Lennox EL195DF SERIES User Manual page 39

I− Proper Ground and Voltage
A poorly grounded furnace can contribute to premature ig-
nitor 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 50. 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 the table below. If the read-
ings exceed the maximum shown in table 1, make re-
pairs before operating the furnace.
CHECK VOLTAGE BETWEEN LINE NEUTRAL
AND LOW VOLTAGE C" TERMINAL
Red LED
Recall
2 − In addition, measure the AC voltage from Line Hot to
Line Neutral (spade terminals) on the integrated con-
trol. See figure 50. This voltage should be in the range
of 97 to 132 Vac
Furnace Status
Power On Furnace Idle
CAI / Ignitor Energized
Indoor Blower Energized
CHECK VOLTAGE BETWEEN LINE HOT
AND LINE NEUTRAL
Red LED
Recall
FIGURE 50
Page 39
TABLE 17
Measurement VAC
Expected Maximum
0.3
0.75
Less than 2
2
5
10