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Installer's
Guide
(_
Outlet Pressure Boss
\\\
Inlet Pressure
Boss (opt.)
On/OffSwitch
White-Rodgers
36G gas valve
On/Off Switch
White-Rodgers
36F gas valve
Regulator
Adjust
When
the thermostat
is satisfied,
R an(] W thermostat
contacts
open,
the gas valve
will close,
the flames
will extin-
guish,
an(] the
induced
draft
blower
will be de-energized.
The
indoor
blower
motor
will continue
to mn lbr the lan off' period
(Field
selectable
at 60, 100, 140 or 180 seconds),
then
be de-
energize(]
by the control
module.
CONTROL
AND SAFETY
SWITCH
ADJUSTMENTS
LIMIT SWITCH
CHECK
OUT
The limit
switch
is a safety
device
designed
to close
the gas
valve
should
the fllrnace
become
overheated.
Since
proper
operation
of this switch
is important
to the salety
of the
unit,
it must
be checked
out
on initial
start
up by the
installer.
To check lbr proper operation
of the limit switches,
set the
thermostat
to a temperature
higher
than the indicated
temperature
to bring on the gas valve. Restrict
the airflow by
blocking the return air (disconnecting
the indoor blower may
trip the inducer
limi0. When the furnace
reaches
the maxi-
mum outlet temperature
as shown on the rating plate, the
burners
must shut off'. If they do not shut off' alter a reason-
able time and over-heating
is evident,
a faulty limit switch is
probable
an(] the limit switch must be replace(]. Alter
checking
the operation
of the limit control, be sure to remove
the paper or cardboard
from the return
air inlet. Reler to
Service Facts for additional
instructions.
NOTE TO INSTALLER
Review the following warnings
with the owner. Review
contents
of USER'S
INFORMATION
MANUAL with the
owner.
AIRFLOW ADJUSTMENT
Check inlet an(] outlet air temperatures
to make sure they
are within
the ranges specified on the fl_rnace rating name-
plate.
If the airflow needs to be increase(]
or decreased,
see
the wiring diagram
for information
on changing
the speed of
the blower motor.
_iiiliiiiiii_iii!!i
If this is done during the cold weather months, provisions
must be taken to prevent freeze-up of all water pipes and
water receptacles. Failure to follow this warning could result
in property damage.
Whenever
your house
is to be vacant,
arrange
to have
someone
inspect
your
house
for proper
temperature.
This is very
important
during
freezing
weather.
If for
any reason
your furnace
should
fail to operate
damage
could
result,
such as frozen
water
pipes.
SEQUENCE OF OPERATION
Thermostat call for heat
R and W thermostat
contacts
close signaling
the control
module to run its sell-check
routine. Alter the control module
has verified that the pressure
switch contacts
are open an(]
the limit switch(es)
contacts
are closed, the draft blower will
be energized.
As the induced
draft blower comes up to speed, the pressure
switch contacts
will close an(] the ignitor warm up period will
begin. The ignitor will heat for approximately
20 seconds,
then the gas valve is energize(]
to permit gas flow to the
burners.
The flame sensor confirms
that ignition has been
achieve(].
After
the
flame
sensor
confirms
within
a 4 second
trial
period
that
ignition
has been
achieve(],
the
delay
to fan ON period
begins
timing.
Alter
approximately
45 seconds
the
indoor
blower
motor
will be energize(]
an(] continue
to mn during
the
heating
cycle.
Disconnect power to the unit before removing the blower
door. Failure to follow this warning could result in property
damage, personal injury or death.
This
trait
is eqtfipped
with
a blower
door switch
which
cuts
power
to the blower
and gas valve
causing
shutdown
when
the
door is removed.
Operation
with
the door removed
or ajar
can
permit
the escape
of dangerous
flmms.
All panels
must
be
securely
close(] at all times
fi)r sale operation
of the fllrnace.
INDOOR
BLOWER
TIMING
Heating:
The integrate(]
fllrnace
control
module
controls
the
indoor
blower.
The blower
start
is fixed
at 45 seconds
alter
ignition.
The FAN-OFF
period
is field selectable
by dip
switches
at 60,100,140,
or 180 seconds.
The factory
setting
is 100 seconds
(See wiring
diagram).
Cooling:
The fan delay
off period
is factory
set at 0 seconds.
The option
lbr 80 second
delay
off is field selectable
(See
wiring
diagram).
ROOM AIR THERMOSTAT
HEAT ANTICIPATOR ADJUSTMENT
Set the thermostat
heat anticipator
according
to the current
flow measured,
or the settings
lbund in the notes on the
furnace
wiring diagram
(found in the SERVICE
FACTS or
inside the lurnace
casing).
INSTRUCTIONS TO THE OWNERS
In the event
that
electrical,
fuel, or mechanical
failures
occur,
the owner
should
immediately
turn
the gas
30
18-CD19D6-27
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