Gen II
User Manual
23-7 – Equipment and Accessory Setup and Troubleshooting
Chapter 23
Revision 4.01, Apr 2020
23.9.
– Troubleshooting Ground Loop Issues
If ground loop problems are suspected, the offending connection can usually be tracked down by
disconnecting analyzer connections one at a time to see if the problem goes away.
Non-ACES cables may induce ground loops if shields/grounds are terminated incorrectly.
Shields should be terminated at ONE END OF THE CABLE ONLY! Terminating shields at two
locations will induce ground loops and noise into the system.
Case-grounded sensors should be avoided as they connect sensor case to the engine and/or
aircraft ground, which may be at several VOLTS different ground potential than analyzer
ground. If case grounded sensors must be used, they should be used with an isolating mounting
pad.
Differential input configuration should be used for most tach/speed connections. This provides a
non-ground referenced sensing point that is very high impedance, effectively isolating the
analyzer from the tach/speed source (such as a mag pickup or coil, etc).
Single-ended input configuration should typically be used for most vibration sensor inputs.
Single-ended is required to provide a good ground reference/return for the analog signal. Some
sensors are differential, but external ACES charge amplifiers convert the sensor output
differential charge to single-ended (ground-referenced) voltage.
23.10.
– TraX
The TraX fixed based optical tracker is designed to be mounted on the inside of the wind screen.
If track is not being recorded, verify track is placed and angled in the correct position relative to
the main rotor blades. Ensure when data is being collected the lights on the tracker are on and
responding.
Revision History:
3/10/2015
1.01: Added Chapter 23.1.2 Extended Storage and revision history table and added revision history table.
Berlin
1/20/2016
2.00: Major rewrite generalizing the manual to cover both the Viper II and Cobra II. This chapter was updated
with screenshots and corrections to minor typographical errors.
East
12/6/2016
2.01: Added overload indicator definitions.
Lucas
8/22/2017
4.00: Added TraX information and updated battery information.
Boyer
4/1/2020
4.01: Updated screenshots for SP7 UI changes. Minor grammatical changes.
Shively
