32
Twinning
Twinning operation of two furnaces, installed side-by-side, con-
nected by a common duct system with main power supplied by
the same source, and controlled by a common thermostat can
be done with the UT Electronic Controls 1194-250 integrated
control boards .
IMPORTANT: Only twin furnaces with identical control boards .
IMPORTANT: Only bottom returns can be used . No more than
two furnaces can share the same supply and return . Furnaces
must have same heating and blower capacity . Twinning furnaces
must operate off the same phase of power .
It should be noted that both blowers will run simultaneously when
there is a call for heating, cooling or fan .
NOTE: Duct system must be adequate to provide correct airflow
to each furnace for supply and return .
UT ELECTRONIC CONTROLS
1194-250 CONTROL BOARD
(62-104058-02)
1 . Single Stage Operation
a . Control board “ONE” is on furnace connected to the ther-
mostat .
b . The 24 VAC supply to both control boards must be in
phase with each other .
c . Connect the “C,” “W” and “TWIN” terminals to counter-
parts on each control .
d . Twinning is automatically detected when wire is con-
nected to the twin terminal on both controls . If twinning
is detected and then lost in the same power cycle, the
furnace control will declare and display fault code 20 at
the seven-segment display .
See Figure 28 for twinning wire diagram for 1-stage thermostat .
See Figure 29 for twinning wire diagram for 2-stage thermostat .
TWINNING
FURNACE TWINNING INSTALLATIONS
Summary of Contents for 801C Series
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