MA-041
–
DGA 900 Plus - Installation & Commissioning Manual - Rev 1.1
4-Mar-22
Page 90 of 99
Figure 10-26: Bushing Alarms Configuration
To disable instantaneous Tan
δ
measurements:
▪
Select
BMT > Configuration
as shown in Figure 10-27 to verify
the ‘
Exponential
Moving Average Configuration
’. Ensure that:
−
‘
Daily Moving Average Enable
’ is
On
−
‘
Moving Average Factor Phase Angle
’
is
10000
Figure 10-27: Exponential Moving Average Configuration
10.4.5
PD Live HF Noise Threshold Measurement
The HF input noise can range over many orders of magnitude depending on the
transformer, so
the ‘Live HF Noise’
is used to estimate the input noise levels and
consequently adjust the input gains.
▪
Select
BMT > Configuration
and scroll down to the ‘Live HF Noise’ section
as shown
Figure 10-28: Live HF Noise
If
the ‘Live HF Noise’ value for any channel
exceeds 180,
scroll further down to the ‘HF
Gain Control’ section an
d select
High gain
for each affected channel as shown in Figure
