Volt drop

As the current increases due to the presence of organic vapor, the voltage drop across the linearizing resistance also increases and reduces the voltage across the electrode. For example if 1300 volts is applied to the detector and when a solute is eluted, the current increases to 10" amp, this will cause a 300 volt drop across the linearizing resistance of 3 x 10 and consequently reduce the voltage across the electrodes to 1000 volts. In this way the natural exponential response of the detector can be made sensibly linear. 

Each reactance and resistance in the machine has a volt drop associated with it due to the stator current flowing through it. Consider a generator. The following currents and voltages can be shown in a phasor diagram for both the steady and the dynamic states. 

These equations can be transposed to find Xf, Xm and Xkq in terms of X, X J and X" in particular. The purchaser may require certain limits to Xj and X J because of constraints on fault currents and volt drop. Consequently the machine designer is faced with finding physical dimensions to satisfy the resulting X d, Xf and X. The purchaser is not usually too concerned about the quadrature parameters. Transposing (3.1), (3.2) and (3.3) gives the designer the following -... 

Assuming 100% voltage at the switchboard or motor control centre, the volt-drop at the motor terminals should not exceed the following guidelines -... 

LV cable volt-drop when running at full-load 2.5% to 5.0%. 

Appendix G gives detailed calculations of cable volt-drops for the starting and full-load running conditions of a 500 kW induction motor that is to be started direct-on-line in a power system that is fed by three 3125 kVA generators. This appendix demonstrates the following aspects of starting large motors -... 

Currents now exist in both windings. Therefore a volt-drop must exist in each winding due to its leakage reactance (due to leakage flux) and its conductor resistance. The equivalent circuit of a single-phase transformer can be represented as in Figure 6.2. 

Regulation is a subject that regularly occurs in power systems. Regulation is a measure of the voltage drop in a device or circuit. It compares the volt-drop at fuU-load with the terminal voltage at no-load, both of which can be obtained for a transformer from simple factory tests. 

Note See Chapter 9 for a similar expression used with cable volt-drop). 

The nsual limit to volt-drop in three-phase cables feeding static loads is 2.5% at full load. 

Route length is short and volt-drops are negligible for starting and running. 

The conductors are usually copper or aluminium. Aluminium is seldom used in the oil industry because it work hardens during installation, has higher losses, has high volt-drop at rated current and requires special attention during termination. 

Volt-drop developed across the cable under steady state and transient conditions. 

The secondary cable runs on its own cable rack to a switchboard. Both cable routes are short enough to neglect volt-drop considerations. Find suitable Cu/XLPE/PVC/SWA/PVC cable conductor sizes. 

The volt-drop AV is normally considered as a per-unit or percentage quantity with respect to the sending end line-to-Iine voltage V, therefore -... 

Since the volt-drop is less than 20% the motor will accelerate to full speed without difficulty. 

The volt-drop in the left-hand side of the cable is Vsc,... 

The receiving end volt-drop with respect to the nominal system voltage is Ay ,... 

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