Back-up Power Metering

There are quite a few apartment societies who have not made provisioning of metering back-up supply. These societies include the societies who receive bulk power from state utility and also the societies who do not receive bulk power and only distribute back-up power. It is important for these societies to meter the back-up power and bill the same to the resident on the metered consumption. Let us first look at the societies which receive bulk power from state utility and distribute grid power as well as back-up power to the residents.

Such societies do not provision for back-up metering either because dual source energy meters were not available when these societies were built or the societies made provision of back-up power at later point of time. These societies need to consider replacing the existing single source energy meters with dual source energy meters and start metering the back-up power.

Before we proceed further, let us understand the term single source energy meter and dual source energy meter. A dual source energy meter has two consumption registers – one for grid supply and the other for back-up supply. It normally has a provision for back-up power supply signal to the meter (this signal itself could be a DC supply signal or Ac supply signal). When the back-up power is on, the back-up supply signal makes the back-up consumption register on in the dual source energy meter. Thus a dual source energy meter has two meter values at the beginning and end of the month – one for the grid power supply and one for the back-up power supply.

So the question is how this dual source power supply metering is enabled. The society need to replace single source energy meters by suitable dual source energy meters and also make a provision to lay down a signal wire from the back-up power control panel to each meter. It is recommended to lay down an AC power signal wire rather than DC signal wire.

There are however quite a few value proposition which a society can enable for such a project. Some of these value propositions are as follows:

(a)    Society can select the meters which given additional parameters about the meters such as voltage, current, meter readings, power , apparent power, maximum demand, frequency, power factor etc.

(b)   The dual source energy meters are electronic meters and provide for better display as well as archival and access to historical data

(c)    Society can also consider putting load control limits in these meters. More over the load control limits can be set up separately for grid power as well as for back-up power. For example, the grid power limit can be set to 8 kW and back-up power load limit can be set as 4 kW. These values can be set at any time.

(d)   The societies should also consider putting a two way communication mechanism with the meter. This communication can help a society to get the meter consumption data and other data remotely online (say at hourly, daily or monthly frequencies).

(e)   The communication with the meter can also help a society to set the load limits remotely.

(f)     Once the communication is available, the residents themselves can actually see the data remotely.

Of course, these value propositions require a thorough selection and design of infrastructure, meters, communication system and very importantly a software application which can provide the data to the residents.


Please share your experiences for such a system. For any support for design, selection or implementation of such a system, please reach out to us at This email address is being protected from spambots. You need JavaScript enabled to view it.

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