Installing an RECD device as per CPCB norms can be an important step when evaluating emission-control requirements for an eligible in-use diesel generator. But many problems occur not because the concept of an RECD is complicated, but because basic purchasing, technical, installation, and documentation mistakes are made along the way.

The Central Pollution Control Board (CPCB) has published a specific system and procedure for emission-compliance testing of Retrofit Emission Control Devices (RECDs) for diesel power-generating-set engines up to 800 kW gross mechanical power. The procedure was revised on July 24, 2023. For a generator owner, following the right process is therefore just as important as selecting the equipment itself.

Mistake 1: Choosing an RECD Only by Generator kVA

One of the most common purchasing mistakes is selecting a product simply because its advertised range appears to match the DG set's kVA rating.

For example, a buyer may say:

“I have a 500 kVA generator, so I need a 500 kVA RECD.”

That approach can be incomplete.

CPCB's published RECD information identifies applicability according to the in-use diesel genset engine's power range in kW. The published manufacturer list also notes that corresponding kVA ratings should be checked against the relevant data plates.

What to do instead

Collect the actual:

• Engine manufacturer

• Engine model

• Engine serial number

• Gross mechanical power

• Generator rating

• Applicable phase

Use the engine information as the starting point for technical evaluation.

Mistake 2: Assuming Every RECD Fits Every Generator

An RECD is not automatically interchangeable between all diesel generators.

Different products can have different documented application ranges.

CPCB's published manufacturer list identifies different RECD manufacturers and product applicability across different power ranges and Phase I, Phase II, or both.

That means the buyer should verify the exact product rather than assuming that any RECD will work on the generator.

Better approach

Before ordering, ask the supplier:

“Is this exact RECD model applicable to my engine model and power range?”

Request the answer in writing wherever possible.

Mistake 3: Accepting “CPCB Approved” Without Checking the Product

A supplier may describe a product as “CPCB approved” or “CPCB compliant.”

Those phrases alone are not enough for technical verification.

The buyer should ask for:

• Manufacturer name

• Exact RECD model

• Part number

• Applicable engine range

• Applicable power range

• Phase applicability

• Certification/test information

• Certification agency

CPCB's published RECD material provides manufacturer and certification-agency information for listed products.

Why this matters

A company may offer multiple products or configurations.

Therefore, the relevant question is not simply:

“Is this company associated with RECDs?”

It is:

“Is this exact product applicable to my generator, and what documentation supports that application?”

Mistake 4: Ignoring the Existing Exhaust Arrangement

Even if the RECD is technically suitable, the physical installation can create challenges.

The existing exhaust system should be checked before the purchase is finalized.

Look at:

• Pipe diameter

• Flange arrangement

• Pipe direction

• Number of bends

• Available straight length

• Silencer position

• Mounting points

• Available clearance

• Maintenance access

A site photograph can help, but complicated installations may require a physical inspection.

Why early inspection helps

If the exhaust needs modification, the project may require:

• New flanges

• Pipe sections

• Structural supports

• Brackets

• Additional fabrication

• Electrical work

These costs can be avoided from becoming surprises by discussing them before the purchase order.

Mistake 5: Forgetting About Exhaust Back Pressure

Exhaust back pressure should not be treated as a minor detail.

Adding equipment to the exhaust system changes the overall arrangement, so the effect on back pressure should be evaluated.

CPCB's RECD procedure includes exhaust back pressure among the parameters considered during the testing framework.

What the owner should ask

Ask the supplier or technical team:

• What is the expected exhaust back pressure?

• How does the proposed installation affect the existing exhaust?

• Does the installation remain within the engine manufacturer's applicable limits?

This is an engineering consideration that should be addressed before commissioning.

Mistake 6: Comparing Only the Equipment Price

The cheapest RECD quotation is not necessarily the cheapest complete project.

One supplier might quote only the equipment.

Another may include:

• RECD

• Controller

• Sensors

• Exhaust fabrication

• Installation

• Wiring

• Commissioning

• Transportation

• Warranty

Therefore, compare the total installed cost.

Mistake 7: Not Asking What Is Included in Installation

Never assume that installation is included simply because the supplier has provided an equipment quotation.

Ask specifically whether the quotation includes:

• Mechanical installation

• Exhaust modification

• Structural support

• Electrical wiring

• Controller installation

• Sensor installation

• Commissioning

• Testing

If these items are excluded, obtain separate costs before approving the purchase.

Mistake 8: Ignoring Installation Space

DG rooms can have limited space, particularly in commercial buildings, hospitals, factories, offices and industrial facilities.

Before purchasing, check:

• RECD dimensions

• Weight

• Mounting position

• Lifting access

• Maintenance clearance

• Exhaust routing

• Structural support

A product may be technically appropriate but difficult to install in the existing room.

This is why physical assessment can be valuable for complex projects.

Mistake 9: Not Asking for Installation Instructions

A professionally documented RECD should come with appropriate installation information.

CPCB's RECD procedure includes requirements concerning retrofit installation instructions and end-user service and maintenance information.

Before installation, the owner should understand:

• Installation location

• Connection requirements

• Mounting arrangement

• Exhaust configuration

• Electrical requirements

• Maintenance access

Do not allow critical installation decisions to be based solely on verbal instructions.

Mistake 10: Treating the RECD as a “Fit and Forget” Product

Installing the device does not mean the owner can forget about it.

The RECD becomes part of the generator's operating system and should be maintained according to the manufacturer's instructions.

Depending on the product, maintenance may involve:

• Visual inspections

• Exhaust checks

• Sensor checks

• Controller checks

• Cleaning

• Component inspection

• Replacement of specified parts

The exact maintenance schedule should come from the product manufacturer.

Mistake 11: Ignoring the Condition of the DG Set

An emission-control retrofit should not be considered a substitute for normal generator maintenance.

Before installation, review the condition of the DG set.

Areas worth checking include:

• Engine servicing

• Fuel system

• Air intake

• Lubrication

• Cooling

• Exhaust system

• Existing smoke

• Operating load

If the engine has an underlying mechanical issue, it should be investigated separately.

Good generator maintenance remains important for reliable operation.

Mistake 12: Assuming an RECD Solves Every Emission Issue

Another common misunderstanding is expecting an RECD to address every possible emission-related issue.

The technology and testing framework apply to specific emission-control objectives and applications.

CPCB's published RECD procedure establishes requirements for emission-compliance testing of retrofit emission-control devices for eligible diesel genset engines.

Therefore, owners should understand exactly what the selected product is designed and documented to address.

Avoid making broad claims about every emission parameter unless they are supported by the product's technical documentation.

Mistake 13: Using Generic Pollution-Control Equipment as a Substitute

A generic exhaust treatment product should not automatically be assumed to have the same status as an RECD under the CPCB framework.

When a supplier offers an alternative product, ask:

Is this exact product being supplied as an RECD?

Then request the relevant supporting documentation.

This is particularly important when the purchase is being made for a compliance-related purpose.

Mistake 14: Failing to Verify the Certification Agency

CPCB's published RECD manufacturer list identifies certification agencies for listed products, including ICAT and ARAI in the published information.

When documentation is provided, check that the:

• The manufacturer matches the quoted product.

• Product/model can be identified.

• Applicable power range is clear.

• Certification agency is identifiable.

• Documentation relates to the product being purchased.

Do not accept an unrelated certificate simply because it contains the words “RECD” or “CPCB.”

Mistake 15: Assuming One Certificate Covers Everything

Another mistake is treating any certificate from a manufacturer as universal evidence for every product, engine and application.

CPCB's procedure includes a framework involving RECD families and type approval.

For buyers, the practical lesson is simple:

Check the relationship between the certificate, product model, family and application.

If the relationship is unclear, ask the supplier for clarification.

Mistake 16: Not Keeping Installation and Service Records

After installation, don't throw away the paperwork.

Maintain records of:

• Purchase order

• Product model

• Certification/test documents

• Installation date

• Installation report

• Commissioning report

• Warranty

• Service visits

• Maintenance

• Replacement components

This creates a useful history for the generator.

It can also help technicians understand what equipment has been installed when servicing the DG set later.

Mistake 17: Ignoring Warranty Conditions

A warranty is useful only when the owner understands what it covers.

Ask:

• How long is the warranty?

• Which components are covered?

• Does installation affect warranty?

• Are consumables excluded?

• What conditions can invalidate the warranty?

• Who handles warranty service?

• What is the response process?

Get the warranty terms in writing.

Mistake 18: Choosing a Supplier Without Checking Technical Support

An RECD project does not necessarily end when the equipment is delivered.

Technical support can matter during:

• Installation

• Commissioning

• Troubleshooting

• Maintenance

• Component replacement

A supplier with clear service arrangements can make long-term operation easier.

Before purchasing, ask about:

• Service coverage

• Response process

• Spare-parts availability

• Technician support

• Preventive maintenance

Mistake 19: Assuming Old CPCB Information Is Still Current

Regulatory and technical information can change.

CPCB maintains current announcements and regulatory information on its official website. The Board's website also provides generator-related sections and technical resources.

Therefore, avoid making a compliance decision solely from:

• Old blog posts

• Outdated brochures

• Social-media posts

• Old quotations

• Unverified online claims

For compliance-sensitive decisions, check current official information.

How to Avoid These Mistakes: A Better Process

Instead of purchasing immediately, follow a simple sequence.

Step 1: Identify the DG Set

Record the engine model, gross mechanical power, generator rating and phase.

Step 2: Collect Exhaust Information

Record pipe diameter, configuration and available installation space.

Step 3: Shortlist Suitable Products

Ask suppliers for products matching the actual engine application.

Step 4: Verify Documentation

Review model information, test/certification references and applicable ranges.

Step 5: Review Installation

Confirm fabrication, mounting, controls, wiring and commissioning requirements.

Step 6: Compare Complete Quotations

Compare total installed cost rather than only the equipment price.

Step 7: Plan Maintenance

Understand the manufacturer's servicing requirements.

Step 8: Keep Records

Store technical, purchase, installation and maintenance documentation.

Step 9: Check Current Requirements

Verify the latest applicable CPCB information and any relevant state or site-specific requirements before finalizing the project.

What Is a DG Generator Emission Control Device?

A DG generator emission control device is a broad term describing equipment intended to control emissions associated with diesel-generator operation.

An RECD is a specific retrofit emission-control solution covered by the CPCB's applicable testing and certification framework.

Therefore, generator owners should avoid treating every product advertised as a pollution-control or emission-control device as automatically equivalent to an RECD.

The exact product identity, application and supporting documentation should be checked.

What Should You Do If You Already Bought a RECD?

If an RECD has already been purchased, don't panic if you have not reviewed all the documentation yet.

Start by collecting:

1. Purchase invoice

2. Product model

3. Manufacturer details

4. Technical datasheet

5. Certification/test documents

6. Installation manual

7. Maintenance manual

8. Installation report

9. Warranty document

Then compare the product information with the DG set's actual engine details.

If anything appears unclear, ask the supplier for written clarification.

When Should a Technical Inspection Be Considered?

A technical inspection is particularly useful when:

• The exhaust route is complicated.

• The DG room has restricted access.

• Multiple generators are installed.

• The engine information is incomplete.

• Major exhaust modifications are expected.

• The installation involves structural work.

• The generator is critical to facility operations.

A small amount of planning before installation can prevent larger problems after the equipment arrives.

Final Takeaway

Most RECD-related purchasing problems can be avoided by slowing down the decision-making process and verifying the basics. Don't choose an RECD only from the generator's kVA rating. Don't assume every RECD fits every engine. Don't accept a generic “CPCB approved” statement without checking the exact product and supporting documentation. Don't ignore exhaust configuration, back pressure, installation space or maintenance. For businesses evaluating a DG generator emission control device, the best approach is to treat the purchase as a technical project rather than a simple equipment transaction. Start with the engine details, verify the exact RECD model, review the available documentation, inspect the installation requirements and compare complete quotations. After installation, maintain the equipment and preserve service records.