ASME PTC 19.6:2018 pdf free download

ASME PTC 19.6:2018 pdf free download.Electrical Power Measurements.
polarity: arrangement of test connections to a circuit that permits correct determination of the direction of power flow. In an AC circuit, power is regarded as being “delivered to the load when instantaneous current flows into the load for positive instantaneous voltage swings and out of the load for negative instantaneous voltage. Instrument transformers are marked to allow correct polarity to be maintained. In general, if the marked primary terminals are connected to a phase voltage (for a VT) or toward the generator (for a CT) and the marked secondary terminals are connected to the phase voltage or line side current terminals on the instrument, the polarity will be correct for power measurements.
powerfactor: ratio of the active power to the apparent power in a circuit; the cosine of the phase angle between sinusoidal voltage and current in an AC circuit. Power factor can never exceed 1.0.
primary winding (instrument transformer): transformer winding intended for connection to the circuit to be measured or controlled.
random error: the portion oftotal error that varies randomly In repeated measurements of the true value throughout a test process.
ratio correction Iáctor (RCF): ratio of the true ratio to the marked ratio on an instrument transformer. The primary current or voltage is equal to the secondary current or voltage multiplied by the marked ratio times the ratio correction factor.
reactive power expressed in volt-amperes reactive (var)): amount of power delivered to the reactive component of a load. Reactive components cause a phase shift between voltage and current in an AC circuit. In an AC circuit with sinusoidal waveforms, reactive power is RMS volts multiplied by RMS amps and the sine of the phase shift. (See active power and apparent power.)
secondary winding (instrument transformer): winding of a transformer that is intended for connection to the measuring protection, or control device.
systematic error: the portion of total error that remains constant In repeated measurements of the true value throughout a test process. Also called bias error.
traceable: records are available demonstrating that an instrument’s calibration has been performed against an ultimate reference maintained by the National Institute for Standards and Technology (NIST) or against a standard that Is traceable to an NIST reference.