Category Archives: Three phase motor starting

Power factor correction

Energy efficiency was, is and will be one of the major topics of interest for modern society. In absolutely any industry, regardless of field of activity every company aims, through the products they sell, how they consume less power and offer higher performance as well. Power factor is one of those factors that can seriously…
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Star-Delta starting

Protection with thermal overload relay Operating mode: When the Start button is pressed star contactor Q2 coil is energized. It closes and by means of normally open contact of Q1 the voltage is applied to main contactor Q1. Q1 closes and supplies the voltage to motor M1 in star connection. Q1 and Q2 are maintained via…
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Three phase motor connected to single phase power supply

fig.1 Delta connection               It happens quite often that three phase motors to be connected to single-phase voltage. This does not present a great connection problem, only problem really important is the energy consumption, because these motors efficiency will decrease. If is a low-power motor and is rarely used that…
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Direct On Line (DOL) starting

Protection with thermal relay Operating mode: By pressing Start push button the Q1 contactor coil is energized, the motor will start run and maintains itself after the button Start release, by means of auxiliary Q1 contact, the Stop button and and thermal relay 97-98 normal close contact. When overload occur thermal relay 97-98 normal close contact opens, so the motor is stopped. Thermal relay…
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