Suitability electrical equipment

Current density can be increased without impairing the quaUty of the copper by polishing the cathode surface by brief periodic current reversals (PCR). Reversed current electrolysis, first developed for electroplating, was tested in 1952 for copper refining. Although good results were obtained, no suitable electrical equipment for current reversal was available. The thyristor-controUed siUcon rectifier, introduced in the 1960s, provided a means for... 

Many factors which affect the selection of suitable electrical equipment, such as flammable, explosive and... 

Electrical equipment suitable for a Zone 2 area (e.g. to BS 5345) and constructed to a recognized standard should be installed within the store and separation distance. Zone 2 areas are summarized in Table 9.18. 

Exception No. 5 Electric equipment suitable for ambient temperatures exceeding 40° C shall be marked with both the maximum ambient temperature and the operating temperature or temperature range at that ambient temperature. 

A recent application of this type of fluid is assistance in the removal of ingested salt spray from jet aircraft compressors and the neutralisation of corrosive effects. Other types of water-displacing fluids are claimed to have fingerprint neutralising properties or to be suitable for use on electrical equipment. Some oil-type materials serve temporarily as engine lubricants and contain suitable inhibitors to combat the corrosive products of combustion encountered in gasoline engines. 

NEC Article 501 defines electrical equipment suitable for use in Class I, Division 1 and 2 locations. Article 505 defines equipment suitable for use in Class I, Zone 0,1 and 2 locations. Mixing classification methods in a single clas-... 

Once a hazardous location has been classified, appropriate electrical equipment must be chosen for that area. In general, equipment must be approved for use in that hazardous classified area. Testing labs such as UL test, label, list, or approve equipment suitable for installation in accordance with their legislated code. 

Another kind of electrical equipment suitable for use in hazardous locations is equipment whose maximum possible energy output is insufficient to ignite the hazardous material. The electrical input to this equipment must be controlled by a specially designed electrical barrier. Such electrical equipment must be compatible. ANSI/UL913 defines low energy intrinsically safe electrical equipment and associated apparatus permitted in Division 1 areas. Nonincendive electrical equipment is permitted in Division 2 locations. Table 7-6 describes intrinsically safe and nonincendive equipment and identifies permitted uses. 

Electrical equipment suitable for classified locations can be expensive and hard to maintain. Options to using this equipment are sometimes available. These options include eliminating the hazardous materials, separating the hazardous location from the electrical equipment, moving electrical equipment outside the hazardous location, or replacing electrical operations with manual or pneumatic operations. It is frequently possible to locate much of the equipment in less hazardous or in nonhazardous locations and, thus, to reduce the amount of special equipment required. 

Equipment. Electrical equipment with a metal enclosure or with a nonmetallic enclosure listed for the use and having adequate fire-resistant and low-smoke-producing characteristics, and associated wiring material suitable for the ambient temperature shall be permitted to be installed in such space unless prohibited elsewhere in this code. 

Cross-flow filtration systems are suitable for aqueous and solvent based solutions and suspensions, provided that electrical equipment is appropriately specified to meet relevant hazardous area classifications. Most systems are... 

Harsh environments in the mines can cause electrical equipment to fail after a short time and it can be avoided by a suitable enclosure. 

Automatic tuning can be substituted for manual firequency variation. Instruments employing such frequency modulated signals have been in use for many years for measuring thickness by ultrasonic resonance. This resonance electric equipment usually does not provide a linear amplitude vs frequency readout and is therefore only suitable for the detection of resonance peaks in spectra. 

Reduced voltage systems (110 volts) are particularly suitable for portable electrical equipment in construction work and in high conducting locations such as boilers, tunnels and tanks where the risk to equipment and trailing cables is high and where the body may be damp. 

For these reasons the use of a water hose reel in factories is common and is suitable for most fires except those involving flammable liquids or live electrical equipment. 

Some sources of ignition can be discounted immediately this example, for instance, does not involve pyrophoric materials. As there are no vent lines leading to atmosphere, there is no danger from sources of ignition outside the plant. In practice, the presence of naked flames can also usually be discounted as they will normally be excluded from areas where flammable materials are handled. All electrical equipment should be checked to ensure that it is suitable for the area classification in which it is sited. 

Ensure the complete electrical isolation of electrical equipment and power supplies. Enclose all power supplies in a manner that makes accidental contact with power circuits impossible. In every experimental setup, including temporary ones, employ suitable barriers or enclosures to protect against accidental contact with electrical circuits. 

Before reconnecting electrical equipment to its power source after servicing, check the equipment with a suitable tester, such as a multimeter, to ensure that it is properly grounded. 

Most modern electronic instruments have a cord that contains a separate ground wire for the chassis and are supplied with a suitable fuse or other overload protection. Any existing instrument that lacks these features should be modified to incorporate them. As is true for any electrical equipment, special precautions should be taken to avoid the possibility that water or other chemicals could be spilled into these instruments. 

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