Hi, I had an electrician who wired emergency shut down of a big computer room from blue print. When test time came after completing the wiring, I pushed big red button, nothing happened. Ooops! nothing went down. This so called licensed electrician couldn't even read simple relay logic mixed with 24V and 120V control circuits. I had to tell him what to do. Maybe this guy is his brother or co-worker. This kind of folks are trouble makers in the field. I am retired but I still keep my basic knowledge. I don't invent or bend rule of physics. Tony
Hi, Which is power factor of 1(phase angle is aero). No loss circuit. Pure resistive load which does not hardly exist in real world. Cos0(zer degrees) = 1. Thanks, Boden. Tony
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ That's the key here. Thank you for saying it, prepare to be belittled and badgered by those too simple minded to understand.
It most certainly will trip, given time. That's the whole purpose of the NEC requirement to limit a continuous load to 80% capacity.....prevent nuisance tripping.
I've installed plenty of them. Try a synchronous condenser some time. _DO_ tell me the _correct_ required wire size (THWN) for a 100 kVAR capacitor bank connected to a 3 phase 277/480 volt Wye connected system........that is, if you know how to calculate amps for the given kVAR.
Tell me one pure inductive load in any utility grid.
That works two ways don't ya know. I've seen plenty of stamped and signed blueprints that were not correct......everybody makes mistakes. A shunt trip is soooooooooo hard to wire, huh Tony? _DO_ tell us how the HVAC shutdown and the fire dampers were incorporated into the deal.
Make me wonder how _you_ managed to get on top of last year's list of AHR's "Who's Who of Useless Posters."
Geez, you sure about that Tony? _DO_ tell us how that "air" core resulting from coiling the ni-chrome wire for the incandescent lamp filament creates that overwhelming inductance. Funny how the engineers and other professionals who write the NEC consider inductance to be insignificant when making calculations for resistive loads......or is it just that they are morons too?
The only simpletons here are the morons like you who insist that the minuscule amount inductance in an incandescent lamp somehow becomes a significant factor when calculating the VA of a resistive load. Tell us again, Tomi Boi, how is it that you came to the conclusion that a toaster is an inductive load and a vacuum motor is a capacitive load?
Yes, be prepared to be belittled. Incandescent Lights are indeed near perfect resistive loads and as far as I kow they do exist in the real world.
Electric water heaters (and to a lesser degree dryers), near perfect resistors, their job is to dissipate heat. Yes, if you are running an air conditioner or fridge yes, there will be 10-15% reactive portion. High crest factor current waveforms (in electronics) can also impact usable power on a given breaker, but this is well beyond the scope of the question. The question in this case will can ten 65 watt bulbs be safe off a 15 amp circuit and the answer is yes, by more then factor of 2.
Furthermore cos(phi) is an oversimplified for PF. Total power (real + reactive) is the integral of the product of the voltage and current. The current in many electronics devices being nonsinusoidal. Finally, mathamatics is the TOOL quantify the PHYSICS in this problem. Circuit breakers do not do math, they do follow the laws of PHYSICS. Now that you have been belittled by someone simple minded perhaps you will not post that which you are ill informed on.
I had a 15 amp breaker that tripped when the load was 20 amps (that's what I calculated, with computers, TV, lights and a 1100 watt blowdrier). I asked the electrician about it and he said breakers trip at different currents, depending on how long they stay at that current. since a breaker works by heating, it will take let's say 10 seconds to trip at 20 amps and maybe a minute to trip at 17 amps, but yes, if left at 15 amps constantly it will trip after a while because it heats up.
then you know that engineering is based on approximations. at RF frequencies the inductance can't be ignored, but for a power engineer, at 60 hertz, the load is purely resistive. the difference between 6 ohms and 6.0003 is irrelevant in this context.
^^^^ ^^^^^^^ So you admit that they are not a pure resistive load. Thank you for the confirmation. I snipped your rant, as it was no help in proving your point. If you had a point, that is.
Thanks for proving that the simple minded are indeed reading the newsgroup, I knew the proof would be offered by someone.
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