Lennox ML193DFE Series Unit Information page 12

To Measure Flame Signal - Integrated Control:
Use a digital readout meter capable of reading DC micro-
amps. See FIGURE 10 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.
Flame Signal In Microamps
Normal Low
1.5
0.5 - 1.4
(+)
Remove Sensor Wire from
Intergrated Control and
Connect Alligator Clip (+)
to Terminal on Control
Measuring Flame Signal
Drop Out
0.4
Flame Sensor
Terminal
Flame Sensor
Wire
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.
Intergrated
Control
(+) To Control
Sensor T erminal
FIGURE 10
Page 12
Remove Sensor Wire from
Intergrated Control and
Connect Alligator Clip (−)
to Frame Sensor Lead
Multi−Meter
Set Dial to DC MicroAmps
(+)
(−) T o Flame
Terminal