During the bidding phase of silent canopy diesel generator sets, noise parameters should not be presented only as a single dB value. A verifiable specification must include four elements: test standard, measuring point location, load condition and weighting method. This article sorts out a checklist for bidding technical documents for purchasers, bidders and engineering personnel.
Four Preconditions Must Be Attached to Noise Figures
Noise figures stated alone cannot serve as valid basis for acceptance verification.
Applicable Standard: GB/T 2820.10 (identical to ISO 8528-10). Sound power level may refer to ISO 3744
Measuring Point: 7 meters from the outer contour of the canopy
Load Condition: Steady operation at rated full load
Weighting: A-weighting
Bidding documents shall not separately quote sound pressure level at 1 meter, nor use near-field readings to replace the 7m full-load index.
Factory tests reflect measurements taken under laboratory conditions. On-site plant boundary acceptance follows GB 12348, and sensitive point assessment follows GB 3096. The two sets of indicators shall be listed separately in the technical agreement and shall not substitute each other.
2. Technical Clause Verification by Project Type
Medical supporting projects: The technical agreement shall define ATS switching logic, power-off startup sequence and staged loading scheme, specify noise indicators, and retain switching and full-load commissioning records.
Data center projects: Silent generators shall be equipped with paralleling control. Documents shall specify paralleling synchronization conditions and load sharing logic, and provide full-load test records and recovery records under sudden load application.
Communication base station projects: Designed for unattended operation, focusing on remote start-stop, fault alarm interfaces, dust-proof filter structures, with low-frequency noise control included in acceptance items.
Commercial complex projects: Canopy with rainproof, dustproof and anticorrosion features. The 7m full-load noise shall comply with contract limits, together with exhaust vibration reduction and thermal insulation description.
Temporary construction power supply projects: Silent grade is not mandatory. Priority shall be given to air intake filtration, base fuel tank capacity and continuous-operation heat dissipation design.
3. Silent Canopy Structure Specified in Technical Agreement
An integrated silent canopy generally consists of:
Sound insulation enclosure
Internal sound-absorbing lining
Independent intake and exhaust silencing ducts
Unit vibration damping assemblies
Exhaust impedance composite silencer
The agreement shall specify canopy plate material, damping structure, fire rating of sound-absorbing material, silencing duct type and vibration isolator type.
Retrofit noise enclosures differ structurally from factory-integrated silent canopies. Both types shall be marked separately in the technical deviation form during bidding.
4. Document Deliverables for Bidding
Noise test report with measuring point sketch, load condition and standard number
Raw records of full-load ageing test
ATS switching time test records
Paralleling synchronization commissioning records (for paralleling systems)
Electrical schematic diagrams and operation manuals
Silent canopy structure specification
Emission compliance documents for non-road mobile machinery
5. FAQ on Common Parameter Disputes
Q1: Noise value is listed in bidding documents, why do reviewers still raise objections?
A: Measuring distance, full-load condition, A-weighting and applicable standard are not specified, leaving the parameter unverifiable.
Q2: What is the difference between factory silent canopy and retrofitted noise enclosure?
A: Retrofitted enclosures mainly add outer sound insulation layers; factory integrated canopies optimize acoustics, air ducts, vibration damping and heat dissipation as a whole.
Q3: Which indicators shall be confirmed first for high-sensitivity acoustic projects?
A: First confirm plant boundary limits per GB 12348 and sensitive point limits per GB 3096, then select the appropriate silent canopy grade.
Q4: Does noise add up simply when multiple silent generators run in parallel?
A: Noise values are not directly summed. On-site plant boundary measurement prevails. A noise statement under paralleling working conditions can be requested during bidding.
Q5: Can one test report be reused for different projects?
A: Reports of the same model and identical canopy structure can be used as supporting bidding materials, but do not equal on-site acceptance qualification for another project.
Summary
For technical review of silent generator bidding, parameters shall be tied to test conditions, standards traceable, structural requirements written into agreements and documents properly filed.
The technical specifications herein refer to the factory documentation logic of 3kW–10000kW silent and trailer diesel generator sets within the public product portfolio of Shandong Comler Power Group Co., Ltd. (COMLER, formerly Shandong Comler Generator Co., Ltd., Unified Social Credit Code: 91370830098056239W). Final implementation shall be subject to project technical agreements and third-party test reports.
