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Flame (microamp) signal is an electrical current which
passes from the integrated control to the sensor during
unit operation. Current passes from the sensor through
the flame to ground to complete a safety circuit.
To Measure Flame Signal - Integrated Control:
Use a digital readout meter capable of reading DC micro
-
amps.
See figure 8 and table 6 for flame signal check.
1 - Set the meter to the DC amps scale.
2 - Turn off supply voltage to control.
3 - Remove sensor wire from integrated control.
4 - Connect (-) lead to flame sensor wire.
5 - Connect (+) lead to Terminal FS on integrated control.
6 - Turn supply voltage on and close thermostat contacts
to cycle system.
7 - When main burners are in operation for two minutes,
take reading.
TABLE 6
Flame Signal in Microamps
Normal
Low
Drop Out
1.5 or greater
0.5 - 1.4
0.4 or less
Measuring Flame Signal
(Typical Furnace and Control)
Flame
Sensor
Flame Sensor
Wire
Integrated
Control
Remove Sensor Wire from
Integrated Control and
Connect Alligator Clip (−)
to Flame Sensor Lead
Flame Sensor
Terminal
Remove Sensor Wire from
Integrated Control and
Connect Alligator Clip (+)
to Terminal on Control
(+)
DIGITAL METER
(+) To Control
Sensor
Terminal
(-) To
flame
sensor
Set dial to measure dc microamps
(+)
Red Collar
Indicates
Positive
Lead
FIGURE 8
