Customer feedback has led us to make our 600A/5A CTs for billing use cases yellow in colour to clearly differentiate them from the standard 600A/100mA monitoring CTs, which are black.
Customers using the transformer-connected version of our 3-phase solution bundle (Auditor 6M+One) - for billing use cases, where NMI pattern-approved metering is required - will notice that the special 600A/5A billing CTs we supply are now coloured yellow.
Previously they were black, but that made them more difficult to tell apart from the standard black-coloured 600A/100mA CTs used for performance monitoring of larger-sized circuits.
Now it's simple.
If the CTs are yellow, they are for billing data from circuits >100 amps and <600 amps, and should be attached to the CET brand NMI pattern-approved interval meter (e.g., PMC-340-BB) that is included in the Auditor 6M+One bundle.
Never connect the Orange 600A/5A billing CTs to the Auditor as the 5A secondary current of the billing CTs is likely to damage the Auditor.
The Orange 600A/5A CTs are to be connected to CT systems CET meters such as PMC-340-BB
If they are black, don't use them for use cases where approved billing data is required (such as landlord charging of electricity, solar PPAs and embedded networks).