3000W at 120V is 25 amps. He had better have a dedicate circuit. I believe if I had to run a dedicated circuit I would run a 220 circuit for the amp and put everything else on the UPS.
--------- KQ5S-Tom > On Aug 30, 2017, at 6:42 AM, Don Wilhelm <[email protected]> wrote: > > Bret, > > The power rating of a transmitter is the output power, not the input draw. > > If the overall efficiency is something like 33% (quite likely), then the > input draw will 3 times the output power. > The efficiency of an RF output stage alone is typically about 50%, but there > are other circuits in the transmit section that must be added and brings the > overall efficiency of the transceiver down even more. > So yes, the input power required is about 3 times the output power. > > A KPA500 running on 120 volts just about maxes out a 15 amp circuit, and that > is 1800 watts input. The K3 will need about 300 watts additional. > That means your UPS should be rated at least 2500 watts, but 3000 would be > more reasonable because it seems you have other gear in the ham station that > needs to be supported as well. > > 73, > Don W3FPR > > On 8/30/2017 7:16 AM, MaverickNH wrote: >> As mentioned in another thread, I'm running my shack on a UPS that is rated >> 1500va/900w. With my K3S/100 and other hardware plugged in on the same input >> the UPS often max's out at 900W at < 100W on the K3S. Typically, the >> baseline with K3S on RX is ~350W and it spikes over 900W with TX at 100W and >> the UPS limits output. So it seems 100W isn't 100W. >> I'm looking to switch in another UPS rated 2200VA/1320W, or 420W higher, for >> use with the KPA500/KAT500 I just acquired from another forum member. so >> from a 100W station to a 500W station. Might this work or is the increase in >> watt TX not equal to the watt drawn? > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
