Overview
EN ISO 8665-2:2024 - Small craft: Power measurements and declarations - Part 2: Electric marine propulsion (ISO 8665-2:2024) defines how to determine and declare the power of electric marine propulsion systems for small and recreational craft up to 24 m hull length. The standard establishes what manufacturers must report (declared power and speed), how to identify whether the declared value is motor power or propeller shaft power, and the test conditions and procedures used to verify those declarations.
Key topics and requirements
- Scope and applicability
- Applies to electric propulsion systems used on recreational and other small craft up to 24 m.
- Declaration rules
- A single declared power value must be accompanied by the declared motor speed.
- The declaration must explicitly state whether it is propeller shaft power or motor power.
- Propeller shaft power may be measured or given as motor power minus transmission losses.
- Definitions
- Clarifies terms such as power (kW), declared power, declared propeller shaft power, brake power, and net torque.
- Test conditions and procedures
- Representative production units and all auxiliaries intended for sale must be listed.
- Standard reference conditions for motor testing: air 25 °C ± 5 °C, relative humidity 30 %, and coolant 25 °C ± 5 °C for liquid-cooled systems.
- Electrical supply requirement: DC source with a maximum voltage drop of 5% (excluding transients under 10 s); test run at full setting of the power controller.
- Thermal equilibrium requirement: temperature rise gradient not varying by more than 2 K/h.
- Includes provisions for production conformity testing and requirements for the test report.
- Regulatory linkage
- Annex ZA maps the standard to essential requirements of Directive 2013/53/EU (owner’s manual declarations and, where relevant, EU declaration of conformity), providing a voluntary route to presumption of conformity.
Applications - who uses this standard
- Propulsion system manufacturers - to declare rated motor or propeller shaft power and demonstrate conformity.
- Test laboratories and conformity assessors - to perform standardized power measurement tests and produce compliant test reports.
- Boat builders and integrators - to verify that propulsion units meet declared performance for installation and documentation.
- Regulators and notified bodies - to evaluate compliance with Directive 2013/53/EU requirements related to power declaration.
- Dealers and end users - to compare rated power claims across products and check performance documentation.
Related standards
- IEC 60034-1 is referenced for motor power measurement methods and may be used in conjunction with EN ISO 8665-2:2024 for motor-specific testing details.
- EN ISO 8665 series - this document is Part 2, complementing other parts of the series on small craft power measurement and declaration.
Keywords: EN ISO 8665-2:2024, electric marine propulsion, power measurements, declared power, propeller shaft power, motor power, small craft, recreational craft, test methods, Directive 2013/53/EU.
