多少伏特以上才算是高壓電?

根據保險業界規定：
（1）高壓電是指任何帶電部份對地電壓250伏以上者；
（2）低壓電是指任何帶電部分對地面電壓在250伏以下者；
（3）爲防止觸電事故而采用的由特定電源供電的電壓系列。
這個電壓系列的上限值，在任何情況下，兩導體間或任一導體與地之間均不得超過交流（50- 5000Hz）有效值500V。

根據電業界規定：
特低壓電是指任何帶電部分對地面電壓在50伏以下者，兩導體間均不得超過交流（50- 5000Hz）有效值100VRMS；
低壓電是指任何帶電部分對地面電壓在250伏以下者，在任何情況下，兩導體間均不得超過交流（50- 5000Hz）有效值600VRMS；

中壓電是指任何帶電部分對地面電壓在3300伏以下者，在任何情況下，兩導體間均不得超過交流（50- 5000Hz）有效值6600VRMS；
6600伏特以上才稱為高壓電，高壓電塔可高達數萬伏既特高壓。
香港電力網
電力網按其在電力系統中的作用不同，分為輸電網和配電網兩種類型。
輸電網是以高電壓甚至超高壓將發電廠，變電所或變電所之間連接起來的送電網絡，所以又可稱為電力網中的主網架。低壓配電網（220V，380V電壓）。

可以到 http://www.emhk.org/index.php;學習，http://www.ats.edu.hk/eca/eeclub/Web_Study/Ch5/Ch5_sum.htm 參考http://www.ats.edu.hk/eca/eeclub/Web_Study/Ch5/Ch5_sum.htm

The definition of 'high voltage' is NOT unique, it depends on the context of the discussion. Two factors considered in the classification of a "high voltage" are the possibility of causing a spark in air, and the danger of electric shock by contact or proximity.

In electric power transmission engineering, high voltage is usually considered any voltage over approximately 35,000 volts. This is a classification based on the design of apparatus and insulation.

The International Electrotechnical Commission and its national counterparts (IET, IEEE, VDE, etc.) define high voltage circuits as those with more than 1000 V for alternating current and at least 1500 V for direct current. This is in the context of the safety of electrical apparatus.

In the United States 2005 National Electrical Code (NEC), high voltage is any voltage over 600 V (article 490.2).

Voltages over approximately 50 volts can usually cause dangerous amounts of current to flow through a human being touching two points of a circuit, so safety standards generally are more restrictive where the chance of contact with such high voltage circuits exists.

Therefore, the word 'high voltage' would have different interpretations under different applications and situations.

The above infomration is taken from the following web-page, you may have a look on it:

http://www.answers.com/topic/high-voltage-1

十萬伏特以上才算是高壓電