IEEE Std 2747-2020 pdf download

IEEE Std 2747-2020 pdf download.IEEE Guide for Energy Efficiency Technology Evaluation of Electric Power Fittings.
The distance between the current output point and its fitting should be no less than 50 times the diameter of the test conductor.
6.6 Test procedures
6.6.1 Test steps
a) The layout of the test circuit should be set up according to 6.4.
b) A test current should then be passed through the test circuit. Consult Annex B for the value of the test current. Another method is to select a certain test temperature in advance. The value and duration of the test current should be such as to raise the reference conductor temperature to the test temperature. When the conductor temperature reaches a steady state, keep constant for 30 mm. Use an initial current value not greater than 1 .5 times of the test current to provide accelerated heating to reduce testing time.
c) Measure and record data every five mm in the last 10 mm of steady state, and obtain the results by means of average values of three times measurement. When the energy loss of the fittings is too small to be measured directly, the total energy loss of the fittings and one of its connecting conductors can be measured first before the energy loss of the connecting conductors can be measured. Subtract them to obtain energy loss P, between the voltage measuring points at the two ends of the fitting.
d) Cut off the current and perform the next cycle after the conductor temperature cools to within 5 °C above ambient. In order to reduce the cooling time, forced cooling is permitted. However, uniform cooling rate should be maintained in all parts of the test circuit.
e) After the three test cycles, the energy loss of each fitting P, and the energy loss of the reference conductor P, (P, and P, are both the average of all three cycles) are calculated. The calculation method of the energy loss of fittings PiS shown in Annex A. The relative deviation of each test data from its average may not exceed 5%. Otherwise, the whole process should be resampled and retested.
The energy loss test of fittings should be carried out for three cycles. The test sequence diagrammatic form is shown in Figure 16.
7. Test and evaluation for energy efficiency of non-current-carrying electric
fittings
7.1 Sample number
The number of fitting samples should not be less than five.
7.2 Test conductor selection
The conductor used in the test should be the one for which the fitting is intended, or use annealed copper strand conductors that are agreed upon between both the supplier and purchaser. Copper rods with high purity (no less than 99.8%) can be used for the spacer test.
Test conductor should comply with the requirements as follows:
If a fitting is designed for a single size conductor, the test conductor size should be the one for which the fitting is intended.
If a fitting is designed for two or more sizes of conductor, the test conductor size should be the maximum one for which the fitting is intended.
7.3 Test conditions
Test conditions are as specified in 6.3.
7.4 Test methods
7.4.1 Temperature measurement
Temperature measurement methods are as specified in 6.4.2.
7.4.2 Current measurement
Current measurement methods are as specified in 6.4.3.
7.4.3 Voltage measurement
Voltage measurement methods are as specified in 6.4.4.
If the test sample is the spacer, the voltage measurement points should be located at current output terminals at both sides of the test assembly. Use a copper wire with a diameter of 0.8 mm +0.2 mm to tie three to four turns at the voltage measuring points. Other methods can be used as agreed upon by both the supplier and purchaser.
Power measurement methods are as specified in 6.4.5.
7.5 Test circuit layout
For layout of the test circuit, see Figure 17, Figure 18, Figure 19, Figure 20, and Figure 21. From Figure 17 to Figure 20, auxiliary test wires should be the same size as that of the test conductor, and a mechanical tension should be applied to the assembly of both fittings and test conductors to ensure it is in a horizontal state.