Quick Reference Owner manual

13
Publication 193-QR003B-EN-P - October 2009
Figure 7: External CT Connection Diagrams
External Potential (Voltage) Transformer Application
(Cat. No. 193/592-EC5_ _)
The E3 Plus Overload Relay Catalog Number 193/592-EC5_ _ can be used with external
step-down potential transformers (PTs). The PT ratio is programmed into the E3 Plus by
entering the primary winding rating into Parameter 289, PT Pri, and the secondary winding
rating into Parameter 290, PT Sec. The voltage mode is also programmed into the E3 Plus by
selecting the appropriate mode in Parameter 156, Volt Mode. The E3 Plus will support Wye,
Delta, and Open Delta voltage modes with potential transformers.
IE
C
NEMA
L1
L2
L
3
L1
L2
L
3
E
3
E
3
M
M
K1
T1
/2
T1
T2
T
3
T2
/4
T3/6
T
L1
/1
L2
/3
L3/5
L
T1
/2
T2
/4
T
3/6
L1
/1
L2
/3
L
3/5
Primar
y
C
urren
t
Tr
a
n
s
f
o
rm
e
r
s
Primar
y
C
urren
t
Tr
a
n
s
f
o
rm
e
r
s