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phase converters

Single-phase power can be obtained from any three-phase electrical system by connecting any two phase leads. However, it is not possible to obtain three-phase power from a single-phase power source without recourse to either a rotary or static phase converter A rotary phase converter is a machine that can convert single-phase power to three phase …

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what is voltage regulator

All of the components in an electrical system are designed to operate at their rated voltages for optimum efficiency and long service. An ideal electrical system would provide constant voltage to all customers under all conditions of load. Unfortunately, because of the unpredictable dynamics of a practical system, none is ideal. Thus, it is necessary …

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nec branch circuit requirements

The National Electrical Code (NEC 2002) provides guidance for electrical contractors and electricians, but it is really intended for use by governmental agencies that have legal jurisdiction over electrical installations and authorized electrical and insurance inspectors. The many mandatory chapters include Chapter 2, “Wiring and Protection,” Chapter 3, “Wiring Methods and Materials,” and Chapter 4, …

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Electrical Boxes

NEC 2002, Article 314, “Outlet, Device, Pull, and Junction Boxes; Conduit Bodies; Fittings; and Manholes,” requires that wire connections or cable splices be contained inside approved metal or plastic boxes. This provision is intended to shield wood building framing members or other adjacent flammable objects from electrical sparks should the wiring be defective. Boxes also …

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metal and nonmetallic conduit

Indoor metal and nonmetallic conduit can keep dust and moisture out of wiring and protect it from mechanical abrasion. Short sections can protect wiring close to the floor used to power washing machines and clothes dryers in damp basements. These sections must be anchored to masonry walls where there are no wood studs for supporting …

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Wire Insulation and Cable Coding

INSULATED WIRE CODING The wire manufacturers’wire markings give: Wire gauge Maximum voltage rating Insulation code (R for thermoset, T for thermoplastic, X for cross-linked polyethylene thermoset) Maximum temperature code (H for 75°C, HH for 90°C, nothing for 60°C) Abbreviation for sheath if present (e.g., N for nylon) The identification codes for wires with thermoplastic insulation …

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