Effectively grounded systems

Continuous An effectively grounded system Between line and ground... 

Grounding conditions Whether an isolated neutral system, an effectively grounded system or a non-effectively grounded neutral system ... 

Solid neutral grounding system (also known as effectively grounded system) 20/664... 

It is also established that in an effectively grounded system the voltage to ground, Vg, of the healthy phases does not exceed 80% of the line-to-line voltage V( and consequently the GFF does not exceed 0.8 x I3, i.e. 1.4. The. system may be considered as effectively grounded when... 

For non-effectively grounded systems, having a GFF of more than 1.4, a higher level of insulation (BIL) will be essential for all equipment being used on the system to withstand a higher level of a one-minute power frequency voltage test as well as an impulse voltage withstand test if such levels (Lists I, II and III) are prescribed in the relevant standards. If not, then it may be assumed, that the prescribed test values take account of such an... 

This is to achieve a higher level of fault current to obtain a quicker tripping on fault. It is obtained when the system has a ground fault factor not exceeding 1.4 (Vg < O.SVf), as noted above. A solidly grounded system will provide effective grounding. This system will reduce the transient oscillations and allow a current sufficient to select a ground fault protection. It is normally applicable to an LT system. 

It will also depend upon the condition of system grounding, i.e. whether cfl ectively grounded, non-effeclively grouned or isolated neutral etc. For systems other than effectively grounded, list 2 must be preferred. 

A program to ensure that a well-designed and effective electrical earth-grounding system and equipment bonding system is in place is an essential first step in... 

As with transmission analysis, DRIFTS test samples are generally ground and mixed with an IR transparent salt, such as potassium bromide (KBr), prior to sampling. However, to ensure that there is no catalytic effect, most systems use CaF2 or powdered crystalline carbon (diamond). One drawback is the presence of reststrahlen bands whose contrast can be reduced by... 

Fig. 1. The adiabatic potentials (AP) in the Jahn-Teller (a), Renner-Teller (b), and pseudo-Jahn-Teller (c) effects for systems with a double degenerate electronic term interacting with one coordinate Q (E bi problem in the JT case). In all three cases the ground state is unstable in the high-symmetry configuration <2 = 0, while the stable configurations at Q0 are at lower symmetry. The differences between these cases are in the behavior of the AP at Q = 0.

The linear photoresponse of metal clusters was successfully calculated for spherical [158-160, 163] as well as for spheroidal clusters [164] within the jellium model [188] using the LDA. The results are improved considerably by the use of self-interaction corrected functionals. In the context of response calculations, self-interaction effects occur at three different levels First of all, the static KS orbitals, which enter the response function, have a self-interaction error if calculated within LDA. This is because the LDA xc potential of finite systems shows an exponential rather than the correct — 1/r behaviour in the asymptotic region. As a consequence, the valence electrons of finite systems are too weakly bound and the effective (ground-state) potential does not support high-lying unoccupied states. Apart from the response function Xs, the xc kernel /xc[ o] no matter which approximation is used for it, also has a self-interaction error. This is because /ic[no] is evaluated at the unperturbed ground-state density no(r), and this density exhibits self-interaction errors if the KS orbitals were calculated in LDA. Finally the ALDA form of /,c itself carries another self-interaction error. 

For the purpose of evaluating the energy W of the ground State, the variation method is effective. A system of identical atoms will be treated by this method in detail that of unlike atoms will be noted briefly at the end of the section. A theorem will be-first shown. 

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