by admin admin

The History of Kwh Metering & Leviton Submeters Today
By: Ken Freemen (SubMeter Product Specialist)


A defining achievement for our world has been the ability to generate large amounts of electricity and transmit that power over long distances; an achievement that was not and is not without cost.
Cost? Yes, cost! And cost has always been paid for with the ability to measure electricity as its being consumed. Is it a stretch to wonder if we would have been enjoying what electricity means to our very lives if there had never been a way to measure the cost of producing it?
Ahhh, the kwh meter! It’s the method whereby consumption of electricity has, and always will be measured. The kwh meter uses current transformers to detect how much electricity is passing through the meter; aka, being consumed. This applies to whomever and whatever is using the electricity.

The utility generates the electricity and sends it over wires to any given point for consumption. Simple.

And based upon how much the meter measures as having been consumed, a bill is generated. Ahh, the monthly electric bill!

How does sub-metering enter the picture? First, keep this in mind: A meter is a meter is a meter! The only difference between a sub-meter and a ‘meter’ that’s mounted on residences and businesses by the utility is……. ‘Who owns the meter’?

Enter the ‘Sub-meter’
A sub-meter is a meter that measures consumption of electricity ‘inside’ of the utility meter and can be installed to measure any given point whether that be the panel serving a tenant or even individual circuits within an electrical panel. The owner of the sub-meter can use the consumption information recorded by the meter to recover costs or to make decisions that may reduce consumption at that point.

Why the Need for Sub-metering?
Although it’s always been possible to meter consumption ‘inside’ the utility meter, the desire and the need to sub-meter began to grow in the early 1980’s and is directly related to dramatically rising utility costs. With a rise in costs, the need for ‘accountability’ grew with it, to identify who………or what was using the electricity and when necessary to recover those costs.
If a meter is a meter is a meter, why aren’t the meters on the side of the building used for sub-metering purposes? Quite simply, the design of the typical utility meter doesn’t lend itself to be efficiently and effectively used for ‘sub-metering’ purposes. Which begs the question, ‘What makes a sub-meter different?’

Current Transformers Make the Difference
Utility type meters utilize internal current transformers which inhibits its use beyond that of metering at the service entrance to a building.
Sub-meters utilize external current transformers which means that the current transformers can be installed at any given point and the meter itself can be mounted in a remote location.

Leviton Acquires Integrated Metering Systems
Delivers revenue grade energy management metering and supports the LEED Certification process

November 30, 2010, Leviton Manufacturing Company, the leader in electrical wiring devices and lighting energy management systems, today announced the acquisition of Integrated Metering Systems, a leading manufacturer of revenue-grade sub-metering products. Combined with Leviton’s worldwide distribution and sales channels, we can now offer solutions that meet all requirements for measurement and verification issues such as smart metering, load management and LEED rating achievement.

About IMS
Founded in 1989, IMS has been a pioneer in the manufacture of sub-metering systems that quantify energy usage for a multitude of applications, such as tenant billing, energy management, solar PV production, cost accounting and a wide array of other applications to control and manage energy usage and costs. IMS meters meet the additional needs of the marketplace by being small in size and can be offered in larger cabinets housing as many as 19 meters.

2015 Going Forward
Today, not only does Leviton’s Metering Solutions provide the marketplace with the most basic needs for monitoring electrical consumption but also products and Automatic Meter Reading capabilities that answer the most stringent requirements for data acquisition and analysis. And, while using an open protocol, Leviton’s metering products interface to all known Building Automation Systems with ease.