Compliance hub · Last reviewed 1 August 2026
CPCB IV+ and RECD, without the panic
What the norms actually say, who they actually bind, and the retrofit-or-replace arithmetic — written by a company that had to answer these questions for its own 80-set fleet.
The short version
- Buying a new genset up to 800 kW? It must be CPCB IV+ — notified by gazette G.S.R. 804(E) of 3 November 2022, in force for new sets since 1 July 2023, with no exemption for small diesel sets.
- Own existing sets in Delhi-NCR? CAQM Direction No. 76 restricts unretrofit diesel gensets: dual-fuel conversion and/or a CPCB-certified RECD by capacity band, with GRAP-stage usage bans and active sealing of violators.
- Existing sets in Maharashtra, Karnataka or Kerala? These states have their own retrofit regimes — MPCB's circular of 2 June 2023 covers in-use diesel gensets up to 800 kW (compliance window closed 31 December 2023, now enforced through consent conditions); Karnataka's board mandates RECDs on sets of 125 kVA and above; Kerala's board mandated RECD retrofits on in-use sets by circular of 28 September 2024, following a Kerala High Court order.
- No pan-India retrofit mandate as of 1 August 2026 — but the obligations that do exist are regional, real, and already being enforced.
- The decision is arithmetic: retrofit cost vs replacement TCO, per set. We run both numbers in writing.
60-second check
Indicative guidance based on norms as of 1 August 2026. Not legal advice — confirm your site's position with your State Pollution Control Board, or let our audit do it for you.
The standard
Not a sticker — an engineering step-change. Meeting it required genset makers to add the kind of after-treatment trucks adopted years ago, which is why compliant sets carry DEF tanks and why they cost more.
- Notified as gazette G.S.R. 804(E) of 3 Nov 2022; in force for new gensets from 1 July 2023, never deferred
- Covers ALL new diesel gensets up to 800 kW — five power bands, no small-set exemption
- Roughly 90% lower PM and NOx than CPCB II (per Cummins' compliant-range launch)
- Met with electronic common-rail engines plus after-treatment dosing DEF — with an on-board-diagnostics mandate for NOx control
- Factory-certified: Type Approval + Conformity of Production via ARAI, ICAT or IIP — compliance is not site-declared
- Noise unchanged: 75 dB(A) at 1 m for sets up to 1000 kVA, a separate rule that predates and survives CPCB IV+
- New-equipment norms only — existing installed sets are governed by the retrofit regimes below
Two paths to compliant power
Buying a new set
Every new genset up to 800 kW must be CPCB IV+. The Cummins CPCB IV+ range — 7.5 to 750 kVA — is certified at the factory; above 800 kW a separate MoEFCC regime applies. We supply, install and commission both.
See the Cummins rangeExisting fleet
Register the assets, map each site's actual obligations, then per set: retrofit an RECD, convert, or replace — decided by arithmetic, documented for your auditor.
Book the auditRECD, explained
A Retrofit Emission Control Device bolts after-treatment onto a set built before the standard — cutting particulates typically by 70–90%. We have run this evaluation on client sets, including a 625 kVA Perkins unit, with certified retrofit vendors.
- Fitted to the exhaust; the engine stays as built — CPCB requires ≥70% particulate capture
- Only CPCB-certified devices count — the official vendor list (updated 30 June 2026) names Chakr Innovation, Pi Green, Cummins Technologies and others
- Mandated by region: Delhi-NCR (CAQM Direction 76, by capacity band), Maharashtra (MPCB circular, up to 800 kW in-use), Karnataka (125 kVA+)
- Alternative routes where allowed: dual-fuel conversion (70% gas), or replacement with a CPCB IV+ set
- Cost scales with kVA — often far below replacement
- We assess feasibility per set, with certified vendors, before recommending it
Why act before the letter arrives
Non-compliance doesn't fine you. It switches you off.
This is not theoretical. CAQM has ordered physical sealing of DG sets at non-compliant units — with environmental compensation backdated to October 2023 — and publishes its sealing list continuously, most recently updated July 2026. The November 2025 GRAP revision moved DG restrictions a full stage earlier. In Maharashtra, MPCB now writes the RECD requirement directly into consent-to-operate conditions. The retrofit is always cheaper than the shutdown.
Sources & further reading
Where these statements come from
- Gazette G.S.R. 804(E), 3 Nov 2022 — the CPCB IV+ notification (via CPCB)
- Gazette G.S.R. 436(E), 14 Jun 2023 — supply-window amendment
- PIB, 29 Sep 2023 — CAQM Direction No. 76 schedule for DG sets in Delhi-NCR
- CPCB RECD certification procedure (PCLS/12/2021-22, revised) — ≥70% PM capture
- CPCB list of certified RECD manufacturers (as of 30 Jun 2026)
- MPCB circular, 2 Jun 2023 — RECD for in-use DG sets in Maharashtra (extension to 31 Dec 2023 via circular of 26 Oct 2023)
- KSPCB notification, 25 May 2023 — RECDs mandatory on 125 kVA+ DG sets in Karnataka
- CPCB — 75 dB(A) noise limit for diesel gensets (Schedule I, serial 94)
Reviewed 1 August 2026. Norms in this space move — if you are reading this months later, call us before relying on it. We track these rules because our own fleet lives under them.
Compliance, answered
Frequently asked questions
What is CPCB IV+?
CPCB IV+ is India’s current emission standard for new diesel generator sets, notified by the Ministry of Environment, Forest and Climate Change and enforced through the Central Pollution Control Board. It applies to new gensets up to 800 kW sold since 1 July 2023, and demands drastically lower emissions than the previous CPCB II stage — met with after-treatment such as SCR/DPF and DEF dosing.
Does CPCB IV+ apply to my existing DG set?
No — the gazette applies CPCB IV+ to new engines and gensets only; nothing in G.S.R. 804(E) requires an already-installed set to be retrofitted or replaced. Existing sets are instead governed by regional retrofit regimes: CAQM Direction 76 in Delhi-NCR, MPCB’s state-wide RECD circular in Maharashtra, KSPCB’s 125 kVA+ mandate in Karnataka, and consent-to-operate conditions everywhere.
What is an RECD?
A Retrofit Emission Control Device — an exhaust after-treatment unit fitted to an existing diesel genset to cut particulate emissions, typically by 70–90%. RECDs are the compliance path regulators offer older sets in enforcement zones as an alternative to replacement or dual-fuel conversion.
Is an RECD mandatory for my generator?
It depends on the state. Delhi-NCR: CAQM Direction 76 requires dual-fuel conversion and/or a CPCB-certified RECD by capacity band, with GRAP usage bans for non-compliant sets. Maharashtra: MPCB’s circular of 2 June 2023 requires RECDs on qualifying in-use diesel gensets up to 800 kW — the window closed 31 December 2023 and the requirement now appears in consent conditions. Karnataka: KSPCB mandates RECDs on sets of 125 kVA and above. Elsewhere there is no blanket mandate yet — confirm with your SPCB or book an audit.
What happens if a site ignores this?
Documented enforcement, not hypothetical risk: CAQM has ordered DG sets physically sealed at non-compliant units with environmental compensation backdated to October 2023, and publishes an ongoing sealing list (updated as recently as July 2026). The November 2025 GRAP revision moved DG restrictions a full stage earlier. In Maharashtra the RECD requirement now sits inside consent-to-operate conditions — non-compliance puts the facility’s licence, not just the genset, in question.
Should I retrofit my old set or replace it?
Arithmetic, not ideology: a structurally sound, low-hours set in an enforcement zone usually justifies an RECD; an ageing, fuel-hungry set close to overhaul often makes replacement with a CPCB IV+ unit the cheaper five-year answer. Power Solutions runs both numbers — retrofit cost against replacement TCO — and shows you the workings before you commit.
Can Power Solutions supply CPCB IV+ gensets today?
Yes — as an Associate Dealer of Cummins Powerica: the Cummins CPCB IV+ range from 7.5 to 750 kVA, plus larger sets above 800 kW under the separate MoEFCC regime, supplied, installed and commissioned across Maharashtra, Goa, Karnataka, Kerala and Andhra Pradesh, with CPCB IV+ rental units joining the fleet as it transitions.
What does a compliance audit from Power Solutions cover?
A site-by-site register of your DG assets — make, rating, year, emission stage, running hours — mapped against the rules that actually bind each site, with a written recommendation per set: compliant as-is, retrofit, convert, or replace, each with indicative cost. You get a document you can hand to an auditor or a board.
Reply within 4 working hours. Engineered offer within 24 hours.