Wiring standards

1
Wiring standards

• Single phase, 2-wire 120V or 220V
• Single phase, 3-wire
• 220V between phases 110V between phase-neutral
• Three phases, 3-wire
• No neutral 220V between phases
• Three phases, 4-wire
• 220V between phase-neutral 380V phase-phase

2
Fault Tolerant Energy MeteringAD7751 - monitor
phase and neutral currents
3
Anti-Tamper 2 wire, 1f Meter Example AD7751
1f, Real Pwr, anti-pilfer, Motor Drive
Neutral
Input Side
Load Side
Phase
Fault Detection LED
ac to dcPower Supply
5V
Residential Outllets
AD7751
IPhasegtINeut
IPhase
10011...
ADC1A
PGA
11100...
INeut
11100...
10110...
Digital-to- Frequency
X
Line VoltageStepdown
ADC1B
PGA
IPhaseltINeut
Digital Comparator
V
11110...
ADC2
GainCalibration
ReversePolarity LED
CalibrationLED
Note Digital Comparator Selects gt of IPhase or
INeutral
4
Basic 2 wire, 1f Meter Example AD7750/5 1 f,
Real Pwr, Motor Drive output
Neutral
Load Side
Input Side
Phase
ac to dcPower Supply
5V
Residential Outllet
AD7750/5
101011...
PGA
ADC1
Digital-to- Frequency
1101..
Line VoltageStepdown
X
111001...
ADC2
CalibrationLED
GainCalibration
ReversePolarity LED
5
ADE7756/3 Processor based Meter Example(remote
reading or multi-tariff billing)
Neutral
Load Side
Input Side
Phase
ac to dcPower Supply
5V
Residential Outllet
ADE7756/3
1011...
PGA
ADC1
Registers Serial Interface
1101..
MCU LCD Driver
X
1101...
ADC2
Calibration
DTF
LCD Display
CalibrationLED