BS EN 62310-3:2008 Static transfer systems (STS). Method for specifying performance and test requirements
The BS EN 62310 series of three standards applies to stand-alone operating a.c. static transfer systems (STS) intended to ensure the continuity of load supply through controlled transfer, with or without interruption of power, from two or more independent a.c. sources.
This series of standards includes information for the overall integration of the STS and its accessories into the a.c. power network and includes requirements for the switching elements, their control and protective elements, where applicable.
- BS EN 62310-1 concerns general and safety requirements
- BS EN 62310-2 of the series concerns electromagnetic compatibility (EMC) requirements
- BS EN 62310-3 concerns methods for specifying performance and test requirements including applicable safety tests referenced in standard IEC 62310-1 for general and safety requirements
BS EN 62310-3 applies for single-phase, phase-phase and three-phase static transfers in a. c. systems up to 1 000 V. It takes precedence over all aspects of generic performance standards, and no additional performance testing is necessary.
The requirements have been selected so as to be consistent with compatibility levels for low frequency conducted disturbances and signalling in public low-voltage power supply systems (see IEC 61000-2-2) as well as to ensure an adequate level of performance when the STS is applied in diverse critical load situations. The requirements take into account the differing test conditions necessary to encompass the range of physical sizes and power ratings of STS.
BS EN 62310 applies to STS as a stand-alone product, whether presented as a unit or an assembly of units. It does not apply to:
- Devices for d.c. source switching
- Single source systems
- Transfer systems using only electromechanical switching devices with interruption of the supply to the load during transfer and intended to be used in emergency power systems or covered by IEC 60947-6-1
- Automatic switching devices integrated into UPS covered by the IEC 62040 series of UPS product standards.
Contents of BS EN 62310-3:
- Scope
- Normative references
- Terms and definitions
- General definitions
- Specified values
- Input values
- Output values
- Performance requirements
- Declared electrical characteristics
- Performance classification
- Main electrical characteristics
- Normal service conditions
- Transfer characteristics
- Load voltage
- Cross-current
- Neutral management
- Common neutral
- Separately derived neutrals
- Neutral current
- Protective earth current
- Performance requirements to be identified by the purchaser
- STS tests
- General
- Type tests
- Routine tests
- Site tests
- Testing schedule
- Electrical tests
- Insulation and dielectric
- Light load and functional test
- No load
- Rated load
- Transfer
- Source tolerance
- Overload and fault current
- Operating losses
- Backfeed
- Abnormal operating conditions
- Transportation and environment
- General
- Impact and shock
- Free fall
- Storage
- Temperature and humidity
- Acoustic noise
- Reference load
- STS voltage sensing tolerance
- Neutral management in static transfer systems
- Neutral switching in static transfer systems – Additional requirements
- Purchaser specification guidelines
- Output short circuit test procedure
- Backfeed protection test
- Minimum and maximum cross-sections of copper conductors suitable for connection
- Bibliography
