EECO Asks Why Podcast

158. Short Circuits and Overloads: What's the Difference?

October 10, 2021 Electrical Equipment Company Season 6
EECO Asks Why Podcast
158. Short Circuits and Overloads: What's the Difference?
Show Notes Transcript

Protection of electrical circuits can be tricky to understand.  Jonathan Fuller is an expert in these devices and breaks down how to differentiate between short circuit and overload protection.  He points out that it starts with understanding what the upstream potential is that could damage the equipment from a huge inrush of instantaneous current.  The short circuit device is the equipment that springs into action in these instances and can save end users a lot of headache, damage and potential downtime when configured correctly.

As equipment runs the loads can vary.  Sometimes the mechanical load varies or there can be other items that impact the current of the load.  When that happens knowing how to select and configure an overload device can add significant run life to the assets. 

Jonathan unpacks the different types of load classes for the devices and even gives some advice for those that run into the "just turn the overload up" situations to keep production moving.  Technology is changing fast in the world of circuit protection and this idea episode is designed to connect the dots for anyone in industry.  To have a circuit that you can have confidence in takes proper design of both short circuit and overload protection - take the steps now to ensure the equipment meets your expectations of production, reliability, and safety. 

Guest: Jonathan Fuller - Automation & Power Product Manager at Electrical Equipment Company (EECO)

Host: Chris Grainger
Executive Producer: Adam Sheets
Podcast Editor: Andi Thrower

Short circuit protection and safety evaluation 
Short circuit protection or overload protection overview 

00:00 Jonathan: 

You're going to need both because they do separate things. And there's new technology out there every day and new types of devices. Do your research and be diligent on it. And if you need help, that's kind of what we're here for at EECO to be able to help you select the right types of devices to help protect your circuit and your facility. 

00:17 Chris: 

EECO Asks Why a podcast that dives into industrial manufacturing topics, spotlights the heroes that keep America running. I'm your host, Chris Grainger. And on this podcast, we do not cover the latest features and benefits on products that come to market, instead, we focus on advice and insight from the top minds of industry because people and ideas will be how America remains number one in manufacturing in the world. 

All right. Welcome to this episode of EECO Asks Why. Today, we're going to be digging into a topic above short circuit and overload protection. What's the difference and why does it matter? So joining us today, we have our automation and power product manager, Mr. Jonathan Fuller with us from South Carolina. So Jonathan, just to kick us off. What's the main difference in short circuit and overload protection? 

01:08 Jonathan: 

Hey Chris, thanks for having me. One of the biggest differences between the two is an overload is going to be long durations of over current on the device. Whereas short circuit, it's going to be that quick high hit of over current that can cause some major issues in your device. 

01:25 Chris: 

Okay, very good. So Jonathan, when I think of short circuit and overload protection, I go back to my experience working in the repair days. And I can even take this to a mechanical failure, it's not just electrical, where a good friend of mine, Mr. Mark Latino taught me to different difference of a brittle failure. So let's talk a little bit deeper here. Why should the end users care and understand the differences between the two protection schemes? 

01:53 Jonathan: 

They're going to provide different protections for different areas of their scheme. So the short circuit protection that's gonna be usually in the means of a circuit breaker or a fuse, and that's going to be upstream of that overload and motor. So that's going to protect that your wire and your motor and your overload from those high, huge inrush currents, really quick hits, but the overload device is there to protect the motor and the wiring between the overload and the motor. So the overload is not really gonna pick up those in rush currents are not going to care about the inrush current.

It's more there for over time as that motor has too much load on it. It's going to be there to shut that down so that you don't damage your motor with things like heat and cause issues in the motor was that overload protection. So they're really, they're two different things, but you need both in that circuit.

02:43 Chris: 

And just for the listeners out there, because your motor tripped on overload does not necessarily mean that you need to go crank your overload up some right? 

02:53 Jonathan: 

Right. So, I mean, those overloads they've got different classes in there for different types, class 5, 10, 20, different types of trip curves and things like that. And a lot of them are going to have that built-in reset so that if you do trip out that motor, that motor tripped for a reason. Most times we're just wanting to go back and hit that reset and get it up and running as quickly as we can, but that actually can cause a lot of damage to that motor because of the heat in that motor and can cause issues with your bearings and things like that. So they're going to have that built in reset so that you can't just go slam that reset button and get up and running. And you're going to have to wait a little bit for that motor to cool. 

03:27 Chris: 

Very good. So let's think about common mistakes. We're here to help people to help industry out there. What are some of the common mistakes you hear about from end-users in regards to short circuit or overload protection? 

03:41 Jonathan: 

Chris, you brought up a great point just a minute ago that if my motor's out there tripping, let me just go increase the overload or the short circuit protection on it. That's not always a smart idea. In fact, it's usually never a smart idea because it's tripping for a reason and it was designed to do what it's doing. So if you go and increase that amperage you could potentially cause a safety issue and things could catch on fire, or you could have an event at your facility and that's not ever something that you want to deal with. 

And also, you know, a lot of times people do the same with short circuit protection, like a breaker, if my breakers tripping, I can't tell you the amount of times I've heard people say, yeah, we'll just pull that 20 amp breaker out and put a 30 amp in and that'll fix it. Chances are, if you do that, a lot of your devices that, that circuit breakers protecting, or, the wire that it's protecting, they're not rated for that higher current. So while your breaker's not tripping, Hey, that's great for you. It could cause your wire to melt or it could cause a fire in your facility. So you really need to be careful about sizing your short circuit and your overload protection for the job at hand.

04:42 Chris: 

That's a great point. Safety is always a key, element of what we talk about on EECO Asks Why. So that's a great tie back Jonathan that you did there from that sizing standpoint, because you're right. The conductors, the cables that are out there that are run to the equipment are designed for those ratings. And if you exceed that, you could be opening yourself up to a potential problems. So let's talk a little bit more here on this topic. What do you see as an area where people potentially are cutting corners that could be impacting them in the future when it comes to short circuit overload protection?

05:19 Jonathan: 

Yeah, a lot of times I see people just not really use overload protection, they might just use their short circuit and then their device, like their drive or their starter without overload to try and save some money or undersize the device, or if the device breaks they're overload or they're short circuit protection breaks, they might just not replace it and bypass it to get out there and keep running. There's several different types of overload, relays and things out there like that. And they've all got their different pros and cons, a lot of times facilities are running on the cheapest possible protection that they can just so they can get by and, make a dollar.

05:55 Chris: 

So is price. One of the main resistant points that our end users are facing right now, because obviously we're trying to keep costs down at a plant? Do you see that as is one of the primary areas of resistance? 

06:09 Jonathan: 

Yeah, absolutely. Everybody's got a budget. Everybody has a target they've got to hit. So when you go into a facility and say, "Hey, Mr. Customer, here's some new technology and things that are safer and better." A lot of times they're like how much does it cost? And then when you start talking about things like that, they're like, yeah, no, I can't do that. My budget. And I'm getting fine just by on what I'm doing now. Be it might be something that they've had to bypass or something that's not safe and doing what they need it to do, but it's working for them now. So they're not wanting to spend that money and that budget to try and upgrade to something that's better and safer.

06:41 Chris: 

Absolutely. How about applications, so far is a resistance that end users are seeing. Do you see any of that out there? 

06:49 Jonathan: 

Yeah, sometimes you know, as technology changes and things like that. What they might've been doing a couple of years ago is now there's better ways out there to do it, but again, it comes back to it's been working for 10 years and that device might not have a 10 year life history so why change it now? I'll worry about it when it breaks. A lot of times people aren't wanting to change anything unless it's broken. 

07:10 Chris: 

What about the ability to learn from things that failed right in the plant? So is there a way that we can look at failed components and maybe evaluate new ways or new technology out there to give us a better protection in the future?

07:26 Jonathan: 

Yeah. That's one of the best ways that people learn about things is the failures that have happened. We can go in there and look at your current protection scheme and how you've got things set up and learn from that. If it didn't work, why didn't it work and what can we do to make it better and use some of the newer technology or things out there to help them get a better set up to help them in the future.

07:47 Chris: 

Absolutely. Good advice. But just in closing and wrapping up, do you have any advice or takeaways that you had that would you offer up to our end users so they can remember that would be impactful for them when it comes to short circuit overload? 

08:03 Jonathan: 

Yeah. There, there is a difference between the two and a good protective circuit is going to have both in it. You're going to have a short circuit protection and, a breaker or a fuse upstream, and then you're going to have your overt protection downstream where your starter and motor are. You're going to need both cause they do separate things. And there's new technology out there every day and new types of devices. Do your research and be diligent on it. And if you need help, that's kind of what we're here for at EECO to be able to help you select the right types of devices to help protect your circuit and your facility. 

08:35 Chris: 

Absolutely great point. We are here to help, EECO Asks Why we're digging into these topics to help our listeners raise their education in some of these topics, as well as just being able to hear some of the experts like yourself, Jonathan, speak on it. So thank you so much for your time for your knowledge today, for everything that you share with our listeners. 

08:53 Jonathan: 

Yeah, absolutely. I thank you for having me. 

08:57 Chris: 

Thank you for listening to EECO Asks Why this show is supported ad free by Electrical Equipment Company. EECO is redefining the expectations of an electrical distributor by placing people and ideas before products, please subscribe and share with your colleagues and friends. Also leave comments, feedback, any new topics that you would like to hear. To learn more or to share your insights, visit That's E E C O A S K S W H