ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL SUPPLEMENT
Rev.
5
MM-24-2
Nov
5/13
24-3. Maintenance – Engine Monitor
The engine monitor instrument requires no scheduled maintenance checks, calibration, field
adjustments or field-serviceable components. Built-in self-tests start automatically on
power-up to detect instrument malfunctions. Common start-up malfunctions are caused by
a wiring anomaly. Refer to Diagram 21-5 Sheet 3 or 6, as applicable, to diagnose an open
wire or probe with a poor connection.
Refer to Section 7 for instrument replacement (para. 7-18) and inspection (para. 7-19)
procedures. In addition, inspect the instrument for proper operation. The inspection for
proper engine monitor operation should consist of either a maintenance ground run or a
maintenance test flight to compare the instrument indications to the indications observed
during normal operation. The troubleshooting and diagnosis chart, Table 24-2, will help
diagnose engine problems.
24-4. Programming Alarm Limits – Engine Monitor
The EDM-700 has programmable alarms. The alarm limits are based on factory default
settings but may be modified. Recommended alarm limit values are defined in Table 24-1.
The operator may choose to reduce these to provide additional margins or increase engine
life. Lycoming and various industry groups have additional guidance.
NOTE
Limits will reset to factory defaults when the display is switched between
Fahrenheit and Celsius.
Table 24-1. EDM-700 Recommended Alarm Limit Values
Parameter Description
Recommended
Limit
CHT
Cylinder head temperature
500°F (260°C)
TIT
Turbine inlet temperature
1650°F (900°C)
CLD
Cylinder head cooling rate -100°F/min
(-55°C/min)
DIF
Difference between highest and
lowest EGT values
500°F (280°C)
H BAT
Battery high voltage limit
30.0V
L BAT
Battery low voltage limit
24.5V
24-5. Troubleshooting – Engine Monitor
Refer to Table 24-2 to help diagnose engine problems when using the engine monitor. Not
all possible engine monitor displays are presented. Refer to the applicable engine monitor
installation and/or operation manual for a complete troubleshooting and diagnosis listing.
WARNING
Magneto checks should be conducted on the ground. They may be
conducted hovering IGE with a pilot and a mechanic to manipulate the
magneto switch, but the pilot must be prepared for sudden, complete
engine stoppage.
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