Wiring enclosures

The report mentions neither a date nor a place. It is claimed that the Jews were driven on foot from barbed-wire enclosures to an unknown destination, but not that they were murdered at the outskirts of Kyiv . 

During March 1996 major Ukrainian newspapers reported that Ukrainian American historians determined that the Jews were deported from Babi Yar via the nearby military railroad station to Minsk. During the stay behind barbed wired enclosures, Germans allegedly extracted from the Jews the customary war tax in valuables.10... 

Mathis and Smith (1992) pioneered an excellent trap experiment technique for studying the responses of freshwater littoral fishes to chemical alarm cues. Mathis and Smith s experiment, and most of those that followed, used Gee s Improved Miimow Traps, roughly cylindrical wire enclosures (43 cm length x 22 cm diameter) with a funnel located at each end leading into the trap. Cube-shaped artificial cellulose sponges saturated with the experimental treatment were threaded onto stainless steel wire, and... 

Main incoming Power Supply Metering panel, HT transformer, barbed wire enclosure ... 

Other types of wiring circuits and wiring enclosures are discussed in detail in Chapter 3. 

In industrial appHcations it is not uncommon that the thermocouple must be coupled to the readout instmment or controUer by a long length of wire, perhaps hundreds of feet. It is obvious from the differential nature of the thermocouple that, to avoid unwanted junctions, extension wine be of the same type, eg, for a J thermocouple the extension must be type J. Where the thermocouple is of a noble or exotic material, the cost of identical lead wine may be prohibitive manufacturers of extension wine may suggest compromises which are less costiy. Junctions between the thermocouple leads and the extension wine should be made in an isothermal environment. The wine and junctions must have the same electrical integrity as the thermocouple junction. Because the emf is low, enclosure in a shield or grounded conduit should be considered. 

Electrical Applications. Plastics are used for electrical insulation, conduit and enclosures, lighting fixtures, and mechanical devices. The most widely used plastic for wire and cable insulation is flexible, plasticized PVC, which constitutes well over half the market in insulating wires for buildings, automobiles, appHances, and power and control lines. Polyethylene is also a factor. Higher performance plastics such as nylon and fluoropolymers also play a smaller role in this area. 

Explosion-proof enclosures are characterized by strong metal enclosures with special close-fitting access covers and breathers that contain an ignition to the inside of the enclosure. Field wiring in the hazardous environment is enclosed in a metal conduit of the mineral-insulated-cable type. All conduit and cable connections or cable terminations are threaded and explosion-proof. Conduit seals are put into the conduit or cable system at locations defined by the National Electric Code (Article 501) to prevent gas and vapor leakage and to prevent flames from passing from one part of the conduit system to the other. 

Protection against contact with live or moving parts inside the enclosure by tools, wires or objects having a thickness greater than 2.5 mm. 

To fulfil the above requirements the material inputs for the motor, such as stampings, steel, enamelled copper wire, insulations and varnishes, bearings, enclosure materials and hardware must be subjected to a series of acceptance tests according to norms and standard specifications. For example, enamelled copper wire used... 

The test is carried out with a steel wire of 2.5 mm diameter. The wire should not go through the enclosure. 

This test is applicable to all outdoor metal-enclosed switchgear and controlgear assemblies, as in lEC 60298, lEC 60694 and ANSI C-37/20C. The enclosure to be tested should be complete in all respects including its mounts, bushings (for HT switchgear assemblies, 1 kV and above) and wiring. One or more vertical units can be tested simultaneously as may be convenient, but not more than 3 m panel width can be tested at a time. For a multiple unit switchboard, however, at least two vertical units should be tested together to check the joints between the units. 

Inspection of electrical wiring if there is any (such as for space heaters, cold or hot air blowing, enclosure pressurizing or any other protective circuit)... 

Certain devices may be obtained which are factory-sealed —that is, interconnecting wiring is sealed by the manufacturer where it enters/exits enclosures. These devices do not require an additional (external) seal, and often can be utilized to advantage in lessening installation time and reducing space requirements (for an external seal). 

Although transformers suitable for other industrial installations are generally suitable for producing applications, certain options may be desirable— primarily due to environmental considerations. At locations subject to harsh environmental conditions, and particularly at locations subject to washdown with high-pressure hoses, non-ventilated enclosures are desirable, if not necessary. Likewise, at locations subjected to salt water and salt-laden air, it often is desirable to specify copper windings and lead wires. Most manufacturers provide standard units with aluminum windings and lead wires. Even if aluminum coils are used, it is almost always desirable to require stranded copper lead wires. This will lessen corrosion and loose terminal problems when transformers arc interconnected to the facility electrical system with copper conductors. If the transformers are to be installed outdoors in corrosive environments, cases should be of corrosion-resistant material (e.g., stainless steel) or be provided with an exterior coating suitable for the location. 

After an area classification has been established, then anelectrical equipment, instruments, and wiring must adhere to that classification. Therefore, some motor enclosure types would not be electrically acceptable for specific area classifications. 

Figure 11-17 Establish a Good High-frequency AC Connection to the Enclosure at the Output-end of Power Supply by Means of Thick Braided Wire...

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. 

The vacuum-tube diode, invented by Fleming24 in 1904 [2,3], works because of the relative geometrical shapes of the two concentric electrodes, the cathode and the anode. It consists of a cylindrical glass enclosure that is partially evacuated, bonded, and sealed to a metal base. It contains an inner metallic thin-wire "cathode" (negative electrode, consisting of W, oxide-covered W, or a Th-W alloy), placed along the cylinder axis. This cathode is electrically heated to 900 K or above, using an auxiliary filament circuit, typically driven by a 6.3-V power supply, to foster thermoionic emission of electrons from the cathode. This cathode is cylindrically surrounded by a metallic outer electrode, the anode or "positive electrode" or "plate," which is a hollow metallic cylinder, whose axis coincides with that of the cathode. The... 

---