Megger PPX30, User Manual, Page: 79 / 84

Appendix C — Recommended Test Voltages
Recommended DC Voltages for Insulation Resistance Test
EASA AR100 and IEEE 43 sections 5.4 and 12.2 provide guidelines on voltage to be applied during Insulaton
Resistance (IR) testing. Test voltage should be applied for one minute.
Table 20: Recommended DC Voltages for Insulation Resistance test: EASA AR100 and IEEE 43.
Winding Rated Voltage (V)* Insulation Resistance Test Direct Voltage (V)
<1000 500
1000–2500 500–1000
2501–5000 1000–2500
5001–12,000 2500–5000
>12,000 5000–10,000
* Rated line-to-line voltage for three-phase AC machines, line-to-ground for single-phase machines, and rated direct
voltage for DC machines or filed windings.
Recommended DC HiPot and Surge Test Voltages
Megger Baker Instruments has a recommended standard (see table) for test voltages for DC tests and Surge tests
conducted on a motor, generator, or transformer. That standard is twice the AC line voltage plus 1,000 volts.
This test voltage is consistent with NEMA MG-1, IEEE 95-1977 (for test voltage greater than 5,000 volts) and IEEE 43-
2000 (test voltages less than 5,000 volts).
View other standards in the tables below for a comparison of IEEE 95, EASA AR100 DC-HiPot, IEEE 522 Surge testing,
IEC 34-15, and Megger recommended testing voltages.
NOTE: The tables list representations of motors, as well as the formulas to calculate voltages so that you can
calculate test voltage of any size motor.
Table 21: IEEE 95 for HiPot test.
V Line Per Unit Min Test,
V Line × 1.25 × 1.7 Max Test,
V Line × 1.5 × 1.7
480 392 1,020 1,224
575 469 1,222 1,466
600 490 1,275 1,530
2,300 1,878 4,888 5,865
4,160 3,397 8,840 10,608
6,900 5,634 14,663 17,595
13,800 11,268 29,325 35,190
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