DG Nameplate Photos for RECD Enquiries: What Should You Capture?

Picture a sales engineer’s phone on a Monday morning. Forty-one WhatsApp attachments have arrived overnight from eleven different sites, each one an RECD enquiry. By lunch, fourteen of them have produced a usable first estimate. The other twenty-seven have produced the same reply: “Could you send the engine plate again, please?”

None of those twenty-seven senders were careless people. They were plant managers, facility heads and DG operators who did exactly what was asked, which was to send some photos of the generator. The trouble is that nobody told them what “some photos” means when the goal is to size a retrofit emission control device (RECD) for a specific engine.

This guide fixes that. It walks through the photos vendors reject most often, then lays out the shots that get a proper response the same day, how to take each one properly, and what to do when the nameplate is faded, painted over or missing. If you follow it, your enquiry will move from “please resend” to “here is your preliminary sizing” in one round trip.

Quick answer: the photo set in one glance

For a normal RECD enquiry you should capture ten things. A wide shot of the whole DG set, the genset (alternator) nameplate, the engine nameplate, the engine serial number stamping, any emission or CPCB compliance label, the exhaust path from the engine to the silencer, the silencer and stack outlet, the space around the exhaust (inside the canopy or room), the control panel showing the hour meter, and the surroundings that decide access and crane or trolley movement. Add a typed copy of every number you can read on the plates. Details of each shot follow below.

Why a photo can decide your quote

Many people assume an RECD is sized from the kVA rating alone. It is not. Type approval for RECDs is granted for defined engine capacity bands, and inside a band the actual device still has to be matched to the engine’s exhaust flow, temperature and permissible back pressure. That is why a 250 kVA set from one manufacturer and a 250 kVA set from another can end up with differently configured devices.

When a vendor looks at your photos, they are trying to answer six practical questions:

• Which engine is this? Make, model, rated power and serial number decide which approval band applies and what the exhaust characteristics are likely to be.
• How much power does it actually make? The engine’s rated power in kW is what matters for band selection, and it is printed on the engine plate, not always on the alternator plate.
• What does the exhaust path look like? Pipe diameter, bends, length and the existing silencer decide how much room there is to fit a device without pushing back pressure past limits. Pipe size, bends and silencers all add up to the total restriction an engine works against, as Aurora Generators explains, and our own explainer on how exhaust back pressure affects a DG set covers the mechanics.
• Will it physically fit? An RECD is a sizeable steel assembly. Canopy space, roof clearance and mounting options are all visible in photos.
• What is the set’s compliance history? Some sets carry an emission compliance label. Some do not. This tells the vendor which norms the set was built to.
• What condition is it in? Oil leaks, soot on the exhaust, corrosion and a cracked flexible bellow all change what a responsible vendor will recommend before fitting anything.

Good photos let the first conversation happen before anyone travels.

The Reject Pile: eight photos that get sent back

Every vendor keeps a mental pile of photos they cannot use. Here are the eight most common members of that pile, why they fail, and how to avoid joining them.

1. The Glare Wall

Nameplates are usually metal or laminated foil, and both reflect light. A flash photo of a shiny plate returns a white rectangle with a few hopeful characters at the edge. Outdoor sun on a canopy door does much the same thing.

The fix: turn the flash off. Shoot in shade or turn your body so your shadow falls across the plate. If the plate sits in a dark canopy, light it from the side with a torch held at a steep angle so the light skims across the surface. The raised or stamped characters pick up shadows, and the reflection slides off to one side.

2. The Crop

The plate is in frame but the left edge is cut, or the bottom row of figures is missing because the phone focused on the middle. Often it is the bottom row that holds the year of manufacture, the serial number or the rated speed.

The fix: leave a small margin around the plate on all four sides, and check the photo on screen before you leave. Zoom in on your own picture. If you cannot read every line, neither can the vendor.

3. The Long Shot

A photo taken from three metres away shows a beautiful generator and a plate the size of a postage stamp. The result looks great for a site album and is useless for sizing.

The fix: always take a pair. First the wide shot that shows where the plate sits on the machine, then a close shot that fills most of the frame with the plate. The wide shot proves the plate belongs to that machine, and the close shot lets the vendor read it.

4. The Rubbed Plate

Ten years of dust, oil mist, whitewash and repainting can make a plate look blank. People sometimes send it anyway, hoping the vendor will guess.

The fix: wipe the surface gently with a dry, soft cloth. A slightly damp cloth is fine for oily grime. Avoid solvents and abrasive pads because they can lift the printed characters, and never scrape paint with a blade. If characters are still hidden, photograph the plate at three angles and also send a pencil rubbing, which is done by laying thin paper over the stamped characters and rubbing lightly with the flat side of a pencil lead.

5. The Alternator-Only Photo

Many people photograph the plate that is easiest to reach, which is often on the alternator or the control panel. That plate describes the electrical side: kVA, voltage, current, frequency and power factor. It does not tell the vendor which diesel engine is driving it, and the engine is what the RECD is fitted to.

The fix: send both plates. The genset plate or alternator plate for electrical data, and the engine plate for engine model, rated power and serial number. If you want to understand what the electrical figures mean, our guide on how to read a generator’s kVA and kW rating explains each line.

6. The Twice-Compressed Screenshot

A photo forwarded through three chat groups and then screenshotted arrives soft and pixelated. Small characters such as serial numbers turn into guesses, and a “0” and an “8” become indistinguishable.

The fix: send original files. On most phones you can attach photos as documents or as “original quality” so the chat app does not shrink them. If that is not possible, email them directly from the phone gallery.

7. The Stale Reference

Someone sends a scanned invoice, an old catalogue page or a photo from the purchase brochure instead of the machine itself. The engine on site may have been swapped, overhauled or replaced since the paperwork was created, and a vendor cannot know.

The fix: paperwork is useful as a supporting document but never a substitute for what is bolted to the floor today. Photograph the machine as it is now, and add the paperwork only as a second layer.

8. The Missing Exhaust

Everything about the engine is sent, but nothing about the exhaust route. Yet the exhaust route is where the RECD will actually live. Without it, the vendor has to ask for more photos, or, worse, assume an “average” layout and quote against it.

The fix: follow the exhaust with your camera from the engine outlet to the very end of the stack. Five or six photos usually cover it. Include the silencer, any expansion bellows, the wall or roof penetration and the tip of the stack.

The keeper set: ten photos that get a same-day response

Once you know what to avoid, the ideal set is easy to describe. Think of it as ten frames, each with one job. The table below gives the job of each frame, what the vendor reads from it, and the mistake to steer clear of.

#	Photo	What to capture	What the vendor reads	Common miss
1	Whole DG set	Full set from about 3 to 5 metres, showing engine end, alternator end and canopy or frame	Layout, open frame or canopy, overall condition	Only the panel is shown
2	Genset or alternator plate	The whole plate, straight on	kVA, kW, voltage, phase, frequency, RPM, year, serial	Glare or cropped bottom row
3	Engine plate	The whole plate on the engine block or rocker cover	Engine make, model, rated power, rated speed, serial	Plate photographed on the alternator instead
4	Engine serial stamping	The number stamped in metal on the block, if separate from the plate	Confirms identity when the plate is missing or replaced	Number hidden under paint
5	Compliance label	Any CPCB, emission norm or type approval sticker	Which emission stage the set was built to	Sticker peeled and ignored
6	Exhaust path	Engine outlet, flexible bellow, pipe run, bends	Pipe diameter, length, number of bends	Only the last section shown
7	Silencer and stack	Silencer body, its plate if present, and the tip of the stack	Silencer type, existing restriction, discharge point	Silencer plate too dirty to read
8	Space around the exhaust	Inside the canopy or room, with something for scale such as a tape measure	Room for the device, mounting options	No sense of scale
9	Control panel and hour meter	Panel front with the running hours visible	Usage profile, age of engine in practice	Hour meter out of frame
10	Surroundings	Access route, roof or terrace, overhead obstacles	Crane or trolley needs, logistics	Site photos taken only at night

Ten photos is not a hard rule. If your set has more than one engine, repeat the whole sequence per engine.

What the numbers on each plate tell the vendor

Reading the plates yourself makes it much easier to notice a photo that did not come out. Here is a short field guide.

Engine plate. You will typically find the engine manufacturer and model, engine serial number, rated power in kW or horsepower, rated speed in RPM, number of cylinders or displacement, and often the year of manufacture. Rated power and model together tell the vendor which capacity band the set falls into.

Genset or alternator plate. This lists the electrical ratings: kVA, kW, voltage, current, frequency, phases, power factor, and often the insulation class and enclosure rating. The alternator plate also usually has its own serial number, which is different from the engine’s.

Compliance label. On sets built under emission norms, there may be a label or plate stating the norm the engine was certified to. This is useful context. It is not proof that the set is exempt from retrofit requirements, because that depends on the norm, the manufacturing date and your state rules. For example, the Maharashtra Pollution Control Board’s RECD circular, summarised by TeamLease RegTech, links applicability to engine categories and the time since manufacture, so the manufacturing year on your plate can matter.

Silencer plate. Not every silencer has one, but when it does, it names the maker and model. That helps the vendor judge how much restriction is already in the line before the RECD adds its own.

How to actually shoot a nameplate

Technique matters more than camera quality. Any phone from the last five years will do the job if you use it with a little care.

1. Stop the set first. Never photograph plates on a running generator. Exhaust parts are hot, moving belts and fans are dangerous, and vibration blurs the picture. Isolate the set and let it cool before you go near the exhaust.
2. Clean the plate. A dry cloth is usually enough. Do not use solvent on a printed plate.
3. Find the light. Daylight from the side is best. If you are inside a canopy, use a torch at a shallow angle rather than the phone flash.
4. Square up. Hold the phone parallel to the plate, not at a slant. A slanted photo squeezes the characters on one side and makes small digits unreadable.
5. Tap to focus. Touch the plate on the screen before you press the shutter so the phone does not focus on the shiny metal behind it.
6. Take two shots. One a little wider, one tight. If the plate has two columns of data, you may need two tight shots.
7. Check on screen. Zoom into your own photo. Read out every line. If you cannot, retake it now, because you will not get another chance without a return trip.
8. Name the files. Rename them or keep them in a folder per set, for example “DG1 engine plate”, “DG1 alternator plate”. This saves a lot of back and forth on multi-set sites.

Where the plates hide on different types of sets

Plates do not follow a single standard location. Here is where to look.

Open-frame sets. The engine plate is generally on the engine block near the fuel pump side, on the rocker cover, or on the side of the crankcase. The alternator plate is on the alternator body, close to the terminal box.

Canopy sets. Many have a summary plate on the outside of the canopy, and the more detailed engine and alternator plates are inside. The outer plate sometimes lists only the genset rating, so go inside for the engine plate. If you are unsure how these designs differ, our comparison of open frame and enclosed canopy generators will help you get oriented.

Sets in a generator room. You may be photographing around fixed pipework and ducts. Bring a torch and, if a plate is hidden behind a duct, a small inspection mirror.

Older sets that have been re-engined or rebuilt. The engine may not match the plate on the alternator or canopy. That is exactly why the engine plate and engine serial stamping deserve their own photos.

Send a typed copy of the numbers too

Even a good photo can lose a digit in compression, so send a typed copy of everything you can read. It also serves as a cross-check if the vendor later spots a mismatch. Here is a template you can paste into a message.

Site name and city:
Contact person and phone:
Number of DG sets at the site:

For each DG set:
DG set label (for example DG1):
Genset kVA rating:
Engine make and model:
Engine serial number:
Engine rated power (kW):
Rated speed (RPM):
Year of manufacture (engine and genset):
Alternator make and serial number:
Emission or CPCB label on the set (yes or no, and what it says):
Approximate running hours (from the hour meter):
Open frame, canopy or generator room:
Existing silencer: fitted or not fitted, and its make if known:
Exhaust pipe diameter if known:
Any known problems (smoke, oil leaks, overheating, high back pressure):
State where the set is installed:

Copy it, fill in what you can read, and leave anything you are unsure of blank rather than guessing. Vendors much prefer a gap to a wrong figure.

When the nameplate is missing, faded or painted over

This happens more often than people admit, particularly on sets that have been moved between sites or repainted during a plant refurbishment.

Look for the stamped serial number. Engines usually carry a serial number stamped into the block, independent of the printed plate. Ask a technician where it is on your model, photograph it with the light raked from the side, and send it with the engine make.

Check the paperwork. The purchase invoice, commissioning report, warranty card, annual maintenance contract or previous pollution board consent may contain the engine model and serial. Photograph these as supporting evidence.

Ask the original dealer. Manufacturers can usually identify a set from the serial number. Cummins, for example, advises owners to have the complete model, specification and serial number ready when contacting a dealer for service or parts, and the same logic applies to RECD enquiries.

Consider an on-site verification. If no plate can be recovered, a survey by the vendor’s technician will be needed. It is a small additional step that avoids fitting a device against a guess. If you are also planning to check the paperwork of a device you already own, see how the matching process works in our guide to verifying a CPCB tested RECD.

A replaced or missing plate should always be disclosed. If the engine was swapped, say so, and share whatever record you have of when and why.

Safety while you take the photos

Photography is a small task, but it happens around a machine that can hurt people. A few rules keep it uneventful.

• Switch the set to off and isolate it, and make sure nobody can start it while you are inside the canopy.
• Let the exhaust cool. Exhaust piping and silencers can stay hot long after shutdown.
• Do not lean over moving belts or fans, and keep loose clothing, lanyards and phone straps away from them.
• Stay clear of alternator terminals and live cable ends. You are there to read plates, not to open boxes.
• If the stack or silencer is on a roof or a terrace, follow your site’s work at height rules and photograph from a safe position instead of leaning over an edge.
• Report any leaks, cracks or loose fittings you notice, because they matter for the retrofit and for daily operation too. A regular routine such as our monthly maintenance checklist for diesel generators helps catch these before an RECD is planned.

Sites with more than one generator

A campus, hospital or factory with three or four sets can generate two hundred photos, and unlabelled photos from multiple sets are the fastest way to a wrong quote. A simple system helps.

• Give every set a label, such as DG1, DG2 and DG3, and paint or tape it visibly if there is none.
• Make one folder per set and put every photo of that set inside it.
• Add a rough sketch showing where each set sits relative to the building and to the other sets.
• Note which sets are running, which are standby, and which are being retired. The retirement plan matters, because it affects whether you should retrofit at all. Questions such as whether two generators can share one RECD or whether an RECD can move to another generator usually come up at this point, and we answer them in their own guides.

What happens after you send the photos

Sending photos starts a process. It is helpful to know what to expect so the next step does not surprise you.

1. First review. The vendor identifies the engine, determines the capacity band and checks whether the set falls within an approved range.
2. Clarifying questions. If anything is unclear, such as a plate that is unreadable or a missing exhaust photo, you will get a short list of requests.
3. Preliminary sizing and a budgetary quote. With complete photos, a vendor can usually give an indicative range. For typical price ranges by capacity, see our overview of RECD cost in India.
4. Site survey. For final confirmation, most vendors will still visit. Photos reduce risk, but they do not replace a technician who can measure the exhaust route, check the condition of the engine and confirm mounting arrangements. A responsible vendor will not promise a firm fixed price for a large or complicated installation on photos alone.
5. Fabrication and fitting. Timelines depend on capacity and site conditions. Our guides on the RECD installation process and on the installation timeline describe what happens at each stage.

A photo checklist you can take to site

Print this or save it on your phone.

• Set is stopped, isolated and cool.
• Plates wiped clean.
• Wide photo of the whole set.
• Genset or alternator plate, straight on, fully readable.
• Engine plate, straight on, fully readable.
• Engine serial stamping, if separate.
• Compliance or emission label, if any.
• Exhaust path in five or six photos, from engine to stack tip.
• Silencer and its plate.
• Space around the exhaust, with a tape measure for scale.
• Control panel with hour meter readable.
• Access route and surroundings.
• Typed copy of all numbers.
• Photos sent in original quality, in a labelled folder.

Frequently asked questions

Is a nameplate photo enough to get an exact RECD quote?

It is usually enough for a preliminary estimate, not a final firm quote. Photos let the vendor identify the engine, choose the capacity band and understand the exhaust layout. A site survey then confirms measurements, engine condition and mounting. Expect a vendor to ask for a visit before finalising an order, particularly for larger sets.

Which plate matters most, the alternator plate or the engine plate?

Both are needed, but the engine plate is the more important one for RECD sizing, because the device is fitted to the engine’s exhaust. The alternator or genset plate gives the electrical ratings and confirms the kVA capacity.

What if my generator has no plate at all?

Look for a stamped engine serial number on the block, check invoices and commissioning documents, and contact the original dealer with whatever identifiers you have. If none of that works, ask the vendor for a physical survey. Do not accept a quote based on a guess of the engine model.

Can I take these photos myself, or should a technician do it?

Anyone who can work safely near a stopped generator can do it, and the checklist above covers the essentials. If access is difficult, for example a roof-mounted stack or a cramped canopy, ask your maintenance contractor to do it. What matters is that the set is stopped, cool and isolated.

Ready to send your photos?

If you have already gathered your photos and typed numbers, share them with our team and we will help you identify the right capacity band and next steps. You can also browse our retrofit emission control device page for capacity-specific information, or reach the team through the contact page.

If you are also thinking about how an RECD may interact with your engine’s coverage, read our companion guide on whether installing an RECD affects your generator’s OEM warranty. A well-documented enquiry with clear photos makes that conversation with your OEM dealer easier too.