Table of Contents
Advertisement
CT specification:
– 1 or 5A secondary current rating,
– 15 VA burden for up to 30 meters with 2.5 mm² cable. For longer cables lengths refer to
case of the CT is shared with other loads, the VA burden shall be adapted accordingly,
– Class 1 resolution or better,
– Primary side current rating should be sufficient to monitor the total line current (including transient phenomena
such as drive/motor starts).
The APCQ capacitor bank is provided with HITACHI ENERGY RVC/RVT controller with automatic adaptation to net-
work phase-rotation.
Maximum rms current of the
downstream loads (including starting
current of DC drives):
X1 = ..... Arms
Multiply X1 by
1.6:
X2 = ..... Arms
CT cables > 30 meters?
NO
Select the CT such that:
• rating at primary ≥ X2
• rating at secondary : 5A
• burden ≥ 15VA
• class 1 accuracy or better
5.4.9. Current transformer connection
STATUS
Approved
YES
Section of CT cables
2.5 mm²? (recommended)
YES
Determine the length of
CT cables (meters)
X3 = (L x 0.007 x 26) + 10
Select the CT such that:
• rating at primary ≥ X2
• rating at secondary : 5A
• burden ≥ X3 VA
• class 1 accuracy or better
Figure 25: Flow chart for CT determination
SECURITY LEVEL
Public
NO
L = ..... M
X3 = ..... VA
DOCUMENT ID
9AKK107680A4136
AP CQ CAPA CITO R BA NKS
Figure 25
here below. In
Determine the length (m) and
resistance (Ω/m) of
CT cables (meters)
L = ..... M
R = ..... Ω/m
X4 = (L x R x 25) + 10
X4 = ..... VA
Select the CT such that:
• rating at primary ≥ X2
• rating at secondary : 5A
• burden ≥ X4 VA
• class 1 accuracy or better
REV.
LANG.
PAGE
E
en
22/47
© 2022 Hitachi Energy. All rights reserved.
Advertisement
Table of Contents
