IEC 60688 pdf download Electrical measuring transducers for converting a.c. electrical quantities to analogue or digital signals
This International Standard applies to transducers with electrical inputs and outputs for making measurements of a.c. electrical quantities. The output signal may be in the form of an analogue direct current or in digital form. In this instance, that part of the transducer utilized for communication purposes will need to be compatible with the external system.
This standard applies to measuring transducers used for converting alternating electrical quantities such as:
– active power
– reactive power
– power factor
– phase angle
to an output signal.
Within the measuring range, the output signal is a function of the measurand. An auxiliary supply may be needed.
This standard applies:
a) if the nominal frequency of the input(s) lies between 5 Hz and 1 500 Hz;
b) if a measuring transducer is part of a system for the measurement of a non-electrical quantity, this standard may be applied to the electrical measuring transducer, if it otherwise falls within the scope of this standard;
c) to transducers for use in a variety of applications such as telemetry and process control and in one of a number of defined environments.
This International Standard is intended:
– to specify the terminology and definitions relating to transducers whose main application is in electrical power engineering, especially for the purposes of process control and telemetry systems;
– to unify the test methods used in evaluating transducer performance;
– to specify accuracy limits and output values for transducers.
2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60521 :1 988, Class 0,5, 1 and 2 alternating-current watt-hour meters
IEC 61 000-4, Electromagnetic compatibility (EMC) – Part 4: Testing and measuring techniques
IEC 61 01 0-1 :2001 , Safety requirements for electrical equipment for measurement, control and laboratory use – Part 1: General requirements
NOTE Refer to annex A for the list of informative references.
For the purpose of this International Standard the following definitions apply:
3.1 General terms
electrical measuring transducer (hereinafter designated “transducer”)
a device for converting an a.c. measurand to a direct current, a direct voltage or a digital signal for measurement purposes
an a.c. or d.c. electrical supply, other than the measurand, which is necessary for the correct operation of the transducer
a circuit which is usually energized by the auxiliary supply.
NOTE The auxiliary circuit is sometimes energized by one of the input quantities.