Voltage readings on 13.8KV

[lex1969]

Hi
I am new to HV and doing an apprenticeship, can someone please explain what Voltage I would expect to find when testing on 13.8 KV and 3.3 KV with Seaward Voltage Sticks, I have been told 13.8KV would read 7.9Kv and 3.3Kv would read 1.9Kv but  can someone explain please who this is worked out??, thanks

[Mads Barnkob]

When measuring on 13.8 kV and 3.3 kV, I would expect 13.8 kV and 3.3 kV. I am not familiar with high voltage testers or the Seaward sticks.

The lower numbers you gave does not even make sense from a Peak/RMS perspective, so I am not sure how those numbers are derived unless its from the measurement equipment specifics?

[Phoenix]

Is it a 3 phase system? If the 13.8kV is considered as the line to line voltage then the line to ground voltage which the stick measures will be 13.8/sqrt(3) which is around 7.9kV.

[Mads Barnkob]

Is it a 3 phase system? If the 13.8kV is considered as the line to line voltage then the line to ground voltage which the stick measures will be 13.8/sqrt(3) which is around 7.9kV.

Thats the answer! single phase to neutral in a 3 phase system.

I only tried with sqrt(2) for the peak/RMS, should have tried with sqrt(3) as well