Variable Frequency Drives and Inverters

[@crazy8051controller]

You people are doing a wonderful job. Hvacschool is becoming a benchmark for hvac enthusiasts.

[@borshardsd]

"If your meter says zero, you're probably about to get shocked" M. Taylor 😂 couldn't agree more! Thank you guys for the content. Great job.

[@ayoutubewatcher7009]

Ghost voltage is real

[@rob8823]

Great topic! Thx

[@Nine_883]

Aaon units use a pretty sophisticated Freq drive for the blower.

[@BloominOnion1]

Thanks for the video. fascinated at 37:36. We have a lot of overseas jobs where the line voltage is 50 Hz. I suppose a VFD could convert the 50 Hz signal and give us an output 60 of Hz for our standard equipment. Any concerns with this? I guess bypassing the VFD (or VFD malfunction) would still make that inadvisable? Cool presentation.

[@brianmcdermott1718]

Great Tech. info. Great people to. Thank you Bryan.

[@vocalpatriot]

Having a working hot water heater is better than having to de thaw the pipes……😏

[@Nine_883]

In DC electronics capacitors can be wired to increase voltage. Careful guys. It might sound off topic, but in electronic circuits…….

[@ShanQueefus]

All i know is vfd's break down all the time.

[@Nine_883]

That’s a fact. They fault out often. Nuisance trips. Intermittent trips are common. This also depends on the quality of your power supply. If you get a lot of phase losses and things like that you will have a lot of failures.

[@ayoutubewatcher7009]

As someone who started, commissioned and warrantied Vfd’s for 6 years. This is 100% inaccurate. Although 10-15 years ago I would have agreed, today absolutely not.

[@Nine_883]

Mosfets. Just like an a standard DC electronic speed controller on an electric bike.

[@Nine_883]

EEV’s are becoming cheaper to manufacture. I work in R&D for a commercial supermarket manufacturer. Tighter control? Maybe theoretically, but some of these valves (stepper valves) do not control good at all. Cheap manufacturing in China. They should control better, but it’s only as good as the quality of the manufacturer and the quality of the code that was written to drive these valves. Sporlan EEV works best with their controller. It depends on your support and your microcontroller. You could make them work fantastic with an Arduino if you were good enough at writing the sketch.

[@darrellcooper1640]

I'm not tech, but I enjoy watching this channel and learning about HVACR. Funny and informative. I'm 46 and this channel has me convinced to leave my office job and try my hand at something useful. Great job!

[@rj.parker]

Technically AC to DC is a “Converter” while DC to AC is an “Inverter”. Obviously changing 60 cycle AC to DC is simple and is something any electronics hobbiest or tech can do and understand easily. While a rectifier (diodes these days) and a big cap produces DC with ripple, adding an inductor and high frequency small caps reduces the ripple making the DC power useable for most applications. A three phase “inverter” to drive motors is actually three separate inverter circuits all drawing from the same DC power. Each inverter circuit is driving its own motor winding. Creating a variable frequency / voltage waveform CAN be very accurate, eg a sine wave inverter. For driving sensitive loads you want a sine wave inverter, sometimes driven by generators with somewhat inaccurate speed control. For variable speed or constant torque motors pure sine wave outputs are not optimum. These vfds or ecms have specifically designed waveforms to achieve torque when needed or to produce efficiency most of the time. Achieving reliability in power electronics used in poor environments is the real challenge especially for low cost applications. Clearly in industrial applications where cost is less of a factor a Vfd can be installed in a clean situation and cooled with better strategies.

[@ayoutubewatcher7009]

I have to say. This channel has gotten my attention. I don’t think young techs understand the knowledge and experience you are sharing. I needed the refresher, thank you. I know drives can be intimidating, especially the larger hp rated ones, but in the end, they all follow the same principals and accomplish the same thing. This is where the industry is, regardless of what you specialize in the field. Actually I find it easier to work on compared to the equipment in the 90’s and early 2000’s.

[@peterlarsen6940]

The freak you're talking about is spelled freque