Testing electrical machines

Philosophy of Quality Systems and Testing of Electrical Machines... 

Philosophy of quality systems and testing of electrical machines 11/247... 

Guidelines on t ualily management and quality system elements Test code for the measurement of airborne noise emitted by rotating electrical machines Engineering method for free field conditions over a reflecting plane Survey method Determination of sound power levels of noise sources 14004/1991 BS EN ISO 9004/1994-1/1994 BS 7458-1/1991 BS 7458-2/1991 B.S 4196 9004/1987 1680-1/1986 1680-2/1986. 3740... 

Test procedure for, evaluation of system of insulating materials for random wound a.c. electrical machines. 

Philosophy of quality systems Testing of electrical machines Procedure for testing Load test No-load test Tolerances in test results Certification of motors used in hazardous locations... 

The General requirements cover apparatus grouping and temperature classification, constructional requirements for enclosures and fasteners, connection facilities and terminal compartments, cable entries and supplementary requirements for rotating electrical machines, switchgear, plugs and sockets and luminaires. A third part of the standards cover type verifications and tests as well as marking requirements. 

Rotating electrical machines shall be tested at standstill and running with 0.9X 1.0X their rated speed. The rotor causes a certain turbulence of the test gas, resulting mainly in a considerably increased dp/dt value [2] and enhanced peak pressure. Cage induction motors may be fed from outside with an adjustable voltage and frequency via a frequency convertor, motors with sliprings or commutators need an auxiliary drive, e.g. a small cage induction motor powered by said frequency convertor. 

Once the product meets all of the applicable design, component, and construction requirements detailed in the previous sections and the relevant safety standards, the electrical safety testing begins. For machinery, the subsequent sections and the relevant machine safety standards should also be met prior to testing. 

The typical electrical safety tests for machinery include, but are not limited to (see also relevant machine safety standard[s]) ... 

Currently, over 110,000 t/yr of engineering resin blends are consumed worldwide, primarily in the transportation, business-machine, hardware, electrical, and appHance industries. Annual growth is projected to be ca 17%/yr. New blends based on PC, terephthalate, and nylon resins are experiencing the greatest expansion (122). These projections could be surpassed if large-volume metal appHcations such as automotive panels are replaced by engineering resin blends which are currently being field-tested. 

The purpose of testing an electrical motor is to ensure its compliance with the norms of design, material inputs and manufacturing accuracy. It determines the mechanical soundness and electrical fitness of the machine for its electrical and mechanical performance. Such tests determine the following ... 

Routine tests are conducted on subsequent similar machines. The purpose of a routine lest is to ascertain that the machine is assembled correctly and will be able to withstand the appropriate high-voltage test, and will be in sound working eondition, both electrically and mechanically. As a minimum requirement these tests will consist of ... 

Guide for testing insulation resistance of rotating machines, rated for 1 MW and above Electrical Relays. 7816/1991 ... 

Scale-model testing is used with very large pumps such as water feed pumps for thermal power stations. The problems posed by such tests in establishing the full-size machine performance are well discussed in a paper contributed by workers studying pumps for the Central Electricity Board . 

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