IEEE 112-2017 pdf free download – IEEE Standard Test Procedure for Polyphase Induction Motors and Generators.
The errors of the transformers used shall not be greater than ±0.5% for general testing, or not greater than ±0.3% when the test results are for use with Efficiency Test Method B. When instrument transformers and instruments for measuring voltage, current, or power are calibrated as a system, the errors of the system shall not be greater than ±0.2% of full scale when the test results are for use with Efficiency Test Method B.
4.1.4 Voltage Voltages shall be measured with the signal leads connected to the machine terminals. If local conditions will not permit such connections, the difference between the voltage at the machine terminals and the point of measurement shall be evaluated and the readings shall be corrected. The arithmetic average of the voltages shall be used in calculating machine performance from the test data.
4.1.5 Current The line currents to each phase of the motor shall be measured, and the arithmetic average value shall be used in calculating machine performance from the test data.
4.1.6 Power Power input to a three-phase motor or power output from a three-phase generator may be measured by two single-phase wattmeters connected as in the two wattmeter method, one polyphase wattmeter, or three single-phase wattmeters.
All power measurements and calculations, both electrical and mechanical, herein are in watts. On large machines it may be more practical to work with power quantities expressed in kilowatts. If the unit of measure is changed, take care that all affected values are properly converted.
4.1.7 Frequency The instrument used to measure frequency shall have an accuracy of ±0.05% of reading.
4.2 Resistance
4.2.1 Instrument selection Calibrated high-accuracy instrumentation shall be used. Either analog instruments (such as a Kelvin bridge) or digital instruments may be used in testing. The instruments shall bear record of calibration, within 12 months of the test, indicating limits of the error no greater than ±0.2% of full scale. When a suitable automatic data-acquisition system is available, it may be used.
4.2.2 Resistance measurement The procedures given in IEEE Std 118 and IEEE Std 119 should be used when measuring the resistance of the stator winding (and the rotor winding on wound-rotor machines).IEEE 112 pdf download.