Lennox ML193UH045P36B Unit Information page 12

Fan Time Control
Heating Fan On Time
The fan on time of 30 seconds is not adjustable.
Heating Fan Off Time
Fan off time (time that the blower operates after the heat
demand has been satisfied) can be adjusted by moving the
jumper to a different setting. The unit is shipped with a fac­
tory fan off setting of 120 seconds. For customized comfort,
monitor the supply air temperature once the heat demand
is satisfied. Note the supply air temperature at the instant
the blower is de-energized.
Adjust the fan-off delay to achieve a supply air temperature
between 90° - 110° at the instant the blower is de-ener­
gized. (Longer delay times allow for lower air temperature,
shorter delay times allow for higher air temperature). See
figure 8.
Cooling Fan On Time
The fan on time is 1 seconds and is not adjustable.
Cooling Fan Off Time
The control has a 60 second fan off delay after cooling de­
mand has been met. This delay is factory set and not ad­
justable.
HEAT FAN‐OFF TIME IN SECONDS
NO JUMPER
To adjust fan-off timing, reposition jumper across pins to
achieve desired setting.
60 Second 90 Second
off Time off Time
FIGURE 8
120 Second 180 Second
off Time off Time
Page 12
Twinning 2 ML193UH Furnaces
Integrated control 103085 is equipped with a provision to
"twin" (interconnect) two(2) adjacent furnaces with a com­
mon plenum such that they operate as one (1) large unit.
When twinned, the circulating blower speeds are synchro­
nized between the furnaces. If either furnace has a need to
run the blower, both furnaces will run the blower on the
same speed. The cooling speed has highest priority, fol­
lowed by heating speed and fan speed.
Field installation of twinning consists of connecting wires
between the "C" and "Twin" terminals of the two controls.
The 24 VAC secondary of the two systems must be in
phase. All thermostat connections are made to one control
only. Figure 9 show wiring for two-stage and single stage
thermostats.
The twinned furnace without thermostat connections is to
have the call for heat supplied by an external 24VAC isola­
tion relay to prevent its rollout switch from being bypassed
by the other twinned furnace. The coil of the isolation relay
connects from the thermostat "W" to 24 VAC common. The
contacts of the relay connect "R" to "W" on the non-thermo­
stat twin.