Technical specifications – General
There are international and national standards, as well as customer specifications. ABB High Voltage Products can meet most
requirements, as long as we are aware of them. When in doubt,
please enclose a copy of your specifications with the inquiry.
The system voltage is the maximum voltage (phase-phase),
expressed in kV rms, of the system for which the equipment is
intended. It is also known as maximum system voltage.
Rated insulation level
The combination of voltage values which characterize the
insulation of an instrument transformer with regard to its capability to withstand dielectric stresses.
The rated value given is valid for altitudes ≤1000 m above sea
level. A correction factor is introduced for higher altitudes.
Lightning impulse test
The lightning impulse test is performed with a standardized
wave shape – 1.2/50 µs – for simulation of lightning overvoltage.
Rated Power Frequency Withstand Voltage
This test is to show that the apparatus can withstand the
power frequency over-voltages that can occur.
The Rated Power Frequency Withstand voltage indicates the
required withstand voltage. The value is expressed in kV rms.