Recent content by QwertyXP

Hello I have to conduct factory inspections of Polyethylene pipe / fittings manufacturers on behalf of my company. The PE products are to be used in natural gas pipeline network. In order to check conformance to relevant standards / best practices, I have prepared a set of questions to ask...

Thanks, Doug Huffman. But how would we size the solar panels?

Many suppliers of solar systems give power ratings in terms of kW. However, how should I size the system for loads whose PF is not unity? I am specifically concerned about the solar panels. Should the panels' kW rating be matched with the load's kVA rating? Thank you

Please have a look at the following links: http://www.eaton.com/ecm/groups/public/@pub/@electrical/documents/content/sa02607001e.pdf (Table 3) http://www.electrical-installation.org/enwiki/Power_factor_correction_of_induction_motors FigL24) - For power factor correction, why would the...

But the tiny current was sufficient to make the tester glow quite brightly - about as bright as you see when you're standing on ground with no shoes!

I had a 4:1 single phase step-down transformer. Primary winding was provided the mains supply (225V) and output (secondary) was 57V. I was under the impression that capacitive coupling b/w primary and secondary was noticeable only in high-voltage transformers, and thus in this case (low voltage)...

Why does a voltage tester (that looks like a screwdriver) turn on even when you are "heavily" insulated from the ground e.g. sitting on a wooden chair. Is it the result of capacitance between the human body and the ground? (i.e. the body and the ground act as conductors, whereas the insulated...

neutral terminal of step-up's secondary was earthed The "load" consists of current flowing through step-down's primary winding, which is not even connected to the earth. So how can fault current travel through the Earth and back to step-up's neutral terminal? as well as transformer's metal...

I observed the following configuration in a factory: Power supply from a generator (400 V line-to-line) is stepped up to 11 KV (line-to-line), which is then fed to another transformer that produces a stepped-down, 2-phase output. The step-down transformer has 3 input terminals. Step-up...

Our electrical workshop received a complaint that the motor's overload relay was tripping (motor didn't burn up though). Upon inspection, the electrician discovered that two of the phases had higher currents. I'm assuming that currents were normal when the motor was installed because...

A 3-phase induction motor in our factory had unequal phase currents. One of the currents was nearly normal while the other two were about twice the usual value. Somebody said that prolonged running causes increase in resistance of stator winding, and this results in increased current. But this...

I don't remember much about Q. Yes, if power factor is unity and the load is purely inductive, we have a resonant circuit. I had the understanding that at resonance, capacitor provides only as much reactive power as is required by the inductor. But now, looking at it from a different...

I am looking for an explanation of why over correction of inductive loads can result in large circulating currents. Many sites give some form of vague verbal description but I have not been able to comprehend this phenomenon. Can anyone explain it mathematically or provide a link that...

Got it, thank you.

When you connect a capacitor across an inductive load, reactive power (Q) flows back and forth between capacitor and inductor, so (ideally) the generator doesn't need to supply Q to the load. My question is, why doesn't the capacitor supply Q to the generator as well? If only a capacitor were...