A single-phase 240V AC motor has an input current of 4.8A. It is known that the peak voltage waveform occurs 40degrees earlier than the peak of the current waveform. Find the power-factor and the input power. Cheers =)
As the first responder indicated, the power factor value has the same numerical value as the cosine of 40 degrees. This is 0.766 The KVA input is KVA = (E * I) / 1000 KVA = (240 * 4.8) / 1000 KVA = 1.152 The definition of power factor is the ratio of KW to KVA, therefore the formula for the power input (KW) is - KW / KVA = PF KW = KVA * PF KW = 1.152 * 0.766 KW = 0.882432 TexMav
this is probable a chop up section capacitor start up motor the place all or component of the capacitance used in beginning is switched out as quickly as this is working, and that often is the 1st place i might have regarded as you have completed. The rcd score is approximately 12 cases the finished load contemporary and this would not shelter it against an overload, so it sounds like there's a fault in the motor or the feed to the motor and the only thank you to locate this is to take the circuit aside and do insulation tests on each and each piece. Intermittent faults like this are actually not straight forward to locate as while a try is finished the fault would not continually tutor.
is it difficult to calculate cos(40) with a calculator ? or are you kidding ?
