Flame Proving. Flame signal is continuously monitored by
the IFC. The flame rod, flame rod wire and proper grounding
are all critical to proving the presence of flame. Because of
the design of the Honeywell flame proving system, reading
flame signal with a microamp meter will not provide reliable
and consistent results and is therefore not a recommended
practice. The IFC has a built in warning (E6) if flame signal
is approaching the low threshold.
Field Test Mode This feature can be used by the service
technician to quickly bring a furnace up to high fire. Entering
field test mode will by-pass the staging routine and allow the
furnace to run at 100% of rated input. To use field test mode;
during a call for heat, press the fault recall button twice within
5 seconds, the display will change to Ft, then press and
hold the fault recall button for a few seconds until the display
flashes Ft. The furnace will stay in field test mode for 5 min-
utes or until the call for heat is removed.
Dual 7 Segment Displays The modulating furnace IFC has
dual 7 segment displays to provide service information. This
information includes; present thermostat demand, CFM, and
fault codes.
Fault Recall This feature allows the service person to check
for any fault history. The board memory is capable of record-
ing and storing 10 fault codes. To use this feature, the fur-
nace must not have an existing thermostat call. Pressure
fault recall button from 2-5 seconds (until the display goes
blank) then release, all faults will be displayed one at a time,
beginning with the most recent, max of 3 consecutive faults
will be stored. When all errors have been displayed the dis-
play returns to ON. To erase stored faults, hold the fault
recall button until the display starts flashing, then release.
T
O
PREVENT
POSSIBLE
EQUIPMENT
DAMAGE
,
PROPERTY
DAMAGE
,
PERSONAL
INJURY
OR
DEATH
,
THE
FOLLOWING
BULLET
POINTS
MUST
BE
OBSERVED
WHEN
INSTALLING
THIS
UNIT
.
WARNING
P
OSSIBLE
PROPERTY
DAMAGE
,
PERSONAL
INJURY
OR
DEATH
DUE
TO
FIRE
,
EXPLOSION
,
SMOKE
,
SOOT
,
CONDENSATION
,
ELECTRICAL
SHOCK
OR
CARBON
MONOXIDE
MAY
RESULT
FROM
IMPROPER
INSTALLATION
,
REPAIR
OPERATION
,
OR
MAINTENANCE
OF
THIS
PRODUCT
.
WARNING
•
Centrally locate the furnace with respect to the proposed
or existing air distribution system.
•
Ensure the temperature of the return air entering the fur-
nace is between 55°F and 100°F when the furnace is heat-
ing.
•
Provide provisions for venting combustion products out-
doors through a proper venting system. Special consider-
ation should be given to vent/flue pipe routing and combus-
tion air intake pipe when applicable. Refer to
Vent/Flue
Pipe and Combustion Air Pipe -Termination Locations
for
appropriate termination locations and to determine if the
piping system from furnace to termination can be accom-
plished within the guidelines given.
NOTE:
The length of
flue and/or combustion air piping can be a limiting factor in
the location of the furnace.
•
Locate the furnace so condensate flows downwards to the
drain. Do not locate the furnace or its condensate drain-
age system in any area subject to below freezing tem-
peratures without proper freeze protection. Refer to
Con-
densate Drain Lines and Trap
for further details.
•
Ensure adequate combustion air is available for the fur-
nace. Improper or insufficient combustion air can expose
building occupants to gas combustion products that could
include carbon monoxide. Refer to
Combustion and Ven-
tilation Air Requirements.
•
Set the furnace on a level floor to enable proper conden-
sate drainage. If the floor becomes wet or damp at times,
place the furnace above the floor on a concrete base sized
approximately 1-1/2" larger than the base of the furnace.
Refer to the
Horizontal Applications and Considerations
for leveling of horizontal furnaces.
•
Ensure upflow or horizontal furnaces are not installed di-
rectly on carpeting, or any other combustible material. The
only combustible material allowed is wood.
•
A special accessory subbase must be used for upright
counterflow unit installations over any combustible mate-
rial (including wood). Refer to subbase instructions for
installation details. (
NOTE:
A subbase will not be required
if an air conditioning coil is located beneath the furnace
between the supply air opening and the combustible floor.
PRODUCT DESIGN
