ISO 8528-9:2017

Overview

ISO 8528-9:2017 specifies procedures for the measurement and evaluation of external mechanical vibrations of reciprocating internal combustion (RIC) engine driven a.c. generating sets. It applies to fixed and mobile installations with rigid and/or resilient mountings for land and marine use, but excludes aircraft and propulsion for land vehicles/locomotives. The standard defines measurement locations, required operating conditions, instrument accuracy, evaluation ranges and reporting essentials to assess vibration severity and compatibility of components.

Key topics and requirements

• Scope & applicability: RIC engine driven generating sets; can be used as a basis for other reciprocating prime movers (e.g., gas or steam engines). Certain critical applications (hospitals, high-rise buildings) may need supplementary requirements.
• Measuring points: Recommended measurement locations on the solid engine block and generator main body (three directions: x, y, z) to avoid local structural resonances.
• Measuring devices & accuracy: Instruments shall deliver rms displacement and velocity with ±10% accuracy over 10 Hz–1 000 Hz and −20%/+10% over 2 Hz–10 Hz. Signals may be integrated or differentiated to derive quantities if accuracy is preserved.
• Operating conditions: Measurements under steady-state running, at operating temperature, rated frequency and rated power (or maximum attainable power).
• Frequency ranges for evaluation: Main excitation frequencies typically 2–300 Hz; overall evaluation range 2 Hz–1 000 Hz (displacement) and 10 Hz–1 000 Hz (velocity).
• Evaluation and acceptance: Guidance values (rms displacement and velocity) are provided (Table C.1) with two assessment levels indicating usual ranges, ranges requiring component assessment, and cases needing special design. Manufacturer remains responsible for component compatibility per ISO 8528-5:2013.
• Report contents: Test report must include generating set data, measurement equipment and measured values (See Annex D).

Applications and users

ISO 8528-9:2017 is used for:

• Type/acceptance testing, commissioning and site verification of generator sets
• Troubleshooting excessive vibration and diagnosing resonances
• Specifying vibration criteria in procurement and contracts
• Ensuring component compatibility (engine, alternator, mountings, accessories) Primary users:
• Generator manufacturers and test laboratories
• Marine and land installation engineers
• Classification societies and regulatory authorities
• OEM component suppliers and maintenance teams
• Consultants for critical installations (hospitals, data centers, high-rise buildings)

Related standards

• ISO 8528-5:2013 - Generating sets (component compatibility responsibilities)
• ISO 2041 - Vocabulary for mechanical vibration, shock and condition monitoring

Keywords: ISO 8528-9:2017, vibration measurement, generating sets, reciprocating internal combustion engine, mechanical vibrations, rms velocity, displacement, measuring points, vibration severity.