Power measurement is an essential activity in situations where the availability of power is crucial or wherever power consumption needs to be monitored. Commonly these measurements either took place ‘upstream’ where the power enters the building or right at the end in the rack where the power is consumed. To fill the gap between ‘metering at the source’ and metering ‘near the user’ we offers a system, to be placed inside the distribution panel. This system will provide a measurement per rack for each feed equivalent to the measurement of an inlet monitored PDU. This offers advantages over an intelligent PDU, however, through the savings achieved by installing a centralized measurement system and the capabilities of retrofitting into an existing running data centre, without a power down, through applying split core current transformers.