The short answer
Electrical inspector (CEIG/CEI) approval is the state electrical safety sign-off required before most C&I rooftop solar plants above state-set thresholds (10–100 kW for LT; all HT connections in every state) can be energised. It is a separate statutory gate from DISCOM net-metering approval, with its own drawing pack — SLD, earthing (IS 3043), lightning protection (IS/IEC 62305), protection relay settings, and equipment certifications — and it takes 2–12 weeks depending on the state. Missing it blocks energisation and net-metering agreements.
TL;DR: CEIG approval is the electrical-safety gate (separate from the DISCOM connection file). State LT thresholds vary (10–100 kW; Telangana asks for CEIG above 75 kW; HT always requires it). The file is a drawing pack: IS-format SLD, earthing per IS 3043, lightning protection per IS/IEC 62305, equipment cut sheets, licensed contractor sign-off. Timelines run 2–12 weeks; HT adds protection-relay documentation. File it in parallel with the DISCOM application, with a named owner and diary dates.
CEIG vs DISCOM: two files, two authorities
Two different offices, two different jobs:
- CEIG (Chief Electrical Inspector to the Government; some states style it CEI) is the state electrical safety authority operating under the CEA's Measures Relating to Safety and Electric Supply Regulations, 2023, which replaced the Indian Electricity Rules 1956 framework. It certifies the installation is safe to energise.
- DISCOM grants connectivity and net-metering; its concern is grid compatibility (metering, protection coordination, reverse power limits). The DISCOM requires the CEIG certificate as an attachment in most states.
Plan them in parallel — not sequentially — because inspector timelines are on the critical path. A 100–500 kW rooftop runs 8–14 weeks site-to-energisation on a clean project; HT and inspector delays stretch that to 4–6 months.
When is CEIG approval required? The state threshold question
There is no single national kW number. States set the cut-off by kW or voltage, and it changes — confirm the current rule with the state inspectorate per project. Illustrative state lines:
| State | LT threshold (approx.) | Notes |
|---|---|---|
| Gujarat | ~10 kW (among the lowest lines) | Online portal, 2–4 weeks |
| Delhi, UP, Karnataka, Maharashtra | ~10 kW | District offices; 4–10 weeks |
| Tamil Nadu | ~50 kW | Physical submission, 8–12 weeks |
| Telangana | ~75 kW (per TGSPDCL's solar FAQ; self-certification below) | — |
| Rajasthan | ~100 kW for LT; all HT | RRVPNL-format SLDs; 6–8 weeks |
| All HT connections (11 kV+) | Mandatory in every state | Protection relay panel + settings documentation |
For C&I rooftop plants of 100–500 kW, assume CEIG applies in most states. The CEA Safety Regulations 2023 also put central/UT sites above 500 kVA and >11 kV under the CEA inspectorate — the state inspectorate handles what a C&I buyer actually meets.
The drawing pack: what the inspector actually reviews
The CEIG file is a drawing pack, not a form. The standard set:
- Single-line diagram (SLD) — IS symbology, showing DC side (strings → combiner/inverter), AC side (inverter → metering → grid point of interconnection), protection relays (OVR/UVR/OFR/UFR/EFR per DISCOM grid code), earthing and the bidirectional meter. It must match the equipment actually procured.
- Layout/general arrangement — module layout, cable routing, equipment locations, isolation points.
- Earthing design per IS 3043 — pits, conductor sizing, equipotential bonding; target earth resistance ≤5 Ω (≤1 Ω for HV).
- Lightning protection per IS 16942 / IEC 62305 — air terminals, down conductors, SPDs (Class B at MDB, Class C at inverter input).
- Protection settings — inverter trip parameters, relay pickups, anti-islanding values the HT desk can read.
- Equipment certifications — ALMM-listed modules, BIS-certified inverters, IS 694 cabling.
- Test sheets and photos — insulation, polarity, string and earth tests matching the SLD.
- Licensed electrical contractor/engineer sign-off recognized by that state's inspectorate (a Gujarat-recognized license is not valid in Tamil Nadu).
Process, timelines and rejection causes
Typical sequence: freeze the design → prepare the drawing pack → submit to the state inspectorate (portal or physical) → inspection visit for medium/large systems → approval certificate → energisation and net-metering agreement.
| Stage | Typical timeline |
|---|---|
| Drawing pack preparation | 1–2 weeks |
| State review + inspection | 2–6 weeks (state-dependent) |
| HT additions (protection coordination, transformer docs) | +2–6 weeks |
| End-to-end (clean LT site) | ~4–6 weeks total |
| End-to-end (HT sites) | 4–6 months |
The recurring rejection causes, so you can pre-empt them:
- SLD doesn't match the equipment that actually arrived (freeze drawings before procurement).
- Non-IS symbology, missing relay specifications, wrong signatory credentials.
- Missing earthing calculation sheets or structural certificate.
- Treating the inspector visit as a post-construction surprise — book the inspection when structure work starts, not after energisation readiness.
For the DISCOM side of the same project, see our solar net metering application process and the industrial solar feasibility checklist.
State-by-state notes for Sun Wave's markets
- Haryana: district electrical inspector processing for LT; HT plants need protection documentation; plan CEIG alongside the DHBVN/UHBVN net-metering application — see the DHBVN net metering guide.
- UP (incl. Ghaziabad, Lucknow, Noida belt): district CEIG offices, physical submissions, 6–10 weeks; trade/factory licence mandatory for industrial connections. See the UPPCL/UPERC guide.
- Rajasthan: RVPN-format SLD for HT; 45–75 day HT DISCOM timelines; LT threshold around 100 kW. See the Rajasthan net metering guide.
- Delhi: DEI/DERC-adjacent process; combine with DERC net metering — see the Delhi net metering guide.
- West Bengal: inspector approval precedes licensee energisation; WBERC prosumer rules require anti-islanding compliance. See the West Bengal industrial solar guide.
Frequently Asked Questions
What is CEIG approval for solar in India?
CEIG (Chief Electrical Inspector to the Government) approval is the state electrical inspectorate's safety sign-off for grid-connected solar above the state's capacity threshold — commonly 10 kW for LT and always for HT connections. It certifies the SLD, earthing, lightning protection and protection systems against CEA Safety Regulations 2023, and is required before the DISCOM completes net metering and energisation.
At what capacity does a factory need CEIG approval?
State-specific: ~10 kW in most states, ~50 kW in Tamil Nadu, ~75 kW in Telangana (self-certification allowed below it), ~100 kW in Rajasthan for LT — and all HT (11 kV+) connections in every state require it. Above 500 kVA at central/UT jurisdiction, the CEA inspectorate applies. Verify the current cut-off with your state inspectorate; thresholds change.
What documents are needed for CEIG approval?
The standard pack: IS-format SLD matching installed equipment, layout/GA drawing, earthing design per IS 3043, lightning protection per IS/IEC 62305, SPD plan, protection relay settings (HT), equipment datasheets (ALMM modules, BIS inverters, IS 694 cables), structural certificate, sanctioned-load proof and licensed-contractor sign-off, plus test sheets and photos for medium/large systems.
How long does CEIG approval take?
Preparation 1–2 weeks plus state review of 2–6 weeks typically — 2–4 weeks in online-portal states, up to 8–12 weeks in manual-process states. HT connections run longer because of protection-coordination documentation. File in parallel with the DISCOM application; treat it as a named project stage with an owner.
Can you energise a solar plant without CEIG approval?
No. Energising above the state threshold without inspector approval is unlawful; DISCOMs will not complete net metering, and non-compliance risks disconnection and penalties. Below the threshold, some states allow licensed-contractor self-certification — verify the current rule for your capacity and voltage.
Sources
- CEA (Measures Relating to Safety and Electric Supply) Regulations, 2023 — the statutory frame replacing the Indian Electricity Rules 1956 framework.
- CEA Connectivity Regulations, 2019 — interconnection framework for grid-connected generation.
- State electrical inspectorate rules and published DISCOM FAQs: TGSPDCL solar FAQ (CEIG above 75 kW, self-certification below), TANGEDCO (≥50 kW), Rajasthan RVPN (LT threshold ~100 kW), Gujarat/Maharashtra/Karnataka/Delhi (~10 kW).
- State DISCOM process timelines and format requirements (Gujarat online portal; TN 8–12 weeks; Rajasthan RVPN format; UP district offices), as documented in Indian EPC process guides, 2025-26.
- IS standards: IS 3043 (earthing), IS 16942/IEC 62305 (lightning protection), IS 694 (cables), IS 14286 (modules), IS 16221/16170 (inverters).
Explore Sun Wave's solar solutions
Sun Wave handles statutory approvals end-to-end — CEIG/electrical inspector filings, DISCOM net-metering, and safety compliance per IS codes — for C&I rooftop plants across Delhi-NCR, Haryana, UP, Rajasthan and West Bengal. See our project execution and feasibility checklist guides, or talk to our team.
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