FAQ
Surge Test Voltages and Standards
This page describes the three main standards used for surge test voltages. To learn more about how the iTIG is used for surge comparison tests, see Surge Test Summary and Surge Test Methods.
Electrom surge testers meet the requirements of these three main standards that are used for surge test voltages:
Note that the standards presented here are recommendations only. Any voltage can be agreed upon between the parties involved (such as the device maintainer and device owner). If there are any concerns, the voltage should be reviewed by those involved.
For a summary containing tables, graphs, and recommendations, see Summary and Recommendations.
Surge Test Voltage Standard Recommendations Followed by Electrom
Summary and Recommendations of Voltages to Use
The following graphs and tables show the differences between the recommendations in the standards.
Electrom Instruments Recommendations for Surge Tests of Machines
For Used Machines
Use the ANSI/EASA formula. The low surge test voltage for IEEE at lower operating voltages will result in fewer weaknesses being found, especially for inverter driven motors.
All the standards mention that the surge test formulas do not take inverter drive spikes into account, and that a higher surge test voltage may be considered for inverter applications.
Industrial users will sometimes de-rate surge test voltages down to the line to line RMS rated voltage for machines that are in operation, especially for those considered to be ‘dirty’. A test voltage lower than the peak operating voltage equal to RMS x 1.41 Volts, will not cover the whole operating voltage range of the motor. Although a de-rated surge test voltage can be prudent at times, it will not provide information about problems to come unless it is higher than the peak operating voltage.
For New Machines
Use the ANSI/EASA formula for machines with operating voltage of 1,000V or less.
Use either standard for higher voltages. The higher IEEE voltages for machines operating above 1,000V are still far below what the machine should be able to handle.
Keep in mind that Surge and Hipot tests should not be done if the insulation resistance megohm measurement does not support it. Click here for more information.

Surge Test Voltages (V) for Maintenance of Used Machines | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|
RMS Line-to-Line Voltage | 460 | 575 | 1,000 | 2,300 | 3,300 | 4,160 | 6,600 | 11,000 | 12,000 | 13,800 |
ANSI/EASA AR100-2015: Random and form wound machines: V=2*E+1000 | 1,920 | 2,150 | 3,000 | 5,600 | 7,600 | 9,320 | 14,200 | 23,000 | 25,000 | 28,600 |
IEEE 522-2004: Form coil wound machines: V=2.86*E*75%=2.15E | 986 | 1,232 | 2,143 | 4,930 | 7,073 | 8,916 | 14,146 | 23,576 | 25,720 | 29,578 |
Surge Tests of Form Coils
The options for testing form coils are many, and the standards address the subject differently.
IEC differentiates between sample coils that are surge tested before installation in the stator (bench test), and coils installed in the stator but not connected yet. The bench test of sample coils embedded in earthed slots or fitted with the slot portion wrapped in earthed conducting tape or foil, is at a much higher voltage than tests done on coils installed in a stator. IEC does not address testing of installed coils that are connected, or completed machines.
Sample testing and testing of all coils after manufacture should not be compared. They are two different types of tests. Once the coils are installed in the stator, the surge test voltages for the two standards are more similar. Installed in the stator, many users will also apply the ANSI/EASA formula which is in the same range as the IEEE and IEC formulas.
Electrom Instruments Recommendations for Surge Tests of Form Coils
The user should agree with the manufacturer of the form coils what surge test voltages to use.
There are many different insulation materials and technologies, and each may require different test voltages at different stages of production of a machine.
IEEE does not discuss bench testing of sample coils, but covers bench tests of all coils after manufacture, surge tests of coils at different stages of machine production, and tests of complete machines.


Surge Test Voltages (V) for New Form Coils | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|
RMS Line-to-Line Voltage | 460 | 575 | 1,000 | 2,300 | 3,300 | 4,160 | 6,600 | 11,000 | 12,000 | 13,800 |
IEEE 522-2004, New fully cured coils: V = 2.86*E | 1,315 | 1,643 | 2,858 | 6,573 | 9,431 | 11,888 | 18,861 | 31,435 | 34,293 | 39,437 |
IEEE 522, Unimpregnated coils: 60-80%, 70% used here | 920 | 1,150 | 2,000 | 4,601 | 6,601 | 8,322 | 13,203 | 22,005 | 24,005 | 27,606 |
IEEE 522, Uncured resin rich coils: 40-60%, 50% used here | 657 | 822 | 1,429 | 3,286 | 4,715 | 5,944 | 9,431 | 15,718 | 17,146 | 19,718 |
IEC 60034-15-2009, New sample coils not installed in stator: V = 0.65(4E+5000) | 4,446 | 4,745 | 5,850 | 9,230 | 11,830 | 14,066 | 20,410 | 31,850 | 34,450 | 39,130 |
IEC 60034-15, New coils installed in stator before processing/connections: 40-80%, 60% used here | 2,668 | 2,847 | 3,510 | 5,538 | 7,098 | 8,440 | 12,246 | 19,110 | 20,670 | 23,478 |