- General Electric Computer Accessories User Manual

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• Chapter 2 Faults and Troubleshooting Innovation Series Medium Voltage GP Type - G Drives GEH-6385
No. Name Type Description
91 AC line freq high Alarm
The AC line freq high alarm occurs when the control firmware detects that the
frequency of the AC line is above the value of Over freq alm level, which has
a suggested value of nominal frequency plus 17.3 rad/sec.
The frequency value used for this comparison is a low-pass filtered version of
the fastest version. The filter is set to .2 rad/sec as a default, so transient
over-frequency values are allowed above the threshold value without causing
this alarm.
This alarm will cease once the filtered value of filtered frequency has
decreased to below the value of Over freq alm clear, which has a suggested
value of nominal frequency plus 15.7rad/sec.
Primary causes:
AC line frequency is marginally excessive.
Possible configuration faults:
Source has been applied 60hz while the factory setup value, AC grid
frequency was at 50hz.
Possible board failures:
VATF-SRC
FOSA
BICM
DSPX
92 AC line under freq Trip The AC line under freq trip fault occurs when the control firmware detects that
the frequency of the AC line is below the value of Under freq flt level, which
has a suggested value of nominal of 50% of nominal.
The frequency value used for this comparison is a low-pass filtered version of
the fastest version. The filter is set to .2 rad/sec as a default, so transient
under-frequency values are allowed below the threshold value without
causing this trip fault.
Primary causes:
AC line frequency is low.
Possible configuration faults:
Source has been applied at 50hz while the factory setup value, AC grid
frequency was at 60hz.
Possible board failures:
VATF-SRC
FOSA
BICM
DSPX