Line Attenuation - ABB ETL600 Instruction Manual

ETL600
C'
k
Return loss
impedance meter
Fig. 7-5
C'
k
1)
CF
Fig. 7-6
7.2.2.

Line attenuation

The line attenuation should be measured over the whole frequency
range of the coupling filter and of the line traps. If possible these
measurements should be carried out with the transmission line
Commissioning
1KHW001489-EN
Return loss: phase-to-ground
Z
L
CF
CF coupling filter
a = 20 log
r
and
Z0 rated impedance
Z actual input impedance
Test circuit using a dummy load for measuring return
loss in the case of single-phase coupling
2Z
L
2)
BT
Remarks
1)
2)
a = 20 log
r
Z0
Z
Return loss
CF
meter
BT
Test circuit using a dummy load for measuring return
loss in the case of phase-to-phase coupling
Z0 + Z
Z0 - Z
2)
C'
k
1)
CF
short connection
unscreened insulated lead
1 m above ground
Z0 + Z
Z0 - Z
rated impedance
actual input impedance
coupling filter
balancing transformer
November 2005
ABB Switzerland Ltd
7-7