Paragraph 10 Insulation property test
Each meter shall be tested to demonstrate that the insulation of the meter is of a sufficient standard to enable the meter to operate safely and correctly in the conditions in which it could reasonably be expected to be installed and operated.
TABLE 1
| Influence quantities | Reference value | Tolerance |
|---|---|---|
| Ambient temperature | Reference temperature or, if not indicated, 23°C. | >15°C to <30°C |
| Meter position | Vertical | ±3° |
| Voltage | Reference voltage | ±1.5% |
| Frequency | Reference frequency 50Hz | ±0.5% |
| Voltage and current waveform | Sinusoidal form | Distortion factor <5% |
| External magnetic induction at the reference frequency (paragraph 5.4) | Zero | Induction value that does not produce a relative error variation of more than& ±0.3% |
TABLE 2
| Test load in terms of marked current | |||||||
|---|---|---|---|---|---|---|---|
| Test No. & load | Power factor | Basic/maximum | Maximum continuous | Long range | Short range | Meter type | Polyphase meter load |
| Note 1 Where a range is given, any value within that inclusive range may be selected. | |||||||
| Note 2 For maximum continuously rated prepayment meters, the low load test value may be twice the value shown. | |||||||
| Note 3 For test no. 4 & 6, the inductive power factor shall be between 0.45 and 0.55 inclusive. | |||||||
| 1 (high) | 1 | Imax | 100% | 100%–200% (Note 1) | 100%–125% (Note 1) | Single & polyphase | Balanced |
| 2 (intermediate) | 1 | Ib or 125%IB | Any load between 25%–75% of the value specified for Test No. 1 | Single & polyphase | Balanced | ||
| 3 (low) | 1 | 5%Ib | 1.67% (note 2) | 5% | 5% | Single & polyphase | Balanced |
| 4 (inductive) | 0.5 | Ib or Imax | 100% | The same value selected for Test No. 1 | Single & polyphase | Balanced | |
| 5 (element) | 1 | Ib | 100% | The same value selected for Test No. 1 | Polyphase | One phase loaded in turn | |
| 6 (inductive) (element) | 0.5 | Ib | 100% | The same value selected for Test No. 1 | Polyphase | One phase loaded in turn | |
| 7 (starting-current) | 1 | 0.5%Ib to 1.0%Ib | 0.5% to 1.0% | 0.5% to 1.0% | 0.5% to 1.0% | Single & polyphase | Balanced |