Installation guide

issatisfied,theblowermotorBLWMwilloperateanadditional90
secondsat high-coolingairflowbei\_retlansitioningbackto
continuous-blowerairflow.
WhentheRtoGcircuitisopened,theblowermotorBLWMwill
continueoperatingforanadditional5seconds,ifnootherflmction
requiresblowermotorBLWMoperation
ContinuousBlowerSpeedSelectionfromThermostat
Toselectdifferentcontinuous-blowerspeedsfi'omtheroom
thermostat,momentarilyturnofftheFANswitchorpush°
buttonontheroomthemaostatfor1=3secondsaftert!_eblower
motorBLWMisoperating.Thefl/macecontrolCPUwillshift
thecontinuous-blowerairflowfl'omthefi_ctorysettingtothe
nexthighestCFselectionairflowasshownin Fig.50.
MomentarilyminingofftheFANswitchagainatthethermo=
statwill shiftthecontinuous-blowerairflowuponemore
increment.If yourepeatthisprocedureenough,youwill
eventuallyshiftthecontinuous-blowerairflowtothelowest
CFselectionasshownin Fig.50.Theselectioncanbe
changedasmanytimesasdesiredandisstoredinthememory
tobeautomaticallyusedfbllowingapowerintem/ption.
HEATPUMP
SeeFig.56=59forflaermostatconnections.
Wheninstalledwithaheatpump,the/\1macecontlolautomatically
changesthetimingsequencetoavoidlongblowerofttimesduring
demanddefl'ostcycles.WheneverW/W1isenergizedalongwith
Y1orYY2,thefurnacecontrolCPUwilltransitiontoorbringon
theblowermotorBLWMatcoolingairflow,tow-heatairflow,or
themidrangeairflow,whicheveristhelowest.Theblowermotor
BLWMwillremainonuntilthemainburnersignite,thenshutOFF
andremainOFFfbr25 seconds before coming back on at heating
airflow. When the W/W1 input signal disappears, the Nrnace
control begins a normal inducer post-purge period while changing
the blower airflow. If YY2 input is still energized, the Nrnace
control CPU will tlansition the blower motor BLWM airflow to
cooling airflow. If Y/Y2 input signal disappears and the YI input
is still energized, the Nmace contlol CPU will transition the
blower motor BLWM to low=cooling airflow. If both the Y1 and
Y/Y2 signals disappear at the same time, the blower motor BLWM
will remain on at low-heat airflow for the selected blower=OFF
delay period. At the end of the blower-OFF delay, the blower
motor BLWM will shut OFF unless G is still energized, in which
case the blower motor BLWM will operate at continuous blower
airflow.
COMPONENT TEST
The furnace features a component test system to help diagnose a
system problem in the case of a component failure To initiate the
component test procedure, ensure that there are no thermostat
inputs to the control and all time delays have expired. Turn on
setup switch SWI°6 (See Fig. 32.)
NOTE: The component test feature will not operate if the control
is receiving any them_ostat signals or until all time delays have
expired.
The component test sequence is as follows:
a. The fimaace control CPU turns the inducer motor IDM ON
at n_edium speed and keeps it ON through step c.
b. After waiting 15 seconds, the fl/mace contlol CPU rams
the hot surface igniter ON _br 15 seconds, then OFF.
c. The fl/mace control CPU then turns the blower motor
BLWM ON at midrange airflow _br 15 seconds, then OFF.
d. After shutting the blower motor BLWM OFF, the furnace
contlol CPU shuts the inducer motor IDM OFF.
NOTE: The EA( terminals are energized when the blower is
operating.
After the component test is completed, 1 or more status codes (11,
25, 41, or 42) will flash. See Sela'ice Label on blower access panel
or Service/Stares Code Instructions fbr explanation of stares codes.
NOTE: To repeat component test, turn setup switch SWI=6 to
OFF and then back ON.
Step 6--Adjustments
SET GAS INPUT RATE
Furnace gas input rate on rating plate is %r installations at altitudes
up to 2000 ft.
In the U.S.A, the input rating for altitudes above 2000 ft must be
reduced by 2 percent _br each 1000 ft above sea tevel
In (anada, the input rating must be derated by 5 percent for
altitudes of 2000 ft to 4500 ft above sea level.
Adjust manifold pressure to obtain input rate.
Furnace input rate n-rest be within _+2 percent of input rate on
furnace rating plate.
1. Determine natural gas orifice size and manifbld pressure _br
correct input.
a. Obtain average heat value (at installed altitude) from local
gas supplier.
b. Obtain average specific gravity fl'om local gas supplier.
c. Verify Nmace model Table 11 can only be used _br model
58MVP Furnaces.
d. Find installation altitude in Table 11.
NOTE: For Canadian altitudes of 2000 to 4500 fl, use U.S.A.
altitudes of 2001 to 3000 ft in Table 11.
e Find closest natural gas heat value and specific gravity in
Table 11
£ Follow heat value and specific gravity lines to point of
intersection to find orifice size and low- and high-heat
manifbld pressure settings for proper operation
EXAMPLE: (0 2000 fi altitude)
Heating value 1050 Bmicu ft
Specific gravity 0.62
Therefbre: Orifice No. 45
Manifold pressure: 3.8-in. wc for high heat
1.6-in. wc for tow heat
* Furnace is shipped with No. 45 orifices In this example,
all main burner orifices are the cotxect size and do not need
to be changed to obtain proper input rate
42
g. Check and verify burner orifice size in furnace. NEVER
ASSUME ORIFI(E SIZE; ALWAYS (HE(K AND
VERIFY.
Adjust manifold pressure to obtain input rate
a Remove burner enclosure fiont
NOTE: Manifold pressure MUST always be measured with the
burner box cover REMOVED
b. Remove regulator seal caps that conceal adjustment screws
for low= and high=heat gas valve regulators. (See Fig. 62)
c Move setup switch SWI=2 on control center to ON posi=
tion (See Fig 32.) This keeps fl/mace locked in low-heat
operation
d. Jumper R and W/W1 fl'*ermostat connections on control to
start fl_rnace.