- In this episode of Cranes 101,
we're gonna take a look at Variable Frequency Drives,
and how they changed the entire overhead crane game.
(upbeat music)
What's up guys, Devon here from Mazzella Companies,
and today we're doing a deep dive
into Variable Frequency Drives.
In this video, we'll cover: what a VFD is,
and how it's used, what are the Components that make it up
and what kind of problems can it solve,
and then we'll wrap up by talking about
the importance of transparency between you and the operators
as they transition, or start over,
with their new Variable Frequency Drive system.
To help me tell this story, I reached out to Jon Schafer,
who's job title is kind of a mouthful.
So he is a Manufacturer Rep for Magnatek Material handling,
and he joined me via teleconference to really just start
by unpacking what a Variable Frequency Drive does
and why they became so popular.
(gentle music)
- Well, a Variable Frequency Drive, or VFD,
came out really in the late 80s and early 90s.
And the reason that they came out and became so popular
is because the cost came down, they became cost efficient.
What they do for us, just like the name sounds or says,
Variable Frequency Drive, we're able to vary the frequency
to a AC motor and by varying the frequency,
we're able to get motor control out of it.
I'm saying motor control, being able to adjust the speeds,
being able to adjust acceleration and deceleration ramps.
- So as Jon said, a VFD System really just
gives you control over whatever you apply it to.
Hoist or trolley, bridge or hook,
it really depends on what you want to control.
And before that, you were just at the mercy of your motor,
single speed, two speed it really just depended
on what you had or the complexity of the crane.
But how much did the VFD system
really change the way that you operated?
- Once the Variable Frequency Drive came in,
now we are able to give you performance
similar to almost DC, but with just
a single-speed squirrel cage motor.
So, single-speed squirrel cage motor,
simplest motor on the market, or available,
and by using Variable Frequency Drive, we can control
how fast the motor accelerates, how fast it decelerates,
and we can also control speed points.
- So, sounds like an awesome piece of tech.
But how exactly does the VFD System work?
- What a Variable Frequency Drive does,
is it creates a sinusoidal wave
by varying the voltage and frequency,
to trick an AC motor into think
it's at a synchronous speed even when it's not.
(gentle music)
The one that really got the thing
on the map was a minimizing brake wear.
Let's say your contactor-controlled trolley, right?
The guy's beating the button, bang, bang, bang, bang, bang,
trying to get motor control out of it, right?
Well every time he does that, when he lets go of the button,
we use a mechanical brake to stop the motion.
Whoo, whoo, whoo, eventually the thing wears out,
you put in some application to a guys plug in a lot,
he might only get months, maybe even weeks
out of the brake and the brake's wearing out.
- So for me, having a new system in place
that helps to save my brakes and keep my maintenance team
from having to replace it all the time, is pretty valuable.
But there had to be some other perks, right?
- We also have adjustable accel and decel times.
So you can set, let's say your bridge
is 300 feet per minute, you might want that
to accelerate in five or six seconds,
or your trolley might be 100 feet per minute,
you might want to accelerate that in three seconds.
You know, one of the examples we often talk about
is NASA loading Space Shuttles
or satellites into the Space Shuttle.
That crane might do, you know, I don't know,
120 feet per minute on the bridge,
but when they got a satellite on there,
they're in no hurry, they don't care if it takes all day
to get that satellite into that Space Shuttle.
(gentle music)
- So, now that we know what a VFD system is, how it works,
and the problems that it can solve,
I wanted to know about the transition for operators
from an old system to a new VFD system.
So if it's so easy, it's gotta be a breeze, right?
- That, if there is a disadvantage, that is probably it.
In the old days, they were able to abuse the controls.
They were able to get the crane to kind of,
well, do whatever they want right now.
The shortfall is, now the operator says,
"hey, I'm used to stopping at 300 feet in three feet,
"now it takes me eight or ten."
So there is a learning curve with operators.
The biggest problem I've had, in my experience,
is working with operators that have been doing this
for 30 years and expect them to operate one way
and then it changes.
- Now, I'm the type of guy that likes complete control
over the systems that he uses.
I have my keyboard mapped out the way I want it.
I have my cellphone laid out the way I want the apps to go.
And I wondered that when it comes
to Variable Frequency Drives, what control
does an operator have, because if I was an operator
I would want to do the same thing
to get it dialed in exactly how I want it.
So I asked Jon, what control does an operator have
to get their VFD systems dialed in
exactly the way that they want?
- It's all there, you know what I mean?
The keypad's there, the book's there, it's all online.
If they wanted to figure it out, they could.
I've rarely seen, I think of only once,
an operator actually getting out there and changing things.
- The last thing I wanted Jon to explain to me
was when a VFD system will work the best,
because I've been working this industry long enough
to know that not everything works for every application.
And I was actually pretty surprised
to find out the sheer range of when
a VFD system can work and work great.
- At first, it only made sense to do it
on high-speed, Class D and E bridges, or this and that.
Now it's, you know, you're buying a five ton shaw box
and it's got a little tiny inverter on the trolley.
I mean, it's just all the time now.
And manufacturers now are even using it
to match speed requirements
rather than changing gear box sets.
(gentle music)
- Hopefully we were able to give you a better understanding
of how Variable Frequency Drives work.
And the cool thing is, you don't
have to stop here with this video.
If you want to hear the full conversations
that Jon, myself, and our Content Manager, Mike Close, had,
If you have Itunes, Spotify, Soundcloud, or Stitcher
all you gotta do is go to your favorite one
and search Mazzella Companies and look up
our Variable Frequency Drives podcast.
You'll hear the full episode,
the entire conversation without any edits whatsoever
to learn as much as you possibly can.
If you like this video don't hesitate to check out
the rest of our Cranes 101 Series,
or The Rigging Professor as well.
There's a ton of content there
and we're gonna make a whole bunch more this year.
In addition to that, if you haven't already,
Subscribe to the channel,
and there's a little notification bell that you can ding
so anytime I upload a video, you see it first.
At Mazzella Companies, we have a team of highly-trained,
Lifting Specialists who want nothing more than
to meet with you and talk about your next lifting project
and what that best application could be.
Maybe it's Variable Frequency Drives, maybe it's not.
But the best thing you can do,
especially if you're not sure, is to reach out
to one of our Lifting Specialists
who would be happy to help you however they can.
And hey, if you're not sure what kind of overhead crane
you need, why don't you learn everything you can about it?
If you click the link above, it'll take you to a resource
that we developed just for you.
Download the free Overhead Cranes E-Book.
It's "Overhead Cranes from Top to Bottom."
It doesn't cost you anything whatsoever.
Our goal, as always, is just to make sure
that you are as trained as possible
before you buy anything at all.
For all of us at Mazzella Companies, I'm Devon McCarty.
Thank you for watching.
(gentle music)