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I- Proper Ground and Voltage
Furnace must be properly grounded for proper perfor
-
mance. 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 the
table below. If the readings exceed the maximum
shown in table 26, make repairs before operating
the furnace
2 - In addition, measure the AC voltage from Line Hot to
Line Neutral (spade terminals) on the integrated con
-
trol. See figure 54. This voltage should be in the range
of 97 to 132 Vac.
TABLE 25
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
FIGURE 54