Power frequencies voltages

Power frequency voltage withstand level, according to Section 14.3.3 and... 

Verification of dielectric properties, limited to power frequency voltage withstand or HV test on power as well as control and protective circuits. 

One-minute power frequency voltage withstand at any frequency between 45 and 65 Hz (between phases and ground)... 

Wet test While an indoor type switchgear assembly requires only a dry power frequency voltage withstand test, the outdoor type switchgear assembly also needs a wet test under wet conditions to check the external insulation. For the test procedure refer to lEC 60060-1. 

C = lumped capacitance of the lower voltage side = prospective voltage surge on the primary side /) = a factor to account for the power frequency voltage already existing w hen the surge occurs... 

For non-effectively grounded systems, having a GFF of more than 1.4, a higher level of insulation (BIL) will be essential for all equipment being used on the system to withstand a higher level of a one-minute power frequency voltage test as well as an impulse voltage withstand test if such levels (Lists I, II and III) are prescribed in the relevant standards. If not, then it may be assumed, that the prescribed test values take account of such an... 

The above tests refer to dry power frequency voltage withstand tests for indoor units. Outdoor capacitor units will be subjected to a wet test as in lEC 60060-1. 

Nominal system voltage Rated max. system voltage One-minute power frequency voltage withstand at a frequency between 45 and 65 Hz for LT and 25 and 100 Hz for HT systems Standard lightning impulse, 1.2/50 fis voltage withstand (phase to ground)... 

Field tests (power frequency voltage withstand) after erection at site, if required, may be conducted at 85% of the values indicated above in LT and 80% in HT systems. 

Table 32.1(B) For series I voltage systems Power frequency voltage withstand levels for metal-enclosed bus systems...

Nominal system Rated maximum One-minute power frequency voltage Standard lightning impulse One-minute d.c. 

For a power frequency voltage withstand test a d.c. test is generally not recommended on a.e. equipment, unless only d.c., test voltage is available at the plaee of testing. The d.e. test values, as above, are therefore for such eventualities only and are equivalent to power frequency a.c. voltage withstand test values. 

These are generally the same as the routine tests. No field test as regards the power frequency voltage withstand or HV lest is normally prescribed on a bus system, which has already been tested at the manufacturer s works. Repealed application of high voltage may deteriorate the insulating properties of the insulation system and its life unless modification has been carried out at site or where the insulation of joints between the busbars can be completed only after erection at site. In such cases, if this test becomes essential it can be conducted,... 

Power frequency fields fall in the category of super low frequency (SLF) fields and are generated by the fundamental power frequency voltage and currents and their harmonics. Because of the low frequency content, these fields do not easily interact with other power, control, or signal circuits. Power frequency electrical fields do not... 

Wet power frequency voltage flashover (Horizontal) 11.71kV... 

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