SLD preparation · India · as-built single line diagram · AutoCAD · ETAP · SKM · LT to 66 kV
SLD preparation for Indian plants: a field-verified single line diagram, ready for CEIG, audits and arc flash studies.
VB Engineering prepares as-built single line diagrams for operating plants across India. An engineer opens every panel, records every breaker, cable and relay, and issues the SLD in AutoCAD or as a study-ready ETAP or SKM model. Run the free SLD scope check and get a written estimate in two business days.
1,000+ studies21 countriesWorking since 2014AutoCAD, ETAP and SKM
Free SLD scope check · 2 minutes
| The SLD must show | |
|---|---|
| Starting point | |
| Field survey | |
| Sources | |
| You receive |
The check turns your answers into a first scope; it is not an engineering opinion. Send it and a VB engineer returns the written scope and price estimate in two business days. Short form, no phone number.
Trusted on plants that cannot stop
- 0arc flash and power system studies signed off
- 0countries where VB has surveyed and modelled plants
- 0the year VB started work
- 0uses for one SLD: CEIG approval, safety audit and the study
Study counts: VB Engineering project register.
How the free check works
- 1
Six answers, two minutes
Why you need the SLD, your highest voltage, what drawings you have, roughly how many panels, your DG sets or solar, and the output you need.
- 2
An engineer reads it
A VB electrical engineer reads your answers against what your inspector, auditor or study will ask the SLD to show, and plans the survey.
- 3
Estimate in two days
Survey scope, deliverables and a price estimate in writing, ready for your plant head or purchase team.
Who will ask for it
When does a plant in India need an up-to-date single line diagram?
A plant in India needs a current single line diagram whenever it applies to the electrical inspectorate, faces a safety audit or insurer survey, adds a DG set, transformer or solar feeder, or commissions an arc flash or power system study. Each of these starts from the SLD, and each fails if the drawing does not match the panels on site.
| Instrument or event | What it asks of the plant | What the SLD must show | Who will ask for it |
|---|---|---|---|
| CEA (Measures relating to Safety and Electric Supply) Regulations 2023 | Inspection and approval of HT installations, transformers and DG sets; state inspectorate forms ask for the SLD of the installation to be enclosed | Every source, transformer, HT and LT switchgear and protective device, with ratings | The Chief Electrical Inspector (CEIG) or state electrical inspector |
| New DG set, transformer, HT connection or solar addition | Approval before energisation and a revised drawing after it | The new source and how it parallels or changes over with the grid supply | The inspectorate, your DISCOM and your projects team |
| IS 14489:2018 safety audit · insurer risk survey | The electrical section of the audit is checked against the plant's drawings | The installation as it stands today, panel by panel | The safety auditor; your insurer's risk engineer |
| NFPA 70E 205.2 | Where a single-line diagram is provided, it is kept legible and current | Current, legible, matching the gear | Your parent company's EHS audit at multinational plants |
| Arc flash, short circuit or relay coordination study | The study is calculated bus by bus on the SLD | Every bus, cable, breaker and relay with its settings | Your study engineer, and VB before any study it runs |
VB prepares one SLD that serves all of these: drawn to the detail the inspectorate asks for, checked panel by panel for the auditor, and built so it can become an arc flash study model without being redrawn.
Why plants call VB
Is your SLD missing, out of date, or about to be asked for?
Most plants call VB for an SLD for one of five reasons: the drawings are lost or years out of date, an expansion or new DG set changed the system, the inspectorate needs it for approval, an auditor or insurer asked for it, or an arc flash or power system study needs a verified model. VB's survey answers all five with one drawing.
Drawings missing or outdated
The last SLD predates three expansions, exists only on paper, or left with the contractor who built the plant. VB rebuilds it from the panels, not from memory.
Expansion, DG set or solar
A new block, transformer, DG set or rooftop solar feeder changes fault levels and changeover logic. The SLD is redrawn so the change is approved and the protection still works.
CEIG or inspector approval
The application is returned until the enclosed SLD matches the installation. VB draws it to the detail your state inspectorate asks for.
Safety audit or insurer survey
"Electrical drawings not updated" is a common audit finding. A field-verified SLD with a deviation list closes it on one document.
Arc flash or power system study
Fault current and incident energy are calculated on the SLD. VB verifies it first, so the values on your labels are right.
One drawing, every use
The same as-built SLD goes to the inspectorate, the auditor and the study team, so nobody works from a different version.
What VB delivers
What do you receive from VB's SLD preparation?
VB's SLD preparation delivers an as-built single line diagram in AutoCAD, verified panel by panel on site, with a data register of every breaker, cable and relay and a list of every deviation from your old drawings. On request, the same SLD is built as an ETAP or SKM model ready for an arc flash or power system study.
| Included | On request |
|---|---|
| Field survey: each panel opened, nameplates, breaker ratings, CT ratios, cable sizes and relay details captured in ElecTwin, VB's field data app | Thermal imaging of panels during the survey |
| As-built SLD in AutoCAD, DWG and PDF, HT and LT, every source and feeder | The SLD built as an ETAP or SKM PowerTools model |
| Key SLD: the whole site on one sheet, intake to main LT panels | Panel GA drawings and control schematics |
| Data register of every panel, breaker, cable and relay surveyed | Earthing layout drawing |
| Deviation list: every difference from your old drawings, marked on the new SLD | SLD set formatted for your CEIG or inspectorate submission |
The method, stage by stage
- Data request · your old drawings, panel list and any approval letters, collected before the visit so site days go on the panels
- Field survey · every panel opened and photographed inside your working hours or shutdown window, HT gear with your permit-to-work
- Drafting · the as-built SLD drawn in AutoCAD, sources at the top, then HT, transformers, PCCs, MCCs and DBs
- Check · a second VB engineer checks the drawing against the survey photographs and the data register
- Model, if ordered · the same SLD built in ETAP or SKM, ready for short circuit, relay coordination and arc flash
- Issue · DWG, PDF, data register and deviation list
Tool expertise
Which software do VB's arc flash teams work in?
VB has dedicated engineering teams with hands-on expertise in ETAP, SKM PowerTools, CYME, EasyPower, PSS®E and NEPLAN. Your SLD can be built as a model in whichever software your plant or parent company already uses, so the next study starts without a second survey.
Price
How much does SLD preparation cost in India?
SLD preparation in India is priced on the number of panels and buses to survey, the highest voltage on site, the state of your existing drawings, and the output: AutoCAD only, or AutoCAD plus a study-ready ETAP or SKM model. Floor area is a poor guide; the panel count is the work.
| Price driver | Why it moves the price | How VB shows it in your estimate |
|---|---|---|
| Number of panels and buses | Each panel is opened, surveyed, drawn and checked | A rate per panel, by voltage class |
| HT gear (11 kV and above) | Needs a shutdown or permit to open, and relay details to record | HT priced apart from LT |
| Existing drawings | Usable AutoCAD shortens drafting; no drawings means a full rebuild | Stated as an assumption in the scope |
| ETAP or SKM model | The model needs cable lengths, impedances and relay settings, not only the drawing | Its own line, so you can add it later |
| Panel GA, schematics, earthing layout | Separate drawings with their own survey detail | Each priced as its own line |
Run the free SLD scope check above and the written scope and price estimate come back in two business days. If the SLD feeds a study, see how VB prices an arc flash study.
A pharmaceutical formulation plant
How did VB rebuild the SLD of a pharmaceutical plant in South India for its CEIG submission?
At a large pharmaceutical formulation plant in South India, modelled with an 11 kV intake, three DG sets and about 175 panels, VB surveys every panel in six site days and issues an as-built SLD and ETAP model. Modelled result: 41 deviations from the old drawings found, two existing DG sets and the new solar feeder put on the drawing, and the CEIG application re-filed on the verified SLD.
The trigger
The plant added a third DG set and a rooftop solar feeder. The application to the inspectorate was returned because the enclosed SLD, last revised years earlier, did not show the existing DG sets or the new block. The plant also had an arc flash study planned for the next year.
What the survey found
| Finding | Why it matters |
|---|---|
| 41 deviations from the old SLD | Feeders, panels and breakers added in two expansions and never drawn |
| 2 DG sets missing from the drawing | The inspectorate could not see how the DG sets changed over with the grid supply |
| 1 solar feeder not shown | A new source on the LT bus, changing fault levels |
| 9 breaker ratings different from the drawing | Wrong values would have gone into the arc flash study |
| 11 kV relay details unrecorded | Needed for the CEIG submission and for relay coordination |
What VB delivered
VB issued the as-built SLD in AutoCAD with a key SLD for the site, the data register and the deviation list, formatted for the inspectorate submission. The same SLD was built as an ETAP model, so the arc flash study the next year started from a verified network instead of a new survey.
| Measure | Before | After |
|---|---|---|
| Deviations between drawing and site | 41 unknown | 0, all drawn |
| Sources shown on the SLD | Grid only | Grid, 3 DG sets, solar |
| Panels with recorded ratings | Partial | All, in the data register |
| Drawing format | Paper, one revision | AutoCAD and ETAP model |
| Site days for the survey | 6 | |
The application closes on one drawing set: an as-built SLD that matches the panels, a key SLD and a data register the inspector can check. The same drawing becomes the arc flash model, so the plant pays for the survey once.
Why plants choose VB
Why do Indian plants bring VB their single line diagrams?
VB's SLDs are drawn by the engineers who run arc flash and power system studies, so the drawing carries the detail a study needs, not just what a draughtsman sees.
Every panel is opened and photographed. Nothing is copied from an old drawing without being checked on site.
The same SLD serves the inspectorate, the auditor and the study team, so the plant pays for the survey once.
Issued in AutoCAD, and on request in ETAP or SKM, so the drawing can be calculated, not only printed.
Surveys run inside your working hours, and HT gear inside your shutdown window, with your permit-to-work.
You receive a list of what was wrong in the old drawings, which closes the audit finding on its own.
Free, in two business days
What do you get back from the free SLD scope check?
The free SLD scope check returns three things within two business days: a written survey scope for your plant, a price estimate split into survey, drafting and any model or extra drawings, and a timeline built around your CEIG, audit or study date. There is no fee and no sales call.
Written scope and estimate
Panels, voltage levels, sources and deliverables, priced line by line, so you can take one number to your plant head this week.
A timeline to your date
Survey, drafting and issue laid out against your inspectorate filing, audit or study start.
The study path, if you need it
Whether the SLD should be built as an ETAP or SKM model now, so a later arc flash or relay study needs no second survey.
Read more: arc flash studies in India · relay coordination in India · short circuit analysis · power system studies · electrical safety audit · CAD drawing preparation.
Before you ask
Questions plant engineers ask VB about SLD preparation
What is SLD preparation?
SLD preparation is the work of drawing a plant's single line diagram: one drawing that shows how power flows from the utility intake and generators through transformers, switchgear and feeders to every panel and major load. At VB it starts on site. An engineer opens each panel, records ratings, breaker and relay details, and issues an as-built SLD in AutoCAD, and on request as a study-ready ETAP or SKM model.
What is the full form of SLD in electrical engineering?
SLD stands for single line diagram, also called a one-line diagram. It uses a single line to represent all three phases of a circuit, with standard symbols for transformers, breakers, buses, cables and loads, so the whole power system of a plant fits on a few sheets.
What is the difference between an SLD and a wiring diagram?
An SLD shows the power system as a whole: sources, transformers, buses, protective devices and feeders, one line per circuit. A wiring diagram shows the physical connections inside one panel or circuit: terminals, wire numbers and colours. Plants need both, but inspectors, auditors and study engineers ask for the SLD first.
Which documents does a CEIG or electrical inspector approval need, and where does the SLD fit?
Lists vary by state inspectorate, but applications for a new HT installation, transformer, DG set or solar plant usually ask for the single line diagram of the installation, the layout, and equipment test certificates. State inspectorate forms issued under the CEA (Measures relating to Safety and Electric Supply) Regulations 2023 ask for the SLD to be enclosed. VB prepares the SLD to the detail your state portal asks for.
How often should a single line diagram be updated?
Every time the electrical system changes: a new transformer, DG set, solar feeder, panel or relay setting. NFPA 70E 205.2, which multinational plants in India audit to, requires the single-line diagram to be kept legible and current. Common industry guidance adds a full review at least every five years and at each major shutdown.
Why does an arc flash study need an accurate single line diagram?
Because the study is calculated on the SLD. Fault current, protective device clearing time and incident energy are worked out bus by bus from the diagram, so a missing transformer, DG set or feeder gives wrong values on the label. VB verifies the SLD on site before any arc flash, short circuit or relay coordination study is run.
What exactly do I receive from VB's SLD preparation?
An as-built SLD in AutoCAD (DWG and PDF), a data register of every panel, breaker, cable and relay surveyed, and a list of every deviation from your old drawings. On request: the same SLD built as an ETAP or SKM model, a key SLD for the whole site, panel GA drawings, control schematics and earthing layouts.
How much does SLD preparation cost in India?
SLD preparation is priced on the number of panels and buses to survey, the highest voltage on site, whether usable drawings already exist, and whether you need AutoCAD only or a study-ready ETAP or SKM model. Run the free SLD scope check on this page and the written scope and price estimate come back in two business days.
How long does SLD preparation take?
It depends mainly on the panel count and on whether HT gear needs a shutdown to be opened. VB plans the survey inside your working hours or maintenance window, and the written scope states the survey days and the drafting time before you place the order.
Can VB convert our old paper or scanned electrical drawings into AutoCAD?
Yes, but VB does not trace old drawings blindly. Paper and scanned SLDs are used as the starting point, every panel is checked on site, and the AutoCAD drawing is issued as-built with each change from the old drawing listed, so you know what was wrong.
Which standard does VB follow for SLD symbols?
VB draws to IEC 60617 graphical symbols, the series India adopted as IS 12032, or to your company's own drafting standard if your parent company or consultant has one. Voltage levels, ratings and tag numbers follow your plant's existing numbering so the SLD matches the labels on the panels.
What happens after I submit the form?
A VB engineer replies by email inside two business days with the survey scope, what the SLD will cover, the deliverables list and the price estimate. Nobody calls unless you ask. If you need the SLD for a CEIG submission or an audit date, say so on the form and the timeline is built around it.
Your SLD scope and estimate, back in two business days.
Six answers today. A VB engineer returns the survey scope, the deliverables and a price estimate, built around your CEIG, audit or study date. No charge, no call unless you want one.
Get SLD estimatePrefer email? Send your panel count to connect@groupvb.com with "SLD" in the subject line.