Short-circuited line

5 Voltages and Currents on a Finite Line 1.3.5.1 Short-Circuited Line 

Substituting the earlier condition into Equation 1.52, the unknown constants C and D are determined as 

The impedance of fhe finife line seen from fhe sending end is given as a funcfion of fhe line lengfh 1  

Using fhe relafionships sinh)x=y sin x and cosh)x = cos x, fhe solufions of fhe volfage and fhe currenf are expressed as 

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FIGURE 1.13 Z(/) - 0 characteristic of a lossless short-circuited line. 

In a similar manner to a short-circuited line, the solutions of voltage and current are obtained in the following forms ... 

Figure 1.16 shows the relationship between Z 1) and 0 = jLCi lossless line. As for a short-circuited line, the relationship coincides with Foster s reactance theorem. The line is in a resonant condition for 0 = (2n - l)7t/2 n positive integers, as in Equation 1.103. 

Short-circuited line A short-circuited line with an incoming wave e(x - ct) as in Figure 1.38a is equivalent to an infinite line with e(x - ct) and -e(x + ct). 

A short-circuited line, (a) Short-circuited line, (b) Equivalent circuit. 

In a submerged-tube FC evaporator, all heat is imparted as sensible heat, resulting in a temperature rise of the circulating hquor that reduces the overall temperature difference available for heat transfer. Temperature rise, tube proportions, tube velocity, and head requirements on the circulating pump all influence the selec tion of circulation rate. Head requirements are frequently difficult to estimate since they consist not only of the usual friction, entrance and contraction, and elevation losses when the return to the flash chamber is above the liquid level but also of increased friction losses due to flashing in the return line and vortex losses in the flash chamber. Circulation is sometimes limited by vapor in the pump suction hne. This may be drawn in as a result of inadequate vapor-liquid separation or may come from vortices near the pump suction connection to the body or may be formed in the line itself by short circuiting from heater outlet to pump inlet of liquor that has not flashed completely to equilibrium at the pressure in the vapor head. 

Line Starters and Combination Starters A line starter consists of a contactor (motor-starting switch) and motor-overload relays, (Contactors are capable of canving and interrupting normal motor-starting and -running currents they are not, hovv ever, normally capable of interrupting short-circuit currents. They must be backed up by fuses or a circuit breaker for this function,... 

While connecting a delta-wound motor through a Y A starter, the metallic shorting links should be removed. Otherwise the starter will have a dead short-circuit at the motor terminal box and may burn the starter, damage the motor terminal box and even line cables. 

Interrupting the equipment such as an induction motor, a transformer, a cable or an overhead line on a fault, such as on a short-circuit or a ground fault. 

A CT is provided in series with the spark gap to sense its operation during a line fault. As soon as there is arcing, it provides an instantaneous command to a short-circuit relay. The relay, in turn, closes the bypass breaker, within 3 to 5 cycles, leaving only the natural line impedance in the faulty eircuit. Now = 0, which limits the fault current to the natural level of the system, as if the capacitors were not connected. The shorting device is restored to its original status as soon as the fault condition is cleared. The device must be capable of interrupting the line fault... 

Inductive interference the production of electrical potentials in conductors due to the induction from alternating magnetic fields arising from short-circuit currents or operational currents in high-voltage power lines. 

The field strength, E, induced by grounding short-circuit currents in high-voltage overhead power lines or railway power lines, is basic in calculating the pipeline potentials (see Section 23.3.2). The field strength, E, follows from Refs. 2 and 13 ... 

The continuous BD line should be found in the drum above the first gas pass (the hottest part of the boiler), at a point before the BW mixes with FW, but away from the FW line to avoid short circuiting. 

The short-circuiting or taking the least line of pressure resistance of a flow of water in a resin bed. 

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