6
2.4 Current Transformer Setup
Set up the CT according to the
PM295 User’s Guide
Rev. A1, Section 3.3.7
or in the
PAS295 User’s Guide
Rev. A1, Section 4.2.1.
2.4.1 Direct Measurement (Clamps)
All clamps with nominal secondary current 1A require the CT to be set at the
nominal primary current,
except
for the 120A/0.12A clamp, which requires
the CT to be set to 1000.
FLEX sensors with nominal secondary voltage 3V require the CT to be set at
the nominal primary current.
2.4.2 Measurement via External CTs ( Special
Cable)
The CT value should be set according to the following formula:
CT = (I
p
/ I
s
)
•
(I
cp
/I
cs
)
•
0.005
where:
I
p
= external Current Transformer primary nominal current
I
s
= external Current Transformer secondary nominal current
I
cp
= Clamp primary nominal current
I
cs
= Clamp secondary nominal current
Examples:
1. When measurement is of secondary of current transformer
3000/5
via
clamp
1000/1
, then
I
P
= 3000,
I
S
= 5,
Ic
=1000,
C.T.
= (3000/5)
•
(1000/1)
•
0.005
= 3000
.
2. When measurement is of secondary of current transformer
5000/1
via
clamp
120/0.12
, then
I
P
= 5000, I
S
= 1,
C.T.
= (5000/1)
•
(120/0.12)
•
0.005 = 25,000
.
Summary of Contents for PNA295-1
Page 1: ...PNA295 1 Portable Network Analyzer Installation and Operation Manual BG0149 Rev B...
Page 2: ...PNA295 1 Portable Network Analyzer Installation and Operation Manual...
Page 18: ...13 Figure 2 3 PNA295 1 Connections for 4 Wire System Direct Connection...
Page 19: ...14 Figure 2 4 PNA295 1 Connections for 4 Wire Grounded Delta System Direct Connection...
