Multi-function metering is an essential part of any Low Voltage Switchboard and is a vital part of any specification, it's important to get it right when selecting to ensure a cost effective and appropriate solution for your installation.

Typically and broadly speaking there are 4 categories:

 

Basic Energy Metering

Basic Multi-Function Metering

Intermediate Metering

Advanced Metering

 

Basic Energy Metering

A typical meter of this solution is designed to meter one thing, KWH's, that is pretty much everything you will get out of this solution, however, due to the advancement in technology I would suggest there is little difference in price between a more commonly know KWH meter and a Basic Multi-Function Meter. Therefore for a little/no extra cost, the added functionality is a definite bonus.

 

Basic Multi-Function Metering

This is a typical step up from the previous, giving much more functionality and scope of readings of your supply, ranging from:

Current, Voltage, Frequency, Power, Power Factor, Harmonics, and much more dependent upon the particular selection. 

Such meters are of Socomec Diris A20 Meters or the Schneider PM 5000 range.

 

Intermediate Metering

The price increase anyone? This is where the price starts to creep up quite steeply really, essentially incorporating all the basic functionality of the Basic Multi-Function Meter, however, introducing an enhanced power quality monitoring and therefore improving the accuracy the depth and the precision of its operation. 

Such meters are of Schneider PM 8000 range.

 

It is worth getting a comparison chart to understand the differences here to fully understand what you need and what is on offer. Typically I would advise for most requirements Basic Multi-Function Meters for outgoing ways and either a top end basic meter or intermediate meter for the main incomer, but again completely down to what is required to be monitored.

 

Advanced Metering

The daddy meters, you must have a pretty good reason to want to monitor to this level and in most cases a metering specialist to your beacon call to fully understand just what these machines will show you. Here we are introducing waveform capture, fast Fourier Transfer and a whole range of mediums for optimal management of your electrical installation. This is really only used on Low Voltage Switchgear in very particular applications and is quite honestly very very expensive. We are talking car price expensive. Again its worth getting a comparison chart to understand what each meter does within this range but more importantly an expert to help understand just what these units offer you. 
This is really only for very particular applications and is used very rarely, however it's worth seeking a professional if needed if these are required.

Such meters are typical of the Schneider ION range.

 

Typical Metering Protocols

Communication is quite obviously massive, but commonly meters talk in two languages and if you are still using 'Pulsed' its time to change in my opinion.

 

1) Pulsed Output (Digital)

2) RS485 Modbus Comms

 

Pulse is commonly completed by twin pair wired to each meter and is 100% outdated now, taken over by Modbus, giving the functionality to daisy chain the meters together (commonly up to 32) to a single output. Much easier, faster, cheaper and just all round better solution, anyway I am sure you get my point here. 
There are other ways of communication but chances are its Modbus as is common in the metering industry, however this can be converted and commonly is, typically to Modbus TCP - means over ethernet which is gathering pace in the industry and to me is a no-brainer for complete EMS/BMS monitoring of your complete switchboard via one ethernet output.