DISCOM Cable Route Survey for BSES, Tata Power-DDL, DHBVN

What is a DISCOM cable route survey?

It is a ground scan along the route of a new distribution cable. It logs the position and depth of 11 kV, 33 kV and LT cables, joints and other utilities. Power distribution companies and their contractors use it to lay new cables without damaging live ones and to plan joints, crossings and substation entries.

Distribution networks are the busiest part of any city's underground. In Delhi, supply was handed to private-public joint ventures in 2002. BSES Rajdhani and BSES Yamuna serve the south, west, east and central parts of the city, and Tata Power-DDL serves the north and north-west. Further south, Faridabad, Gurugram and the rest of southern Haryana get their supply from the state-owned Dakshin Haryana Bijli Vitran Nigam. All of them run large underground HT and LT networks, and all of them keep digging to extend, replace and reinforce them.

When do distribution companies need a cable survey?

Mainly in four situations, each with a different focus.

1. New feeder or cable link. A new 11 kV or 33 kV circuit from a grid substation to load centres. The survey clears its whole route and its crossings.
2. Cable replacement. Old, fault-prone cable being replaced. The survey traces the existing cable, its joints and its neighbours so the new one can follow a safe path.
3. Overhead to underground conversion. Lines being taken off poles in dense areas. The survey checks footpaths and lanes that have never carried HT cable.
4. Substation and RMU works. New ring main units, packaged substations or outgoing feeders, where cables crowd into a small area.

The Government of India launched the Revamped Distribution Sector Scheme in 2021 to cut losses and modernise networks. Alongside its smart metering programme, it has added to this work in many states.

How do we tell live cables from dead ones?

By combining a cable locator with GPR, and by tracing each cable from a known point. Ground penetrating radar (GPR) sends radar pulses into the footpath, and the return signal from a cable or duct shows its position and depth. It cannot say whether current flows in it. The locator does that. Its receiving antenna listens for the field around a live power cable, or for a signal injected at an accessible point, and follows it down the route. Together they let us mark:

• live HT cables, traced from substations or RMUs;
• live LT cables to feeder pillars and service connections;
• dead or abandoned cables, seen on GPR but carrying no signal;
• joints, which often show as a bulge or a change in the reflection.

Our underground cable detection page explains these locating methods in more depth. Abandoned cable is common in older areas, and marking it as such saves crews from treating every target as live.

HT and LT cable survey at a glance

Before excavation, other asset owners should be alerted through Call Before u Dig; our article on what this means on site explains the process.

What else shares the trench with power cables?

Almost everything: water mains, sewers, gas pipes in cities with gas networks, and above all telecom ducts. Telecom operators use the same footpaths and road shoulders, often at similar depths, and their fibre is easy to cut and costly to repair. Optic fibre ducts like these are scanned as on a fibre route; see OFC route GPR survey for the method. For how fibre owners plan their own networks, read what we do: telecom operator projects.

Power cables need clearance from other services for safety and for heat; knowing their real positions is what lets a designer keep it.

Why are older colonies harder to survey?

Because they hold several generations of cable, laid by different crews to different standards, with few records of any of them. Inside one metre of a lane in old Delhi or old Faridabad, there may be a paper-insulated cable abandoned in place and the cable that replaced it. An LT service to each house and the street-light wiring often sit beside them.

Depth varies as much. Cables laid decades ago may sit at a respectable depth, while later service cables were often laid shallow along the house line. Repeated road resurfacing has added layers on top, so a cable that was once shallow can now be deeper than expected. Soil conditions under those layers also change from lane to lane.

In such lanes we tighten the scan spacing, trace every live cable from the nearest feeder pillar, and give each buried object a confidence grade. The drawing then shows the crew where a machine can dig and where only hand digging is safe.

How do we work on live distribution networks?

No cable is touched: we stay inside the contractor's barricades, and on busy roads we often start at dawn or work through the night. Since radar and cable locating never make contact, the scan needs no shutdown. Where a locator signal must be applied to a cable, it is done only at points made available by the network owner's staff.

For DISCOM sites across Delhi NCR, an engineer living nearby is typically on the cable route on order day, and certainly by the business day after. ISO 45001 certification covers how we manage safety.

What does a distribution cable survey cost?

₹24 per metre for standard scanning and ₹32 per metre for L-section, plus GST. The smallest order is ₹50,000 within Delhi NCR and ₹1,00,000 anywhere else in India. On long cable programmes the whole order is discounted: 25% past 100 km, 40% past 500 km and 50% past 1,000 km.

• A 3.2 km 11 kV cable replacement in Faridabad: 3,200 × ₹24 = ₹76,800 plus GST.
• City overhead-to-underground conversion over 40 km: 40,000 × ₹24 = ₹9,60,000 plus GST.
• A 1,100 km state-wide conversion programme: the 50% slab brings the rate to ₹12, so ₹1,32,00,000 plus GST.

The price list sets out the details of GPR survey rates. BSES Rajdhani, BSES Yamuna, Tata Power-DDL and DHBVN have all given us cable route surveys on direct orders. Company names on this page are used only to describe the type of work; all trademarks belong to their owners. Their cable-laying contractors and consultants engage us as well. To plan a route, send your site details.

Frequently asked questions

Can you find the exact location of a cable fault?

Fault location is a separate test done on the cable itself. We map the cable's route and joints, which helps the fault team narrow the search.

Do you need a shutdown to scan?

No. The scan is non-contact. Applying a locator signal to a cable needs the network owner's staff and an accessible point.

Can GPR tell 11 kV from LT cable?

Not by itself. Tracing from substations, RMUs and feeder pillars, plus cable depth and size, makes it clear in most lanes.

How do you plan a road crossing for a new feeder?

We draw an L-section along the bore line. Our service page gives the HDD route survey at a glance.

Do you supply data for the DISCOM's GIS?

Yes, as shapefiles or KMZ alongside the CAD drawings, so the data collection becomes part of the network's underground utility mapping.

Written by Saniya Parveen · Technically reviewed by Rahul Rai · Updated 8 November 2026