Metering in Mayfair

Compliance with the European Measuring Instruments Directive was just one of the benefits of an installation of panel mount meters in a prestigious London address

Landlord, managers and tenants of a prestige office complex in London's Mayfair are reckoned to be the first in Europe to benefit from metering and billing compliant with the European Measuring Instruments Directive (MID). The owners of One Curzon Street have installed Carlo Gavazzi's EM24 meters - the first of their kind to earn full MID Certification from PTB in Germany.

One Curzon Street

One Curzon Street is one of many high-class buildings in Mayfair Commercial's portfolio, a company owned by the Abu Dhabi Royal Family. Mayfair's managing agents GVA Grimley look after around 30 tenant meters and 11 landlord supply meters in the building, located in client premises and communal areas.

When looking to replace existing meters with a MID-Certified solution, they turned to SHM Communications, a Hampshire-based company specializing in meters and systems for energy measurement, power management and tenant billing.

SHM recommended Carlo Gavazzi's EM24 DIN Rail Mount MID Certified meters, explained SHM's managing director Peter Hutt: "The owners wanted nothing but the best, and the EM24 DIN-rail meter is available with a 96x96 panel mount kit that, for the first time. allows us to install meters used for billing purposes neatly mounted in a panel".

The EM24 is a single or 3-phase energy analyser and kWh & kvarh meter, with dual pulse output. Its MID Class B rating is equivalent to the EN62053-21 Class 1. A joystick selects display of watts, var, voltage, current, power factor, frequency, demand and phase sequence. Digital outputs can be used either for pulses proportional to the active and reactive energy being measured, or for alarm outputs. Alternatively an RS485 communication port and three digital inputs are available as options.

The unit comes in a DIN rail mount casing offering IP50 (front) protection against moisture and dust ingress. It can be connected directly to supplies up to 65A, as well as to external current or potential transformers.

Installation at One Curzon Street of over 40 meters was completed in less than one day

SHM was able to meet a tight installation deadline thanks to its close relationship with Carlo Gavazzi. They we able to procure the recently introduced meters on a fast-track order that secured the 40-plus units from among the earliest production runs. Four two-man teams completed the installation within a day, averaging one meter per installer per hour. "This is quite an achievement, when it is considered that each meter requires making and testing no less than 12 connections." according to Peter Hutt.

Labels and anti-tamper seals were fitted subsequently to ensure 100-percent MID certification. For the future, interfacing to automated billing systems would be a straightforward operation thanks to built-in functionality in the meters.

The MID Directive explained

The MID Directive is a recent piece of EU legislation for the certification of certain types of measuring instruments. Its Annexe MI-003 supersedes all national metering approvals pertaining to electricity meters, such as Ofgem in the UK and since October 2006 all electricity meters used for billing purposes must either be MID certified or Ofgem approved for sites under 100kW. There is a grace period during which Ofgem meters are allowed, but soon these will all be superseded by designs with MID certification.

This is based on an article that appeared in Energy In Buildings & Industry, January 2008.