5 Annex. Meter Forms

The service type determines what meter form is being implemented and how the Metrology DSP core interprets and processes the ADC values.

Table 5-1. Service Types
TYPEService TypeElementsV inputs [Voltage Channels]#I inputs [Current Channels]P/S
0

Three-phase 4-wire Wye

(3-element)

3P4WY_3E_3V3I33 [v1, v2, v3]3 [i1,i2,i3]P
1

Three-phase 4-wire Delta

(3-element)

3P4WD_3E_3V3I33 [v1, v2, v3]3 [i1,i2,i3]P
2

Three-phase 4-wire Wye

(2-½ element) †1

3P4WY_2p5E_2V3I2 1/22 [v1, v2, v3]3 [i1,i2,i3]P
3

Three-phase 4-wire Delta

(2-element) †2

3P4WD_2E_3V2I23 [v1, v2, v3]2 [i1,i3]P
4

Three-phase 3-wire Delta

(2-element)

3P3WD_2E_2V2I22 [v1, v3]2 [i1,i3]P
5

Two-phase 3-wire Network

(2 element) †3

2P3W_2E_2V2I22 [v1, v3]2 [i1,i3]P
6

Single-phase 3-wire

(1-½ element) †4

1P3W_1p5E_1V2I1 1/21 [v1]2 [i1,i3]P
7

Single-phase 2-wire

(1 element)

1P2W_1E_1V1I11 [v1]1 [i1]P/S
8

Single-phase 3-wire

(1 element) †5

1P3W_1E_2V1I12 [v1, v3]1 [i1]P

The next chapters show the configuration for each Service Type.

†1 For the Three-phase 4-wire Wye 2-½ element meter, any one phase voltage may be selected to be the missing phase, and the missing voltage will be internally imputed from the other 2 phase voltages.

†2 For the Three-phase 4-wire Delta 2 element meter, one current sensor is used to measure the collective current of two phases, (IA-IB). All phase voltages VA, VB and VC are measured.

†3 For the Two-phase 3-wire 2 element meter, three common service types with two separate voltage phases and two separate currents may be metered by this mathematically identical service type. These are commonly known as:
  • Two-phase 3-wire Network (2p3WN)
  • Single-phase 3-wire 2 element (1p3W_2E)
  • Two-phase 5-wire (2p5W) with 2 current sensors each used to measure the collective currents of (IA-IA’) and (IC-IC’)

†4 For the Single-phase 3-wire 1-½ element meter where only one phase-phase voltage, VAC, is measured but 2 current elements are measured.

†5 For the Single-phase 3-wire 1 element meter where two individual phase voltages, VA & VC, are measured but only one current element is measured.

METER_TYPE contains all the possibilities for the Service Type available and their configurations.

Figure 5-1. Meter Forms Summary