Integrated Control Board - Lennox G61MPVT-36B-070 Installation Instructions Manual

Integrated Control Board

HEAT
STAGING
DELAY
JUMPER
BLOWER
OFF DIAGNOSTIC
LED
DELAY
JUMPER
G61MPVT units are equipped with a two−stage, variable
speed integrated control. This control manages ignition
timing, heating mode fan off delays and indoor blower
speeds based on selections made using the control dip
switches and jumpers. The control includes an internal
watchguard feature which automatically resets the ignition
control when it has been locked out. After one hour of con-
tinuous thermostat demand for heat, the watchguard will
break and remake thermostat demand to the furnace and
automatically reset the control to relight the furnace.
Heat Staging Jumper
The heat staging jumper is factory−positioned in the
NONE position for use with a two−stage thermostat. If a
single−stage thermostat is to be used, the jumper must be
repositioned.
When the G61MPVT unit is used with single−stage ther-
mostat −− The heat staging jumper is used to determine the
second stage on delay. The jumper may be positioned to
TWO−STAGE, VARIABLE SPEED INTEGRATED CONTROL BOARD
BLOWER
OPERATION
DIP
SWITCHES
OPERATIONAL
LEDS
FIGURE 33
provide either a 10−minute or a 15−minute delay before sec-
ond−stage heat is initiated.
Blower−Off Delay Jumper −− The heating mode blower−on
delay of 45 seconds is not adjustable. The heating mode
blower−off delay (time that the blower operates after the
heating demand has been satisfied) can be adjusted by
moving blower−off delay jumper on the integrated control
board. The unit is shipped from the factory with a blower−off
delay of 90 seconds. The blower off delay affects comfort
and is adjustable to satisfy individual applications. Adjust
the blower off delay to achieve a supply air temperature be-
tween 32° and 43°C (90° and 110°F) at the exact moment
that the blower is de−energized. Longer off delay settings
provide lower supply air temperatures; shorter settings
provide higher supply air temperatures. Settings of 60, 90,
120 and 180 seconds are available.
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