Main Content

CT Testing

Metropolis provides flexible low voltage current transformer (LV CT) inspection, testing and certification services to ensure ongoing accuracy and compliance of metering installations as required by the National Electricity Rules.


Current transformers are tested in accordance with AS 60044.1

  • limits of error outlined at 25% of rated burden resistive
  • unity power factor (ie. power factor = 1.0).
  • load test points at 5%, 25% & 100% of rated current
  • extended range load test point as required

Sample testing programs are conducted in accordance with AS/NZS 1199.1-2003 and AS/NZS 2490-1997 to ensure ongoing measurement accuracy across defined current transformer populations by type.

Metropolis comprehensively inspects all current transformers upon become responsible for a metering installation and/or testing.

Details recorded for each current transformer by phase include:

  • Make
  • Type
  • Serial number
  • Accuracy class
  • Available ratios
  • Connected ratios
  • Range
  • Burden
  • Terminal connections
  • Fusing

Comprehensive checks are also completed to verify:

  • primary/secondary ratio
  • burden
  • secondary current comparison, including voltage, current and phase relationships
  • phase rotation
  • ratio application at the meter

Through our access to industry databases Metropolis is able in many cases to verify the year of manufacture to ensure a complete record of current transformers is maintained.

Let us prepare and implement your annual test plan from initial population analysis through to submission of final test results using approved sample testing methodologies.

Commercial Electricity Metering

Commercial Electricity Metering

Metropolis provides a comprehensive range of metering solutions for business, commercial and industrial electricity users. read on Commercial Electricity Metering

Event Messaging

Event Messaging

Metropolis will advise your nominated recipients as critical events affecting electrical system performance or pricing occur. read on Event Messaging

Latest News

All News

Quick Links