This is a 3 phase CT operated kWh meter.
3 x 230 Volts
3 x 5 Amps
In commercial installations more than 100 Amps a CT operated kWh meter is usually fitted, as the cabling becomes to heavy and unpracticable to put direct through the meter.
Current transformers CT's measure the actual current through the main bus bars.
e.g. 200 Amps measured , 5 Amps out from the CT. hence multiplier of X 40
This meter is a two rate single demand meter, made obsolete about 10 years ago when time of use metering was introduced.