Lennox EL297DFV Series - Page 63

Page 63
I- Proper Ground and Voltage
A poorly grounded furnace can contribute to premature
ignitor failure. Use the following procedure to check for
ground and voltage to the integrated control.
1 - Measure the AC voltage between Line Neutral
(spade terminals) and “C” terminal (low voltage
terminal block) on the integrated control. See
FIGURE 53. A wide variation in the voltage between
Line Neutral and “C” as a function of load indicates
a poor or partial ground. Compare the readings to
TABLE 29. If the readings exceed the maximum
shown, make repairs before before operating the
furnace.
Note - Igntion control in FIGURE 53 is typical. Use
for reference only.
2 - In addition, measure the AC voltage from Line Hot
to Line Neutral (spade terminals) on the integrated
control. See FIGURE 53.This voltage should be in
the range of 97 to 132 Vac.
TABLE 29
Furnace Status
Measurement VAC
Expected Maximum
Power On Furnace Idle 0.3 2
CAI/Ignitor Energized 0.75 5
Indoor Blower Energized Less than 2 10
CHECK VOLTAGE BETWEEN LINE NEUTRAL
AND LOW VOLTAGE “C” TERMINAL
CHECK VOLTAGE BETWEEN LINE HOT
AND LINE NEUTRAL
W1 W2 G
Y2
Y1
CC
RDHL ODS
W1 W2 G
Y2
Y1
CC
RDHL ODS
FIGURE 53