Windings Delta

When employing such a switching method precautions should be taken or provision made in the starter to ensure that the windings are switched ON to delta only when... 

Heat generated in a delta-connected stator winding... 

Figure 12.9 Stator and line currents on single phasing for a delta-connected winding...

Figure 12.10 Current magnitudes in different phases of a delta-connected stator winding and rotor during single phasing...

When the primary of a three-phase two-winding transformer, having its secondary wound for a three-phase open delta, is connected across an unbalanced supply system, a residual voltage across the open delta will appear. This is the principle on which this transformer is based (Figure 15.4(a)). As discussed in Section 21.2.2, and illustrated in Figure 21.7, the phasor sum of all the three line to ground voltages in a three-phase balanced system is zero, i.e. 

A delta-connected or an ungrounded star-connected winding should also be protected through a restricted ground fault scheme, otherwise it will remain unprotected. There is no zero sequence or residual current in such a winding to detect a ground fault. 

Star/delta or auto-transformer switching of a motor For motors compensated individually and having a star/ delta or auto-transformer switching, the changeover from star to delta windings or from one step of the auto-... 

A new gin for ginning spindle-picked cotton was constructed in the Mississippi Delta in 1977. The layout of the machinery, doors, and waste collecting system was designed to reduce worker and community exposure to airborne dust by optimizing functional area locations with respect to the prevailing winds from the southwest and northwest. Dust levels were measured in this gin (16) during the peak of the ginning period in 1979, and were found to be ... 

During the low-flow periods and under the influence of the eastern winds, seawater can penetrate into the deep delta channels [8]. The maximum length of seawater intrusion recorded during recent decades was 16.5 km in the Sulina branch [29] and 14.0 km in the Ochakovskiy branch [8]. As a rule, seawater penetrates into the delta branches in the form of salt wedge . 

The mixing zone of river fresh water with salinity less than 0.5%o and sea brackish water with salinity up to 18%> occupies a bend up to 20-30 km in width during high-flow period and western winds and of 3-5 km during the low-flow period and eastern winds [7,30]. The Danube water spreads mainly on the surface with layer from 1-3 to 5 m [9]. The Danube River water runoff and its distribution between delta branches play a very important role not only in hydrological and hydrochemical regime of the delta and mouth nearshore zone but also in formation of ecological conditions in the northwestern part of the Black Sea as a whole [7,9,30]. 

Hydrological and hydro chemical regimes of the delta and especially of the liman are mainly determined by the river fresh water inflow, local climatic conditions, including wind regime, and water exchange between the liman and the sea through the outlet. 

For fluorescein angiography a properly equipped fundus camera must have a high-intensity flash system combined with a rapid recycle time, power winding, appropriate excitation filters (the Baird Atomic B2 470 or Kodak Wratten 47), and barrier filters (an Ilford 1109 Delta Chromatic 3 or Kodak Wratten G15).Both excitation and... 

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