Good Morning.
Hopefully i can get some suggestions here…though may be completely wrong forum. If so - my apologies in advance.
I’ve recently installed a portable home generator and after reading a ton of posts, apparently many of these portable generators can produce very high THD which according to many of the posts I’ve read…can damage electronics over time.
There are many videos available which show how to measure and calculate the harmonic distortion with a scope using a Fourier transform but after being out of technical school for (30+ years) isn’t a real option for me ( also don’t have a scope). There are power analyzer meters out there which can return a THD % result but are ungodly expensive and simply out of reach to a home owner…even if they did have the knowledge to calculate the THD.
I was wondering if anyone knew if any of these inexpensive hand held scopes might have an automatic THD % algorithm built in? I know these are probably just for hobbyist but if i could find one that has an auto calculation i’d certainly consider it.
For reference…i’m thinking of units like the SainSmart DS212…or the LM2020, …or the Thsinde TH944…all just over a hundred dollars.
Hopefully something out there for the avg homeowner!
I have never come acrossed a THD algorithm, but I know that most new electronics won’t be affected by 9% THD. Almost all now use switching supplies that first rectify incoming line voltage and turn it into DC. This is then switched into a small transformer and then rectified again to the final lower voltage. Feedback circuit controls high side switching to regulate output.
I own many generators and rarely need one to run my home. I am still a little perplexed with this new craze to have a whole house generator. How long is you power outage going to be. Mine are usually a few hours and rarely a few days. put in a wood stove instead. The only reason I could justify a whole house generator is if I had a basement that floods. And that could be run with a portable one. Or maybe if you have elderly folks in the house that may need oxygen etc. I would never connect any of my electronic to ANY generator, properly connected or not. Electricity seems pretty simple, hot leg, neutral and ground. Nothing to it. NOT so, neutral bonding, grounding etc these are very serious issues. Whatever you do, absolutely have it inspected by the nys electrical inspector. Don’t take some local electricians word. file for the permit it may save your life.
Thanks for the reply.
I’ve been looking at a program that uses a sound card for the input as a digital oscilloscope. No luck so far getting it to work but I’m hopeful as the programmer has been making some mods to try and use it in this application.
I’ve lived in northern Canada with -40 temps and worked away from home most the time. My initial generator was simply installed to run my natural gas furnace in the event of a power outage. With a wife and small kids at home it was a great piece of mind.
When we moved to Houston….it was the power outages that lasted a week or more due to hurricane damage that prompted me install a system large enough to run a central AC. Some folks down in Louisiana lost their power for up to 4 weeks after tue last hurricane blew through ….again. It’s the ACs they are looking to run……so many are also looking at large generators.
In my case I’m simply interested in just how much THD these output. I’m not honestly worried but have a keen interest.
Cheers.