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PQMII POWER QUALITY METER – INSTRUCTION MANUAL
CHAPTER 2: INSTALLATION
2.2.3
3-wire System using Two CTs
The figure below shows two methods for connecting CTs to the PQMII for a 3-wire system.
The top drawing shows the standard wiring configuration using three CTs. An alternate
wiring configuration uses only two CTs. With the two CT method, the third phase is
measured by connecting the commons from phase A and C to the phase B input on the
PQMII. This causes the phase A and phase C current to flow through the PQMII’s phase B CT
in the opposite direction, producing a current equal to the actual phase B current.
Ia + Ib + Ic = 0 for a three wire system.
Ib = – (Ia + Ic)
For the CT connections above, the
S2 SYSTEM SETUP
ÖØ
CURRENT/VOLTAGE CONFIGURATION
ÖØ
PHASE CT WIRING
ÖØ
PHASE CT PRIMARY
setpoint must be set to PHASE A, B, AND C.
FIGURE 2–9: Alternate CT Connections for 3-wire System
Summary of Contents for PQM II
Page 8: ...TOC VI PQMII POWER QUALITY METER INSTRUCTION MANUAL TABLE OF CONTENTS ...
Page 58: ...3 10 PQMII POWER QUALITY METER INSTRUCTION MANUAL CHAPTER 3 OPERATION ...
Page 84: ...4 26 PQMII POWER QUALITY METER INSTRUCTION MANUAL CHAPTER 4 SOFTWARE ...
Page 170: ...6 32 PQMII POWER QUALITY METER INSTRUCTION MANUAL CHAPTER 6 MONITORING ...
Page 196: ...7 26 PQMII POWER QUALITY METER INSTRUCTION MANUAL CHAPTER 7 APPLICATIONS ...
Page 198: ...8 2 PQMII POWER QUALITY METER INSTRUCTION MANUAL CHAPTER 8 WARRANTY ...
Page 208: ...A 10 PQMII POWER QUALITY METER INSTRUCTION MANUAL APPENDIX A ...
Page 216: ...B VIII PQM POWER QUALITY METER INSTRUCTION MANUAL CHAPTER B INDEX ...