Retrofitted Emission control device for a generatorChoosing a requires more than checking the generator's kVA rating and comparing product prices. The RECD must be technically appropriate for the engine, compatible with the existing installation, supported by relevant certification documentation, and operated within the conditions for which it was evaluated.

For facility managers and generator owners, understanding the important specifications before purchasing an RECD can prevent compatibility problems, installation delays, and unnecessary operating costs.

What Are the Key RECD Specifications?

An RECD specification sheet may contain considerably more information than the product's physical dimensions.

Important parameters can include:

Applicable engine family
Engine power range
RECD family
RECD model
After-treatment technology
Particulate reduction performance
Exhaust flow requirements
Permissible exhaust back pressure
Temperature limits
Pressure monitoring
Sensor configuration
Controller functionality
Installation requirements
Maintenance requirements
Certification information

Not every specification applies in the same way to every RECD. The manufacturer's technical documentation should therefore be reviewed alongside the generator's engine information.

1. Engine Compatibility

Engine compatibility should be the first specification to verify.

An RECD designed for one engine family should not automatically be assumed to be suitable for another simply because both engines have similar power ratings.

CPCB's revised RECD procedure provides a framework for RECD families and their applicability to tested engine families.

Before requesting a quotation, record:

Engine manufacturer
Exact engine model
Rated power
Engine manufacturing date
Emission stage
DG-set manufacturer
Existing exhaust arrangement

These details allow the supplier to evaluate the appropriate RECD configuration.

2. Rated Power Range

The generator's capacity is an important selection parameter, but it should not be the only one.

A supplier may specify an applicable power range for an RECD family.

For example, a product may be designed for a particular range of engine outputs rather than every generator from a certain kVA category.

This distinction matters because generator electrical output and engine mechanical power are not necessarily interchangeable specifications.

engine model and rated powerAlways ask the supplier to confirm applicability using the , not only the generator's kVA rating.

3. RECD Family and Model

A manufacturer may offer multiple RECD models or configurations.

The quotation should clearly identify the exact product being supplied.

Ask for:

RECD family:

The certified product family to which the device belongs.

Model:

The specific product configuration.

Application:

The engine family and power range for which it is intended.

Configuration:

The relevant installation and technical arrangement.

Avoid accepting a quotation that simply states “RECD system” without identifying the actual model.

4. Particulate-Matter Reduction

Particulate-matter reduction is a central consideration in RECD evaluation.

CPCB's revised procedure specifies a minimum 70% particulate-matter reduction requirement for applicable Phase-I and Phase-II engines through retrofitted after-treatment devices under the prescribed testing framework.

When reviewing product specifications, ask:

What PM reduction was demonstrated?
Under which testing procedure?
Which engine was tested?
Which RECD family was evaluated?
Does the documentation apply to the product being quoted?

This prevents a general performance statement from being confused with product-specific certification.

5. Exhaust Back Pressure

Exhaust back pressure is an important technical parameter when installing an after-treatment device.

An improperly selected or installed system can create excessive resistance in the exhaust path.

CPCB's procedure specifically states that engine-operation modifications affecting baseline emissions must remain within limits specified by the original engine manufacturer, including maximum allowable exhaust-gas back pressure.

Therefore, the RECD supplier should consider the engine manufacturer's applicable exhaust limitations when designing the installation.

Do not select an RECD only by physical pipe size.

The exhaust flow and pressure characteristics also need to be considered.

6. Exhaust Temperature

Temperature can be important for the operation and durability of an after-treatment system.

The supplier should provide applicable temperature limits and installation requirements.

Depending on the technology, temperature information may also be monitored electronically.

Before installation, determine:

Expected exhaust temperature
RECD operating temperature range
Sensor location
Maximum allowable temperature
Temperature monitoring requirements

This information can also assist with maintenance and fault diagnosis.

7. Sensors and Monitoring

A modern RECD can incorporate sensors that monitor operating conditions.

Depending on the system design, sensors may be used for:

Temperature measurement
Pressure measurement
System monitoring
Fault detection
Performance-related diagnostics

The exact sensor configuration varies between manufacturers.

Ask for a complete sensor list in the technical proposal rather than assuming that every RECD includes the same monitoring functions.

8. Controller Specifications

RECD controller for diesel generatorsThe can act as an important interface between the emission-control equipment and the operator.

Depending on the product, the controller may provide:

Temperature monitoring
Pressure monitoring
Alarm generation
Fault indication
System-status display
Diagnostic information
Selected control functions

Before purchasing, ask whether the controller is:

Included in the quotation
Optional
Installed separately
Supplied with a display
Connected to existing generator controls

The supplier should explain exactly which functions are supported.

9. Physical Dimensions

The physical size of the RECD matters when the generator room has limited space.

Check:

Length
Width
Height
Weight
Mounting orientation
Inlet/outlet arrangement
Required clearance
Maintenance access

A product may fit the exhaust pipe but still be unsuitable if there is insufficient space for inspection or servicing.

For indoor generator rooms, installation clearances should be assessed before finalizing the product.

10. Exhaust Connection

The RECD must be compatible with the existing exhaust arrangement or a properly designed modification.

The technical assessment may consider:

Exhaust-pipe diameter
Connection type
Exhaust flow
Mounting arrangement
Supports
Expansion considerations
Insulation
Access for maintenance

A professional installation should account for the entire exhaust arrangement rather than treating the RECD as an isolated component.

11. Electrical Requirements

If the RECD includes a controller, sensors, alarms, or other electronic components, electrical requirements should be included in the specification review.

Ask about:

Power supply
Voltage
Current requirements
Wiring
Protection
Communication interfaces
Alarm outputs
Environmental rating

These details can help the facility's electrical team plan the installation.

12. Operating Environment

The installation environment can affect equipment selection.

Consider:

Indoor or outdoor installation
Ambient temperature
Dust
Moisture
Vibration
Accessibility
Available ventilation
Exposure to heat

The manufacturer should specify the environmental conditions within which the control system and electronic components are designed to operate.

13. Maintenance Requirements

An RECD should be evaluated not only by its purchase specification but also by its maintenance requirements.

Ask the supplier:

How frequently should the system be inspected?
What components require cleaning?
How is pressure monitored?
How are faults identified?
Which components are replaceable?
What is the recommended service interval?
What maintenance records should be maintained?

A system that is easy to monitor and service can be more practical for facilities with limited maintenance staff.

14. Certification Documentation

Certification documentation is one of the most important parts of the procurement process.

CPCB's revised procedure provides requirements relating to Type Approval and Conformity of Production for applicable RECDs.

Ask the supplier to provide documentation identifying:

Manufacturer
RECD family
Model
Applicable engine family
Power range
Certification agency
Type-approval information
Relevant conformity information

Do not rely solely on a brochure statement such as “CPCB approved.”

15. Original Engine System Modifications

An RECD installation should not unnecessarily interfere with the original engine emission-control system.

CPCB's procedure states that the original engine emission-control system should not be modified except under specified conditions, including modifications permitted in writing by the original engine manufacturer or specific provisions within the procedure.

This makes technical planning especially important for engines that already have emission-control components.

The supplier should clearly explain any proposed modification.

16. Secondary Emissions

A complete RECD evaluation is not limited to particulate reduction.

CPCB's procedure includes provisions concerning secondary emissions and requires assessment where applicable.

For buyers, this reinforces an important principle:

Do not evaluate an RECD solely on one performance number.

A proper technical evaluation should consider the overall effect of the retrofit on the engine and its emissions.

17. Durability

An RECD needs to maintain its intended performance during its service life.

CPCB's procedure includes durability-related provisions as part of the approval framework.

When comparing products, ask:

What durability information is available?
What service interval is recommended?
Which components have a defined replacement period?
What conditions can reduce performance?
What maintenance is required to preserve performance?

This information can be more valuable than a simple initial purchase price.

18. Installation Checklist

Before installation begins, confirm:

Generator

Engine manufacturer identified
Exact engine model confirmed
Rated power verified
Manufacturing information recorded
Emission stage identified

RECD

Exact model identified
RECD family identified
Engine compatibility confirmed
Power range confirmed
Technical specification reviewed

Exhaust

Pipe dimensions checked
Exhaust flow considered
Back-pressure limits checked
Mounting arrangement planned
Supports evaluated
Maintenance access available

Controls

Controller specification reviewed
Sensors identified
Power requirements confirmed
Alarm functions understood
Wiring plan prepared

19. Certification Checklist

Before placing an order, request:

Type-approval documentation
RECD family information
Applicable engine family
Product model
Certification agency
Relevant testing information
Conformity information where applicable
Manufacturer details
Current documentation

CPCB maintains a Generator Sets section that includes Type Approval/COP information, making the official CPCB website an important reference when checking current documentation.

20. Commercial Checklist

Technical suitability should be accompanied by a clear commercial proposal.

Confirm whether the quotation includes:

RECD equipment
Controller
Sensors
Installation
Exhaust modifications
Transportation
Commissioning
Warranty
Training
Maintenance
Spare parts
Taxes

Comparing quotations on the same scope makes procurement much easier.

How to Select the Right RECD Specification

A practical selection process can be divided into five stages.

Stage 1: Identify

Collect complete DG-set and engine information.

Stage 2: Match

Identify RECD families applicable to the engine.

Stage 3: Verify

Check certification and technical documentation.

Stage 4: Design

Evaluate exhaust, electrical, space, and installation requirements.

Stage 5: Support

Review maintenance, warranty, spare parts, and technical service.

This approach is more reliable than selecting an RECD from a catalogue based only on generator capacity.

Red Flags During Procurement

Be cautious if a supplier:

Refuses to identify the exact RECD model
Provides no engine applicability information
Uses only generic “CPCB approved” language
Cannot provide certification documentation
Gives a quotation without understanding the generator
Ignores exhaust back-pressure requirements
Provides no maintenance information
Offers no clear warranty
Cannot explain controller functions
Avoids questions about technical support

These issues do not automatically prove that a product is unsuitable, but they justify further verification before purchase.

Why Documentation Matters After Installation

Keep the complete RECD documentation at the facility.

A useful project file can include:

Purchase order
Technical quotation
RECD model details
Certification documents
Installation report
Commissioning report
Warranty certificate
Maintenance schedule
Service records
Replacement records

Good documentation makes future servicing and technical verification easier.

A 2026 RECD Compliance-Oriented Checklist

Before considering an installation complete, verify:

Technical

Correct engine identified
Correct RECD family selected
Power range confirmed
Exhaust requirements checked
Back-pressure limits considered

Certification

Product-specific documents received
Certification agency identified
Applicable engine range verified
Current documentation checked

Installation

Exhaust installation completed correctly
Sensors installed
Controller commissioned
Electrical connections checked
Maintenance access confirmed

Operation

Operator instructions received
Alarm functions understood
Maintenance schedule established
Service contacts recorded

Regulatory

Latest CPCB information reviewed
Applicable State requirements checked
Any site-specific environmental directions considered

What Facility Managers Should Remember

An RECD specification sheet should never be reviewed in isolation.

The specification needs to be matched against the actual generator.

For example, knowing that an RECD can handle a particular exhaust flow is useful only when the facility has confirmed its engine's operating conditions.

Similarly, knowing the product's PM-reduction performance is useful only when the certification documentation applies to the relevant RECD family and engine application.

This is why technical matching and documentation are equally important.

Final Takeaway

Retrofitted Emission control device for the generatorRECD controller for diesel generatorsA should be selected through a combination of technical evaluation, certification verification, installation planning, and lifecycle considerations. The most important specifications include engine applicability, power range, RECD family, particulate-reduction performance, exhaust back-pressure limits, temperature requirements, sensor configuration, controller functionality, physical dimensions, electrical requirements, maintenance needs, and certification documentation. CPCB's revised RECD procedure provides detailed provisions concerning Type Approval, RECD families, engine applicability, particulate reduction, secondary emissions, durability, and modifications affecting engine operation. The correct process is to identify the exact engine, determine the applicable RECD family, verify the certification documentation, evaluate exhaust and installation requirements, review the controller and sensors, and establish a realistic maintenance and service plan. The can further improve system monitoring where the selected technology provides controller-based diagnostics, alarms, and parameter monitoring. Its exact capabilities should always be confirmed from the manufacturer's technical documentation.

Retrofitted Emission Control Device for Generator: Specifications & Compliance Checklist

What to Look For - Technical Specs, Certification & Compliance - Before Making a Decision