What is BS EN 62689-1- Current and voltage sensors about?
BS EN 62689-1 is a safety standard on current and voltage sensors or detectors.
BS EN 62689-1 defines the minimum requirements (therefore performances) and consequent classification and tests (except for functional and communication ones) for fault passage indicators (FPIs) and distribution substation units (DSUs) (including their current and/or voltage sensors), which are, respectively, a device or a device/combination of devices and/or functions able to detect faults and provide indications about their localization.
By localization of the fault is meant the fault position with respect to the FPI/DSU installation
The point on the network (upstream or downstream from the FPI/DSU’s location) or the direction of the fault current flowing through the FPI/DSU itself. The fault localization may be obtained:
- Directly from the FPI/DSU
- From a central system using information from more FPIs or DSUs
Considering the features and the operating conditions of the electric system where the FPIs/DSUs are installed.
In BS EN 62689-1, the FPI/DSU classification is specified in detail, in accordance with the first “core” classification defined in IEC 62689-2, which is explicitly focused on the description of electric phenomena and electric system response during faults, considering the most widely diffused distribution system architecture and fault typologies.
Who is BS EN 62689-1- Current and voltage sensors for?
BS EN 62689-1 on current and voltage sensors or detectors, to be used for fault passage indication purposes is relevant to:
- Electrical engineers
- Electricians
- Manufacturers of current and voltage sensors or detectors
Why should you use BS EN 62689-1- Current and voltage sensors?
A fault passage indicator (FPI) is a device able to detect faults providing indications about their localization (upstream or downstream from the FPI’s location) and about the direction of fault current (usually referred to as the direction of load current, i.e., from the HV/MV transformer towards the end of MV feeders in a radial operated network).
The IEC 62689 series is a product family standard for current and voltage sensors or detectors, to be used for fault passage indication purposes by suitable devices or functions, indicated as fault passage indicator (FPI) or distribution substation unit (DSU), depending on their performances.
Different names are used to indicate FPIs depending on the region of the world and on their functionalities concerning the capability to detect various kinds of faults, for instance:
- Fault detector
- Smart sensor
- Faulted circuit indicator (FCI)
- Short circuit indicator (SCI)
- Earth fault indicator (EFI)
- Test point mounted FCI
- Combination of the above
Simpler versions, using only local information/signals and/or local communication, are called FPI, while very evolved versions are called DSU. Compared to instrument transformers, digital communication technology is subject to ongoing changes which are expected to continue in the future.
Profound experience with deep integration between electronics and instrument transformers has yet to be gathered on a broader basis, as this type of equipment is not yet widespread in the industry.
DSUs, besides FPI basic functions, may also optionally integrate additional auxiliary functions such as:
- Voltage presence/absence detection for medium voltage (MV) network automation, with and without distributed energy resources presence (not for fault confirmation, which can be a basic FPI function depending on the adopted fault detection method, neither for safety-related aspects, which are covered by IEC 61243-5)
- Measuring voltage, current, active, and reactive power, etc., for various applications, such as MV network automation, monitoring of power flows, etc.
- Smart grid management (such as voltage control and unwanted island operation) by means of a proper interface with locally distributed generators (DER)
- The local output of collected information by means of suitable interfaces
- Remote transmission of collected information
- Others
A general FPI scheme is outlined in BS EN 62689-1. BS EN 62689-1 provides information concerning the fault passage (local and/or remote, through lights, flags, contacts, etc.) to allow easier fault location by operators (in the field or in the network control room). Voltage sensors are used for fault current direction detection (in case of over currents, obtained with the comparison between phase current and phase voltage; in case of phase to earth faults, obtained with the comparison between residual current and residual voltage).
Overall, BS EN 62689-1 is useful as it guides on the general principles and requirements for current and voltage sensors or detectors, to be used for fault passage indication purposes which can be beneficial for your business.
