RECD Installation Timeline: What to Expect, Start to Finish

“How long is this actually going to take?” is usually the second question anyone asks about RECD installation, right after “how much does it cost?” It’s also the question vendors answer least precisely, because the honest answer depends on your generator’s capacity, whether it’s open or enclosed, how many units you’re fitting, and how quickly your own paperwork and site access come together.

This post gives you a realistic, stage-by-stage timeline, counted down the way you’d actually experience it: from the day you decide to move forward, through the days your generator is physically out of action, to the point where the paperwork is filed and the job is genuinely closed. If you’re trying to schedule this around a compliance deadline, a planned shutdown window, or a facility inspection date, this is the planning reference to work from.

The Short Answer

For a single generator in the common capacity range, expect roughly 18 to 35 days from the day you confirm an order to the day installation and commissioning are complete. Of that window, only 1 to 3 days involve your generator actually being offline. The rest is fabrication time at the vendor’s workshop, happening in parallel with your normal operations.

That range compresses for smaller, simpler jobs and stretches for large-capacity, multi-unit, or enclosed-canopy installations. The rest of this guide breaks down exactly where that time goes and what causes it to move in either direction.

The Timeline at a Glance

Stage	Typical Duration	What’s Happening
Vendor selection and decision	3 to 10 days (varies widely)	Comparing vendors, confirming CPCB approval, getting quotes
Site survey and technical assessment	1 to 3 days	Vendor visits or reviews your generator’s specs, exhaust layout, space
Order confirmation to fabrication start	1 to 2 days	Paperwork, advance payment, technical drawing sign-off
Fabrication	2 to 4 weeks	Custom RECD unit built to your generator’s exhaust dimensions and capacity
Pre-installation site prep	1 to 2 days	Scheduling the shutdown window, arranging site access, safety clearance
Physical installation	1 to 3 days	Exhaust modification, RECD mounting, structural and electrical work
Commissioning and testing	Same day to 1 day after fitting	Test run, backpressure check, initial performance verification
Documentation and certification handover	3 to 10 days after commissioning	Installation certificate, compliance file, CPCB-linked paperwork

Now let’s walk through this the way you’d actually live it, counting down from the decision point.

T-Minus 30 to 21 Days: The Decision Window

This is the part of the timeline entirely within your control, and it’s also the part most people underestimate. Choosing a CPCB-approved vendor, comparing capacity-specific quotes, and confirming a manufacturer’s actual type approval documentation (not just a marketing claim) takes real time if done properly.

A rushed decision here is where a lot of downstream problems start. If you want a structured way to shortlist vendors rather than picking the first quote you receive, our guide on reading an RECD test certificate is worth reviewing before you sign anything, since a vendor’s own paperwork is one of the fastest ways to separate a credible operator from one cutting corners.

Budget a realistic 1 to 2 weeks for this stage if you’re comparing more than one vendor, and expect it to compress to a few days if you already have a preferred supplier and simply need a fresh quote for a new unit or capacity.

T-Minus 21 Days: Site Survey and Technical Assessment

Once you’ve selected a vendor, the next step is a technical assessment, either an in-person site visit or a detailed remote review depending on your vendor’s process. This is where the exact dimensions of your exhaust system, the available mounting space, chimney height, and structural constraints get recorded.

This step matters more than it looks. An RECD that’s sized or configured wrong for your exhaust geometry is a common source of the exhaust backpressure problems we cover in detail in our exhaust backpressure guide, so a thorough survey now genuinely saves time and trouble later. Enclosed, soundproofed gensets typically need a slightly longer survey than open-frame units, since the canopy adds constraints on mounting position and ventilation that an open unit doesn’t have.

Expect 1 to 3 days for the survey itself, plus a few more days for the vendor to translate that survey into a formal technical drawing and specification sheet for your sign-off.

T-Minus 18 to 20 Days: Order Confirmation and Fabrication Begins

With the technical drawing approved and commercial terms settled (advance payment, delivery commitment, warranty terms), fabrication of your specific RECD unit begins. This is also roughly the point where you should confirm the installation date window with your vendor, even though it’s still weeks away, so both sides are planning toward the same target.

If your facility needs to coordinate a shutdown window with other departments, security, or building management, this is the moment to start that internal process too. A shutdown that needs three weeks of internal notice shouldn’t be arranged the week fabrication finishes.

T-Minus 14 Days: Fabrication, Mid-Point

RECDs are not off-the-shelf products picked from a shelf. Each unit is fabricated to match your generator’s exhaust diameter, mounting orientation, and capacity band, which is why this stage takes 2 to 4 weeks rather than a few days. During this window, the vendor’s workshop is building the housing, fitting the filtration or catalytic media appropriate to your capacity, and preparing mounting hardware specific to your site survey.

There’s genuinely not much for you to do during this stretch beyond staying reachable if the vendor has a clarifying question, and using the time productively to prepare your site (covered next).

Capacity has a real effect on this window. A smaller unit, in the 25 to 125 kVA range, tends to sit toward the shorter end of the 2 to 4 week band. Larger units, especially above 500 kVA, more often land toward the longer end, simply because there’s more material and more precision fitting involved. If you’re deciding between a retrofit and a full replacement partly on the basis of how long you can afford to wait, our RECD vs new CPCB IV+ genset cost comparison post covers how fabrication lead time factors into that broader decision.

T-Minus 3 Days: Pre-Installation Prep at Your Site

With fabrication nearing completion, attention shifts back to your site. This is when you should be confirming: the exact shutdown window with all internal stakeholders, safe and clear physical access to the generator (removing anything blocking the exhaust area), any permits or internal work-clearance documentation your facility requires for hot work or structural modification, and a backup power plan if this generator is your primary or sole backup source during the installation window.

That last point deserves emphasis. If this DG set is your only backup power source, a 1 to 3 day installation window is also a 1 to 3 day window without backup power, unless you arrange a temporary alternative. Plan around that deliberately rather than discovering it the morning of installation.

T-Minus 1 Day: Final Checks

The day before installation, a competent vendor will confirm the crew, transport logistics for the fabricated unit, and tools arriving on schedule. This is also a good moment for you to do a final walk-through of the access route and confirm nothing has changed since the site survey (new equipment stored nearby, a locked area, and so on).

Day 1: Installation Begins

This is the day your generator actually goes offline. For a typical single open-frame unit in a common capacity range, physical installation itself often completes within a single working day, roughly 4 to 8 hours depending on complexity. The work generally proceeds through: safe shutdown and isolation of the generator, removal or modification of the existing exhaust section, mounting of the RECD unit in the position confirmed during the site survey, reconnection and sealing of the exhaust path, and any required electrical or sensor connections depending on the RECD model.

Enclosed and soundproofed gensets typically take longer than open-frame units at this stage, since the canopy itself often needs to be opened, modified, and resealed around the new unit, which is one reason enclosed installations more commonly run into Day 2.

Day 2 to 3: Multi-Day and Larger Installations

Larger-capacity units, multiple generators being fitted at the same site, or enclosed gensets requiring canopy modification commonly extend physical installation into a second or third day. This isn’t a sign anything has gone wrong; it’s simply proportional to the scope of physical work involved. If you’re fitting several DG sets at one facility, most vendors will sequence them rather than take every generator offline simultaneously, so your facility isn’t left without any backup power at any point during the project.

Day 3 to 4: Commissioning and Testing

Once the RECD is physically mounted and connected, the installation crew runs the generator and checks the fit under real operating conditions. This includes confirming there’s no exhaust leak, checking that backpressure readings fall within the manufacturer’s specified range for your engine, and running an initial performance check.

This step is not optional and shouldn’t be skipped even under time pressure. A unit that looks correctly mounted but hasn’t actually been tested under load is an installation that hasn’t really been finished yet, and rushing past this stage is one of the more common installation mistakes we see reported.

T-Plus 7 Days: Documentation Catches Up

With the physical work complete, the paperwork side of the project finishes over the following days: your installation or compliance certificate, updated technical documentation reflecting the fitted unit, and any records your vendor needs to submit or provide for your pollution control board file. This typically takes another 3 to 10 days after commissioning, depending on your vendor’s internal processing and how quickly signatures and approvals move.

Don’t treat installation as complete until this paperwork is in hand. A generator with an RECD physically fitted but no corresponding documentation is not yet in a defensible compliance position, and our test certificate reading guide is worth reviewing again once these documents land, so you know exactly what you’re checking for.

T-Plus 30 Days: First Check-In

A reasonable vendor will schedule or recommend an initial follow-up check within the first month of operation, confirming the unit is performing as expected under your actual load conditions rather than just the conditions present on installation day. This isn’t full maintenance yet (our RECD maintenance guide covers the ongoing cleaning and regeneration schedule), but it’s a useful early checkpoint to catch anything that only shows up after a few weeks of real-world running.

What Stretches or Compresses This Timeline

A few variables move this schedule meaningfully in either direction, and it’s worth knowing which ones apply to your situation before you commit to a date.

Capacity. Smaller units generally fabricate faster; larger units, especially above 500 kVA, involve more material and more precise fitting, and commonly push toward the longer end of the fabrication window.

Open versus enclosed genset. Enclosed, soundproofed units almost always add time to the physical installation day, since the canopy has to be worked around rather than simply accessed.

Number of units. Multi-generator sites take proportionally longer, though usually not a straight multiple of single-unit time, since fabrication for multiple units can often run in parallel at the vendor’s workshop even though on-site fitting is typically sequenced.

Site readiness. A site with clear access, complete technical documentation, and internal approvals already in place moves faster than one where the vendor is waiting on information or physical access mid-project.

Custom fabrication needs. Unusual chimney heights, tight mounting spaces, or exhaust configurations that don’t match standard patterns can add fabrication time, since more of the unit needs to be custom-built rather than assembled from standard components.

Season and logistics. Heavy monsoon periods or peak compliance-deadline seasons, when many facilities are rushing to install before a regulatory cutoff, can extend vendor lead times simply due to workshop capacity, independent of your specific installation’s complexity.

How This Compares to Other Compliance Paths

If you’re weighing RECD against a dual-fuel kit or a full generator replacement, timeline is one of the factors worth putting on the table alongside cost. Our RECD vs dual fuel kit comparison and our RECD vs DPF post both touch on how installation scope differs across these options. As a general pattern, RECD retrofit timelines (weeks, not months) are considerably shorter than sourcing and commissioning an entirely new CPCB IV+ generator, which typically involves a longer manufacturing and delivery lead time on top of its own installation and commissioning process. If cost, not just time, is the deciding factor for you, our dedicated RECD vs new CPCB IV+ genset cost comparison lays out both paths side by side.

A Checklist for Staying on Schedule

Use this to keep your own project on the timeline above rather than drifting past it:

Confirm your vendor’s CPCB approval and read their sample documentation before signing, not after.

Schedule the site survey promptly once a vendor is selected; delays here push everything downstream.

Start internal shutdown-window approvals as soon as fabrication begins, not the week installation is due.

Arrange backup power coverage in advance if this generator is your sole backup source.

Clear physical access to the generator and exhaust area before installation day.

Insist on a commissioning test run before treating the job as finished, regardless of time pressure.

Confirm you have received installation and compliance paperwork, not just a verbal confirmation that the job is done.

A Note for Multi-Site or Multi-Generator Projects

Everything above describes a single generator at a single site. If you’re coordinating RECD installation across several DG sets, whether at one large facility or multiple locations, a few adjustments to this timeline are worth planning for.

Fabrication for multiple units of the same capacity can often proceed in parallel at the vendor’s workshop, so ordering five 125 kVA units doesn’t necessarily mean a five-times-longer fabrication window, though it does mean confirming your vendor actually has the workshop capacity to run that many builds simultaneously rather than queuing them one after another. Ask directly rather than assuming.

On-site fitting, by contrast, is usually sequenced generator by generator, both because most sites don’t want every backup source offline at once and because a single crew typically can’t be in two places at the same time. For a multi-generator site, expect the total on-site installation window to stretch across several days to a couple of weeks depending on how many units are involved and how your facility wants downtime staged.

The practical implication is that your overall project timeline for a multi-generator rollout is closer to “fabrication time plus (installation days multiplied by number of units, staged around your operational needs)” rather than a simple multiple of the single-unit timeline above. Discuss a staging plan with your vendor early, ranked by which generators carry the most compliance urgency or the least operational risk if taken offline first.

Frequently Asked Questions

Can RECD installation be done without shutting down the generator? No. The exhaust system has to be safely isolated for the physical work to be done, which means the generator is offline during that window. This is why scheduling around a planned maintenance window or low-usage period, rather than an emergency, generally produces a smoother project.

Why does fabrication take weeks when the physical fitting only takes days? The fitting itself is comparatively quick because the unit arrives pre-built to your generator’s exact specifications. The weeks happen earlier, in the workshop, where that custom fit is actually manufactured. Skipping or shortening this stage generally means a less precise fit, not a faster overall project.

Does capacity really change the timeline that much? Yes, though usually at the margins rather than dramatically. A 125 kVA unit and a 1000 kVA unit both broadly follow the same stages described above, but the larger unit tends to sit toward the longer end of each range, particularly for fabrication.

What happens if my site isn’t ready when the fabricated unit arrives? Most vendors will hold the unit and reschedule installation, which simply pushes your completion date back by however long the readiness gap is. This is one of the more avoidable sources of delay, which is why the T-minus 3 days and T-minus 1 day prep steps above matter as much as they do.

Is there a faster option if I’m under a hard compliance deadline? Talk to your vendor directly and early. Some fabrication timelines can be compressed for standard capacity bands with sufficient notice, though this typically isn’t possible for large or unusual configurations. Reach out through our contact page if you’re working against a specific deadline and want a realistic assessment of what’s achievable, and see our emission regulations overview for the compliance context driving most deadline-driven installations.

Does the timeline change if I’m choosing between RECD and another compliance route, like a dual-fuel kit? Broadly similar in structure (a fabrication or sourcing period followed by a shorter on-site fitting window), but the specifics differ enough that it’s worth comparing directly rather than assuming. Our RECD vs dual fuel kit post covers how the two technologies differ beyond just timeline, including what each is actually designed to solve.

What’s the single biggest cause of an RECD project running longer than expected? Site readiness, more often than fabrication delays. A vendor’s workshop generally runs on a fairly predictable schedule once fabrication begins, but a site that isn’t prepared for installation day (access blocked, internal approvals not yet secured, no backup power plan arranged) is the most common reason a project slips past the timeline outlined above.

Bringing It Together

Realistically, plan for 3 to 5 weeks from decision to a fully documented, commissioned RECD installation, with only a few of those days actually taking your generator offline. The single biggest lever you control is how quickly the decision, survey, and site-preparation stages move, since fabrication itself runs on a fairly fixed schedule once it starts. Whether you’re installing on a 125 kVA, a 400 kVA, or a 1000 kVA generator, the stages above hold; only the exact number of days at each stage shifts with capacity and complexity.