Voltage maximum expected

The ratio of maximum expected voltage (E°) to thermal voltage (E°°) represents the maximum electrical work to the total available potential electrical work, the maximum thermodynamic efficiency possible ... 

The potentials from larger grounding installations on the soil surface are essentially flatter but more extended than those from overhead power line pylons (e.g., power stations, transformers and switchboard plants). The maximum expected grounding voltage in case of failure and its variation at the soil surface can be obtained from the facility s management. 

The maximum value for the peak inductor current will occur at the crest voltage of the minimum expected ac input voltage. This is... 

A comparison of typical properties of cathodic protection materials is given in Table 10.23, but is by no means comprehensive. It is obvious that the modification of an alloy, environment or other important factors will be reflected in the life and output characteristics. In some cases the maximum voltages and current densities recommended can be vastly exceeded. In others, particularly where abnormal levels of environmental dissolved solids are met, factors of safety should be applied to modify the proposed figures. Acceptance of a much reduced or uncertain life, weighed against a possible economy, may also influence the chosen working limits. For example, the life of ferrous alloy anodes may, in practice, be only two-thirds of that expected because of preferential attack eventually leading to disconnection of all or part of the anode from the source of e.m.f. 

One of the features of the Transient Analysis that causes much confusion is the Maximum step size argument in the Transient dialog box. Suppose we wish to run a circuit that has a sinusoidal source. We expect the voltages and currents to look sinusoidal, as follows ... 

The IsSpice model shows that the ramp voltage peaks at 3.7 V and has a minimum of 1.75 V. The maximum is below the extreme high specification of 4 V, and the minimum is above the extreme minimum specification of 1.4 V. This seems to line up pretty close to the data sheet, but the model s hysteresis voltage is 1.95 V, and the specified maximum is only 1.6 V. The IsSpice version of the Schmitt trigger would work for some applications where the hysteresis voltage is not so critical, but for this application, the large hysteresis value caused a much lower frequency then expected. The IsSpice model s frequency is 5.29 kHz. 

IEEE 519 also provides guidelines for maximum voltage distortion at the PCC (see Table 4.12). Limiting the voltage distortion at the PCC is the concern of the utility. It can be expected that as long as a facility s harmonic current contribution is within the IEEE 519 limits the voltage distortion at the PCC will also be within the specified limits. 

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