BS/EN 14908-3-2014 pdf download.Open Data Communication in Building Automation, Controls and Building Management Control Network Protocol Part 3: Power Line Channel Specification.
This clause gives several recommendations related to safety concerns with respect to this European Standard.
This discussion is not complete. nor does it address all possible safety issues. The designer is urged to consult, among other things. the relevant local and national electrical codes for the country of intended use, Local codes may supplement national electrical codes and impose additional safety related requirements.
Products conforming to this European Standard shall be designed, constructed, assembled, tested and installed following recognised safety provisions appropriate to products covered by the standard.
Power line network cables are subject to at least five direct electrical safety hazards during their use:
• high-energy transients coupled into the power line network from external environmental sources;
• possible differences between safety grounds to which network components are connected:
• possible high voltages on neutral or ground wiring;
• possible open safety grounds:
• high short-circuit current levels available at interface.
These electrical safety hazards should be alleviated for the network to pertorm properly, in addition to provisions br properly handling these faults in an operational system, special measures should be taken to maintain the intended safety features during changes of an existing network.
All wire and wiring to which nodes connect should Conform to wiring standards of the appropriate national code for the country of intended use and should have been inspected to comply with that code.
4.2 Functional partitioning of PL specification
This specification divides the complete power line environment into two basic parts: the powerline medium and the node physical access specification.
The medium specification concerns the capabilities and properties of the physical medium. This encompasses such items as its bandwidth, frequency allocation, electrical and physical specifications, connectors etc.
The node physical access specification deals with the physical properties of that part of the node that makes contact with the medium. Also described is the interface between the physical layer and the symbol-encoding sub- layer.
5 Power Line Medium specifications
5.1 Power
The nodes should not rely on the line frequency for timing or synchronisation to perform communications. AC
power may be used to power the interface and application needs of a node.
5.2 Data channel
The channel occupies bandwidth from 125 kHz to 140 kHz frequency band, as defined in EN 50065-1, as a Binary Phase Shift Keyed (BPSK) modulated carrier. This channel is used to send protocol messages containing control, status, configuration and diagnostic information. The rules established in the CNP Medium Access Control (MAC) Layers and above shall be followed. The signalling characteristics of the channel are described in Clause 6.
5.3 Physical and electrical specifications
Physical and electrical specifications for the PL medium are not formally given in this European Standard since: 1) the PL medium is assumed to already exist in any environment using power line communications and: 2) this specification lacks control over the installation of the power line medium, Its physical properties, topology, or other devices connected to the medium.
5.4 Connectors and coupling
If a connector is used to attach a CNP node to the power line network (as opposed to a direct connection), then the connector shall meet the following requirements:
• the connector shall impose a negligible signal loss (less than 0,1 dB) from the power line network and the attached node;
• the connector shalt not impose any signal or voltage loss (greater than 0,1 dB) to the power line network (with or without a node connected to the connector).
Single-phase power line node connectors are assumed to fit standard electrical outlets appropriate for the country of use and may or may not include a connection to the protective conductor of such outlets if present. BS/EN 14908-3-2014 pdf download.