-
Active Filter bigger than 10% of CT RMS rate
-
CTs installed on source (PCC) side (auto CT not
possible for load side CT installation)
-
Only one CT per phase (not possible for
summation CTs)
-
CTs are part of below standard range:
600
750
1000
1250
1500
2000
2500
3000
3500
4000
Table 4.6 Primary Rating [A]
Most restrictions on the current transformers comes from
the installation, such as necessary cable length,
temperature conditions, square section of conducts,
standard or split core layout, etc. A broad range of
different current transformers can be used independently
of brand and type.
For specific CT requirements contact the local supplier or
go to
http://www.deif.com/Download_Centre/Search.aspx?search-
string=dct:
Secondary Primary
Accuracy Burden
Type
Description
5 or 1A
30–
7500A
0.2–0.5-1 1.0–45V
A
ASR
ASK
EASR
EASK
Measuring
current
transformer
for cables and
bus bars
5 or 1A
100–
5000A
0.5–1
1.25–30V
A
KBU
Split core
current
transformer
5 or 1A
5 or 1A
0.5–1
15–30V
A
KSU/
SUSK
Summation
current
transformer
Table 4.7 Standard CT Range from Deif - Fits Most Applications
4.5.9 Summation Transformers
Multiple current sources:
If the filter is to compensate current from several sources,
summation CTs need to be installed. This is often the case
if the filter is installed in systems with a generator backup
or where the filter is only to compensate a limited number
of loads.
M
M
M
PCC1
130BB515.11
AAF
G
Figure 4.34 Summation CTs on generator backup applications
(PCC-side). Filter compensates full current of transformer and
generator.
M
M
M
AAF
PCC1
130BB516.11
Figure 4.35 Summation CTs example for individual harmonic
compensation (load side).
How to Install
VLT Active Filter AAF 00x
4-26
MG.90.V2.22 - VLT
®
is a registered Danfoss trademark
4
4
