Phase wire

Macroshock, or simply electric shock, describes simultaneous contact between the body surface and two electrical conductors at different potentials, and the physiological consequences of this contact. The two conductors maybe a hot conductor and ground, or two hot conductors, such as two of the phase wires in a three-phase power distribution system. 

Residual voltage The vector sum of the voltages in all the phase wires of an unbalanced polyphase power system. 

These results correspond to those given in Table 1.1 for the 500 kV transmission line shown in Figure 1.25. Because a phase wire is composed of four bundles, the analytical results are four times the internal impedance given in the table. The analytical results agree weU with those in the table, which are calculated using the accurate formula in Section 1.2.1 (Equation 1.9). 

FIGURE 1.25 An untransposed vertical twin-circuit line, (a) Line configuration, (b) Phase wire. 

When lighming strikes a tower (or a GW) as illustrated in Figure 2.36, the lighming current flows into the tower and causes a sudden increase in tower voltage. When the voltage difference between the tower and a phase wire (PW) reaches its electrical withstand voltage, a flashover from the tower to the PW occurs. This is called back flashover (BFO), because... 

In Figure 6.17, TRN-TRNB is a grounding lead of the transformer represented by a lossless distributed line (the surge impedance is explained in Reference 32). is the grounding resistance of the transformer grounding lead, and its values by utility are provided in Table 6.11 [25,26]. PW represents a phase wire of a distribution line and is modeled by a lossless distributed line with the surge impedance Zp = 530 Q. The other end of PWl is terminated by the matching impedance Zp. ... 

Impingement demister systems are designed to intercept liquid particles before the gas outlet. They are usually constructed from wire mesh or metal plates and liquid droplets impinge on the internal surfaces of the mist mats or plate labyrinth as the gas weaves through the system. The intercepted droplets coalesce and move downward under gravity into the liquid phase. The plate type devices or vane packs are used where the inlet stream is dirty as they are much less vulnerable to clogging than the mist mat. 

Thermal Conductivity Detector One of the earliest gas chromatography detectors, which is still widely used, is based on the mobile phase s thermal conductivity (Figure 12.21). As the mobile phase exits the column, it passes over a tungsten-rhenium wire filament. The filament s electrical resistance depends on its temperature, which, in turn, depends on the thermal conductivity of the mobile phase. Because of its high thermal conductivity, helium is the mobile phase of choice when using a thermal conductivity detector (TCD). 

When a solute elutes from the column, the thermal conductivity of the mobile phase decreases and the temperature of the wire filament, and thus its resistance, increases. A reference cell, through which only the mobile phase passes, corrects for any time-dependent variations in flow rate, pressure, or electrical power, ah of which may lead to a change in the filament s resistance. 

Alloys. Alloys consist of two or mote elements of different vapor pressures and hence different evaporation rates. As a result, the vapor phase and therefore the deposit constantiy vary in compositions. This problem can be solved by multiple sources or a single rod- or wire-fed electron beam source fed with the alloy. These solutions apply equally to evaporation or ion-plating processes. 

Welding (qv) of titanium requires a protected atmosphere of iaert gas. Furthermore, parts and filler wire are cleaned with acetone (trichloroethylene is not recommended). The pieces to be welded are clamped, not tacked, unless tacks are shielded with iaert gas. A test sample should be welded. Coated electrodes are excluded and higher purity metal (lower oxygen content) is preferred as filler. Titanium caimot be fusion-welded to other metals because of formation of brittle intermetallic phases ia the weld 2oae. 

Rates and selectivities of soHd catalyzed reactions can also be influenced by mass transport resistance in the external fluid phase. Most reactions are not influenced by external-phase transport, but the rates of some very fast reactions, eg, ammonia oxidation, are deterrnined solely by the resistance to this transport. As the resistance to mass transport within the catalyst pores is larger than that in the external fluid phase, the effectiveness factor of a porous catalyst is expected to be less than unity whenever the external-phase mass transport resistance is significant, A practical catalyst that is used under such circumstances is the ammonia oxidation catalyst. It is a nonporous metal and consists of layers of wire woven into a mesh. 

Conveyor Motors Motors for conveyor drives are generally three-phase, 60-Hz, 220-V units 220/440-V 550-V four-wire, 208-V. Also common are 240- and 480-V ratings. Although many adjustable-... 

Applying this law to a three-phase, three wire. system,... 

When a three-phase four-wire system feeds non-linear or single-phase loads this balance is upset and the unbalanced current flows through the neutral. The same relationship can be expressed as... 

---