# Meters (Certification) Regulations (Northern Ireland) 1998, Paragraph 10: Insulation property test

Extent: N.I.

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 Quantitles
Reference Value
Tolerance
Ambient temperature
Reference temperature or, if not indicated, 23°C.
>15°C to <30°C ±3°
Meter Position
Vertical
±1.5%
Voltage
Reference voltage
±0.5%
Frequency
Reference frequency 50Hz
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 Number and 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 Numbers 4 and 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 and polyphase
Balanced
2 (intermediate)
1
Ib or 125% Ib
Any load between 25%-75% of the value specified for Test Number 1
Single and polyphase
Balanced
3 (low)
1
5% Ib
1,67% (Note 2)
5%
5%
Single and polyphase
Balanced
4 (inductive)
0.5 (Note 3)
Ib or Imax
100%
The same value selected for Test Number 1
Single and polyphase
Balanced
5 (element)
1
Ib
100%
The same value selected for Test Number 1
Polyphase
One phase loaded in turn
6 (inductive) (element)
0.5 (Note 3)
Ib
100%
The same value selected for Test Number 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 and polyphase
Balanced

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Source: https://www.legislation.gov.uk/nisr/1998/444/schedule/1/paragraph/10 (the official version)
Page: https://openlegislation.uk/meters-certification-regulations-northern-ireland-1998/schedule-1/paragraph-10
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.