A Smarter Way to Handle DG Metering in Multipoint DISCOM Connections

If you’ve worked on the electrical specification for a large residential society in the last five years, you’ve almost certainly dealt with this scenario: the DISCOM installs individual smart meters at every flat. The builder or MEP consultant separately specs an automatic changeover unit at each metering point to handle DG backup. Two devices per flat, two vendors, two line items in the BOM.

It works. But it is not efficient — and it creates three distinct problems that surface long after the project is handed over.

This article explains exactly why multipoint DISCOM connections create DG metering challenges, what those challenges cost societies and their residents, and how a single integrated device is now solving all three problems across housing projects in Delhi NCR.

What Is a Multipoint DISCOM Connection — and Why Does It Matter for DG?

In a conventional bulk-supply residential society, the utility (DISCOM) meters electricity at a single point — typically at the main feeder — and the society handles internal billing itself.

In a multipoint DISCOM connection, the utility installs individual smart meters at each residential unit. Every flat is a direct consumer of the grid. There is no internal energy pooling. This setup is increasingly common in new residential developments across Delhi NCR, Haryana, and other states where regulators are pushing for direct utility billing to eliminate pilferage and improve collection efficiency.

This is, on the face of it, a clean system. But it creates specific and underappreciated problems the moment the society adds a DG set to the mix.

The Three Problems That Emerge When DG Enters a Multipoint Setup

01. No Automatic Switchover

When mains power fails in a society with individual DISCOM meters, each flat needs to switch from grid supply to the DG/inverter backup. In a centralised system, this can be handled at a single point. In a multipoint setup, the switchover needs to happen at each metering point individually.

Without an automatic changeover mechanism at each flat’s metering point, someone has to manually intervene — either the resident switches their own supply, or maintenance staff work through every flat in the building. In a 100-unit or 200-unit society, this means:

• Residents experience extended power interruptions while waiting for manual switching
• Maintenance staff are repeatedly called out during mains failures, including late at night
• DG supply goes to waste for the time it takes to complete manual switching across all units

02. No Source-Wise Billing — DG Consumption Cannot Be Separated

The individual DISCOM smart meters installed at each flat measure total energy consumption. They are designed for grid supply only. When mains fails and the flat switches to DG, these DISCOM meters either stop recording or continue recording incorrectly — there is no mechanism to separate grid kWh from DG kWh.

Some societies install a separate DG-side smart meter at each flat to capture DG consumption independently. This solves the billing accuracy problem — but only partially. The RWA still needs to manually correlate readings across two meters per flat, and the administrative burden of running two separate metering systems adds up quickly.

Without reliable source-wise metering, the society must use estimates, averages, or flat-rate DG charges to recover DG running costs from residents. Residents dispute these charges. Committees spend hours every month resolving complaints. In many societies, this becomes a source of ongoing governance conflict between residents and the facility team.

03. Extra Cost: Changeover Unit + Wiring Per Flat Multiplies Across the Entire Society

This is the most consequential problem from a project economics standpoint — and the one that is most consistently underestimated at the specification stage.

To solve Problem 1 (no automatic switchover), most societies procure a separate Automatic Changeover Unit per flat. To solve Problem 2 (no DG billing), they procure a separate DG-side smart meter per flat. The result: three devices per metering point — the DISCOM smart meter, the changeover unit, and a DG smart meter.

The changeover unit alone typically costs between ₹5,000 and ₹15,000 per unit in the market, depending on make and configuration. Now multiply that across a typical society:

And the hardware cost is only part of the picture. Each changeover unit requires additional wiring between itself and the DG smart meter. In a high-rise society, this means extra conduit runs, extra cable, and extra installation labour at every single metering point — costs that are rarely captured accurately in early project estimates and almost always surface as overruns during execution.

For a 1,000-unit society, the changeover hardware and associated wiring cost can add ₹50–70 Lakh to the project — for a problem that a better-specified meter could eliminate entirely.

Why the Conventional Approach Falls Short

The standard industry response to these three problems is to layer devices: smart meter for grid, changeover unit for switching, second smart meter for DG. Each device solves one problem in isolation. Together, they create a system that is expensive to procure, complex to install, and costly to maintain — with three vendors, three sets of documentation, and three failure points at every flat.

Each problem is solved. The system as a whole is not.

The PES-ACCL: One Device That Solves All Three Problems

The PES-ACCL is a Single-Phase Smart Meter with inbuilt Automatic Changeover — one device that eliminates the need for a separate changeover unit and the additional DG smart meter entirely.

The automatic changeover is built into the meter itself. The moment mains fails, the PES-ACCL switches to DG supply — and simultaneously begins recording DG consumption separately in the same device. When mains is restored, it switches back to grid. No second device. No extra wiring between changeover and DG meter.

⚡ Automatic Source Switching — Problem 1 Solved

The moment mains fails, the meter switches the flat to DG supply instantly. No manual intervention, no maintenance call, no resident waiting. When mains is restored, it switches back automatically.

📊 Source-wise Energy Recording — Problem 2 Solved

DG kWh are recorded separately within the same meter. The facility team gets clean, auditable data on exactly how much each flat consumed from DG source. DG billing becomes accurate and defensible. Disputes are resolved before they start.

💰 Changeover Cost Eliminated — Problem 3 Solved

No separate changeover unit required. No extra wiring between changeover and DG meter. For a 1,000-unit society, this directly eliminates the ₹50–70 Lakh market cost of standalone changeover hardware — before accounting for installation labour savings.

🛡️ Generator Protection

A configurable current limiter prevents overload during DG operation — extending generator life and reducing DG maintenance costs.

🕒 Complete Event Logging

Every mains failure, DG start, changeover, and restoration event is timestamped and stored — a full audit trail for the maintenance team, without manual logs.

📡 Remote Monitoring

Via GPRS, NB-IoT, or Wi-Fi, the facility team views live supply status, monitors consumption by DG source, accesses online billing, and receives instant alerts — without a site visit for every mains failure event.

What This Means for Your BOM

For builders and MEP consultants specifying a multipoint society project, the implication is direct.

Every metering point that previously required two extra devices for DG monitoring — a changeover unit and a DG smart meter — is now a single line item. The PES-ACCL fulfils both specifications in one device.

This reduces per-unit equipment cost, eliminates the changeover-to-DG-meter wiring run at every flat, compresses installation time, and removes an entire vendor category from your project coordination.

Already Deployed in Delhi NCR

The PES-ACCL is not a concept. It is in active use across housing society projects in Delhi NCR. PES Electrical has been manufacturing smart metering solutions since 2012, with over 1,22,700 active metering points under operation and more than ₹2,092 crore in billing managed through our systems. We believe in solving real problems.

Supply, installation, and Annual Maintenance Contracts are available across India.

Conclusion

Multipoint DISCOM connections bring accountability and transparency to residential energy billing. But they shift the complexity of DG management to the individual metering point — and the conventional three-device approach addresses switching and billing only by multiplying hardware cost and installation complexity at every flat.

The right infrastructure choice integrates all three functions. A single device that switches automatically, records DG consumption, and eliminates the standalone changeover unit gives societies the foundation for clean billing, lower maintenance overhead, and better resident relationships — at a materially lower project cost.

If you are currently specifying a housing society project with DG backup and multipoint DISCOM metering, the PES-ACCL is worth including in your evaluation.

Related reading: DG Billing in High-Rise Buildings — The Complete Guide

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