residual type earth-fault protection
11Protective relay — See also: Power system protection In electrical engineering, a protective relay is a complex electromechanical apparatus, often with more than one coil, designed to calculate operating conditions on an electrical circuit and trip circuit breakers …
12Geology of Mars — Mars   Mars as seen by the Hubble Space Telescope Designations …
13Nuclear meltdown — Three of the reactors at Fukushima I overheated, causing core meltdowns. This was compounded by hydrogen gas explosions and the venting of contaminated steam which released large amounts of radioactive material into the air.[1] …
14Electric shock — Electrocute redirects here. For the band, see Electrocute (band). An electric shock can occur upon contact of a human s body with any source of voltage high enough to cause sufficient current through the muscles or hair. The minimum current a… …
15Poland — /poh leuhnd/, n. a republic in E central Europe, on the Baltic Sea. 38,700,291; ab. 121,000 sq. mi. (313,400 sq. km). Cap.: Warsaw. Polish, Polska. * * * Poland Introduction Poland Background: Poland is an ancient nation that was conceived around …
16Distribution board — A fairly standard American circuit breaker panel manufactured by General Electric and using interchangeable circuit breakers A distribution board (or panelboard) is a component of an electricity supply system which divides an electrical power… …
17technology, history of — Introduction the development over time of systematic techniques for making and doing things. The term technology, a combination of the Greek technē, “art, craft,” with logos, “word, speech,” meant in Greece a discourse on the arts, both… …
18cañada — /keuhn yah deuh, yad euh/, n. Chiefly Western U.S. 1. a dry riverbed. 2. a small, deep canyon. [1840 50; < Sp, equiv. to cañ(a) CANE + ada n. suffix] * * * Canada Introduction Canada Background: A land of vast distances and rich natural resources …
19Canada — /kan euh deuh/, n. a nation in N North America: a member of the Commonwealth of Nations. 29,123,194; 3,690,410 sq. mi. (9,558,160 sq. km). Cap.: Ottawa. * * * Canada Introduction Canada Background: A land of vast distances and rich natural… …
20New Zealand — New Zealander. /zee leuhnd/ a country in the S Pacific, SE of Australia, consisting of North Island, South Island, and adjacent small islands: a member of the Commonwealth of Nations. 3,587,275; 103,416 sq. mi. (267,845 sq. km). Cap.: Wellington …
