63230-400-204/A1
February 2002
Chapter 5—Wiring
Wiring CTs, PTs, and Control Power to the Circuit Monitor
The circuit monitor supports a variety of 3-phase power system wiring
connections, including 3-wire delta and 4-wire wye. The metering voltage
inputs support direct connection to 3-phase power systems from
208V L–L/120V L–N through 600V L-L/347V L–N. In addition, the circuit
monitor supports higher voltages through potential transformers (PTs). The
circuit monitor can also be used with line-to-line rated PTs connected line to
neutral, which results in a line-to-neutral voltage of 69 V. Table 5–2 lists the
supported system connections and references the wiring diagrams on pages
35 through 44. Figures 5–4 through 5–13 beginning on page 35 show wiring
to the circuit monitor for connections to the current transformers CTs, PTs,
and control power. Figure 5–14 on page 45 shows dc control power.
WIRING CTS, PTS, AND CONTROL
POWER TO THE CIRCUIT MONITOR
Table 5–2: Supported Types of System Connections
System Wiring
3∅, 3-Wire
Delta
Number
of CTs
Auxiliary
CT
Number
of PTs
2
None
2
3
None
3
None
PT
Connection
Currents
Voltages
System
Type➀
Figure
Number
A, B➁, C
A-B, B-C, C-A➁
3∅3W2CT
(30)
Figure 5–5
on page 36
2
A, B, C
A-B,B-C,C-A➁
3∅3W3CT
(31)
Figure 5–6
on page 37
3
A, B, C, N➁
A-N, B-N, C-N
A-B➁, B-C➁,
C-A➁
3∅4W3CT
(40)
Figure 5–7
on page 38
3∅4W4CT
(41)
Figure 5–8
on page 39
Open Delta
Wye-Wye
3∅, 4-Wire
Wye,
Ground
4
Neutral
3
A, B, C, N, G➁
A-N, B-N, C-N
A-B➁, B-C➁,
C-A➁
3
None
2
A, B, C, N➁
A-N, B-N➁, C-N
A-B➁, B-C➁,
C-A➁
3∅4W3CT2PT Figure 5–11
(42)
on page 42
A, B, C, N, G➁
A-N, B-N➁, C-N
A-B➁, B-C➁,
C-A➁
3∅4W4CT2PT Figure 5–12
(43)
on page 43
Open Wye
4
Neutral
2
➀ The “system type” is a code assigned to each type of system connection.
➁ Indicates a value that is calculated rather than measured directly.
© 2002 Schneider Electric All Rights Reserved
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