One of the many technical and metrology requirements for obtaining pattern approval and verification from The National Measurement Institute (NMI) for any active-energy electricity meter to be used for trade is for the energy meter to pass the 12KV impulse test. This stringent requirement places further design challenges especially when the energy metering is designed in a compact case. These requirements apply to all watt-hour meters used for single phase or three phase (polyphase) installations.

Impulse Voltage test are per IEC/AS 62052.11 and SP-Method 1618, specified values for impulse voltage and stored energy come from SP-Method 1618 (Impulse Voltage 12KV +0%, -15%) (Stored Energy 9.0J +/- 1.0J) these values are higher than values per IEC/AS62052.11.

SATEC (Australia) has overcome many barriers in obtaining NMI approval for their Din Rail Energy Meters, setting the standards in NMI metering for compact metering designs. Installations for Commercial Buildings where multiple tenant or sub-metering is required must now be a NMI approved meter where electricity billing for trade applies.

Find out more about the NMI Approved EM133 Smart Energy Meter.