Carrier 070-08/024070 Installation, Start-Up, Operating And Service And Maintenance Instructions page 50

blower motor BLWM will remain on lbr tile selected blower-
OFF delay period then switch to continuous-blower speed.
When the R-to-W-and-Y/Y2, R-to-W-and-Y/Y2-and-G, R-to-
W-and-Yl-and-Y/Y2, or R-to-W-and-Yl-and-Y/Y2-and-G
circuits are energized tile furnace control CPU will switch to
or turn on the blower motor BLWM at HEAT speed, and
begin a beating cycle. The blower motor BLWM will remain
on until the end of the prepurge period, then shut o11"lot 24
seconds then come back on at HEAT speed. When the W input
signal disappears, the furnace control begins a normal inducer
post-purge period and the blower switches to COOL speed
afler a 3 second delay. If the R-to-W-and-Y/Y2-and-G or
R-to-W-and-Yl-and-Y/Y2-and-G signals disappear at the
same time, the blower l'flotor BLWM will remain on [_)r the
selected blower-OFF delay period. If the R-to-W-and-Y/Y2 or
R-to-W-and-Yl-and-Y/Y2 signals disappear, leaving the G
signal, the blower motor BLWM will remain on lot the
selected blower-OFF delay period then switch to continuous-
blower speed.
Step 4--Wiring Diagrams
Relier to Fig. 56 lot wiring diagram.
Step 5--Troubleshooting
Relier to the service label. (See Fig. 55 Service Label.)
The Troubleshooting Guide can be a useful tool in isolating
furnace operation problems. Beginning with the word "StarL"
answer each question and flHlow the appropriate arrow to the next
item.
The Guide will help to identify the problem or failed component.
Alter replacing any component, verify correct operation sequence.
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