hi Chad Hitt here application engineer at mechatronic Solutions today we'll be talking about UL 508a standards for industrial control panels so some of the things we'll be covering are uh underwriter Laboratories uh we'll Define the industrial control panel talk about the difference between 508 and 508a and also the relationship between between the NEC uh andul uh whether or not it's required and some of the criteria that goes into uh panel bill so uh slight disclaimer here um this is uh really just an overview uh you're not going to become certified uh as a result of this presentation um but um we'll try to cover uh all the highlights so starting with underwriter Laboratories uh underwriter Laboratories got their roots in uh fire safety uh which quickly encompassed um electrical safety um because electrical wiring and installations were frequently uh an item that frequently cause fires uh so they are a global Safety Science company uh they establish uh safety standards for many Industries and many different products they started as a nonprofit organization um however in 2012 um they actually um underwriter Laboratories which is a nonprofit became the parent company of UL LLC which is a for-profit company um not sure the implications there uh business practice wise but I thought it was um kind of uh kind of unique kind of neat to note um so um UL Laboratories are one of OSHA's nationally recognized Testing Laboratories uh meaning they're improved to perform safety testing for OSHA and um the best known product safety and certification organization globally um early on they started a label service for products which became the UL Mark uh and that was like starting in uh early 1900s um so products that got this uh the products that passed the UL testing and regular inspection uh got to um label uh with this UL Mark uh and you're going to see that uh you see that on everything from extension cords the vacuum cleaners microwave ovens um computers um everybody's um pretty familiar with the symbolic UL Mark so um UL what is ul508a it is the standard for industrial control panels um specifically um for the construction and installation of industrial control panels it provides uh guidelines for panel Builders um some of those being the what components he used uh the the the wiring the um shortcircuit current rating uh markings and where they go um and it describes an industrial control panel or defines that industrial control panel as an assembly of two or more power circuit components control circuit components or a combination of those and so these components are usually the the switches terminal blocks contactors motor drives Transformers all of the devices that you're going to put into an industrial control panel that industrial control panel is intended for General industrial use um at an operating voltage of 1,000 volts or less and so it what uh General industrial use includes packaging equipment assembly equipment plastic injection molding um Power uh press uh press controls press operation um irrigation systems Fountain control um Refrigeration elevator crane water treatment um a lot of different uh industries that it um that it encompasses uh what it doesn't include is it doesn't include like motor control centers um switch gear here uh that sort of thing so just some of those more service related um service entry uh related items um in an electrical installation uh so um we have ul508 and then there is uh kind of an extension of that is ul508a so ul508 covers um individual equipment uh individual components and devices so the circuit Breakers the power supplies the controllers um all of that um that you see um all of these components that are going to go into an industrial control panel where 508a um covers the uh the control panel the assembly itself so uh the enclosed industrial control panel or open industrial control panel um so oh this uh the ul508 is uh specific to um components used in industrial control panels so you're not going to find those extension cords and coffee makers in in this uh um listed under ul508 um it's all going to be devices that go into that control panel and uh and in those control panels we have en closed industrial control panel and open industrial control panel the um a lot of shops are um certified to label both indust uh enclosed and open uh the open the enclosed industrial control panel is one like you see up here in the top right corner um it basically just means it has an enclosure around it uh where we could also put a label on a panel uh like the one in the bottom left and that would be this open industrial control panel um it's basically an uh a panel that's uh intended to go in an enclosure um like at the point of installation um so um so we can still put a UL label on that for a panel that is going to get kind of embedded into a machine let say uh so what does this Mark mean to us um specifically like when I see this Mark what's that telling me so um for the component side in ul508 uh it's U that product we know that that product has been tested and evaluated by UL uh meaning samples were submitted they were tested they were found to meet these recognized standards and now they can put that UL mark on um on the control panel side under ul508a uh we know that that control panel has now been built to the standards of ul508 um that that label has given us that evidence that the enclosure meets um those nationally recognized safety standards um it's telling us that we've utilized certified components uh those components that are covered under ul508 um ensuring that we've got quality tested uh devices in there um and those assemblies as a whole that control panel assembly is then subject to inspection by UL so any time these panels can be inspected um usually throughout or or at the end of their build phase um you'll have monthly inspections from uh from a UL inspector um this also signifies that the panel Builder has met the requirements of ul508a um and they've uh which could be like circuit protection um uh wire sizing you know space requirements are adhered to uh all of that and each one of these shops needs to have a um qualified U manufacturer technical representative on staff and so basically this is something new in the last few years that that UL is implemented to become a qualified MTR you need to complete a UL training course uh and pass an exam and then that qualification is good for three years um at the end of that three years you retest um and uh and have to pass that um that MTR examination again and that it's uh it's not a cakewalk it's uh it's a pretty extensive uh test and you need to know uh that you 58a uh standard uh from front to back pretty well so um how does UL relate to the NEC let's say the the National Electric Code um so NFPA 70 is that National Electric Code um we usually refer to it as the NEC and um the NEC is uh it it's the code accepted by most agencies uh in the United States um for the installation of electrical equipment um so that's going to be more um more akin to the service installations that electrical service that gets installed um so the UL standard um looks at the construction of the panel so that basically uh covers the the construction of the panel assembly uh where the NEC is going to look at the manner in which that panel is installed so um when when that panel goes uh into the plant uh and the service gets hooked up to it um so any article 409 um covers industrial control panels um that article um now references ul508a in a few places um they both describe the industrial control panel um with the same definition um and uh you know just article 409 is about two pages long where ul508 is about 200 pages long um now there's other aspects of the NEC that are covered in 508a but um but that's just a good for instance um and then on top of that we've got uh NFPA 79 and so NFPA 79 is going to be the electrical standard for industrial machinery and so that is going to kind of Encompass the the machine as a whole um not just the control panel um but uh so an easy way to think about the relationship between 508a and NEC is that um kind of like the relationship between uh the components of ul508 and how they're used in that assembly uh that panel assembly 508a is uh is going to be a component of that NEC installation so good question do is it required do I need to have UL a way day on my panel it's actually not mandatory by law or regulation so uh technically no um it's you don't need it however by the end of the slide you're going to see um it's uh the qu the answer to that question is uh more of a resounding yes so even though uh it's not mandatory or required um compliance with 508a is required by electrical inspectors uh insurance providers equipment purchasers um just the that overall compliance and so a good for instance there is uh uh Minnesota statute you can see I have posted here um or exerpts from it um and that is uh 3801 3620 subdivision three um and it it really in a nutshell says if uh the panel is not listed it falls on the purchaser or the electrician overseeing the installation to provide proof to the electrical inspector that the equipment complies with applicable electrical standards uh when I say it falls on the purchaser electrician that's usually always pushed back on the OEM or the manufacturer of the panel um so uh really it's going to fall on that um panel supplier um but you can see that um to provide um all of the all of this proof um it's that would be a huge undertaking for um for any one of the individuals um and they typically don't want to take on you know such as the electrical the master electrician let's say he's not going to want to take on that responsibility um and so for that reason most purchasers and electricians are going to just require um ul508a so it makes it easier for for everyone really um so some of the criteria that goes into um listing a panel um is uh you know first and foremost you need to use uh listed or recognized components and we'll cover recognized components in a middle uh in a in a minute on the next slide um but those components are going to be your your wire your terminals controllers um all all those individual devices uh we need to make sure that we have properly sized circuit protection uh we need to know the difference between branch circuit protection and supplementary protection uh properly sized motor overloads uh properly sized wiring um and not just properly sized but properly marked we need to show the label on the spool that the wire came from um so like when we have a uh uh an inspection uh UL inspector in for uh for an inspection and uh and and part of that is because wire is the most counterfeit product uh uh in with the UL Mark so um wire is one of the number one items that gets counterfeited uh for UL so they need to see that spool that the that the wire came off of um many of these components will have space requirements um and these are usually devices that are heat producing so you'll have um a space requirement um you know this is exerpt out of a manual um for a power supply and you just need that air convection um to in from sometimes you can stack components together side by side sometimes you'll have a uh a horizontal uh space requirement also um and so um we need to make sure that you know you abide by all those SP requirements um markings and labels um there's required markings and there's even required placement for some of those markings um and uh you know these include name plates warning labels um fuse and overload call outs um schematics uh you know kind of all of that and Compass all that documentation uh and then you also have to have a uh short circuit current rating uh established for that um for that assembly um which we'll get into uh in a minute also first though we have listed versus recognized um a listed component is going to bear that UL um UL logo with the circle around it um and these are the devices that have actually been um tested um and confirmed certified for uh for use in uh industrial control panel um and you know many other electrical installations um but we can also use recognized components so products uh can be well recognized which means um they were um tested or found to be safe in in particular instances um and so those are going to be reviewed and AC accepted by the final application so uh if we as an oem or a panel Builder are utilizing a recognized component component in a control panel we might uh we need to ensure that the application meets the requirements of of that um either described in our uh UL procedure or we find them in uh supplement saay so that's a supplement to the um to the ul508a standard uh so uh good for instance here um the circuit breaker shown and the power supply are both uh UL listed um where the terminal blocks um that you find in many many uh control panels are recognized and the recognized symbol is that backwards Ur for some reason lastly here we have uh shortcircuit current readings um and and available fault current so starting with available fault current uh any any incoming electrical service to a building has an available full current is the maximum current available uh if you had a short circuit such as short to ground the NEC requires that that available fault current uh is marked on the surface equipment the panel board switchboard switch gear uh so in other words the the breaker panels uh will have that available F current listed so then the components uh the individual components will have uh a short circuit current grading the secr uh and that's going to be listed by the manufacturer um so uh sometimes it's listed right on the component sometimes you have to look it up in a data sheet uh but there will be an secr assigned to to any of those components that go in uh in that panel so the sccr for um for that panel will then need to be calculated based on those component ratings and your circuit design or circuit layout so uh the um and then that overall secr um needs to be listed on the name plate so much like um the NEC requires it to be listed on the on the breaker panels um we need to list that on the name plate of the uh of the control panel so then that uh the E the secr of that equipment has to be greater than the available fault current of the service so the um if we have an available fault current uh these fault currents are typically uh expressed in thousands of amps are in Ka so um you can see from this exerpt uh out of an eaten catalog that uh we see them in 10ka 18ka 35 all the way up to 200ka um the uh the minimum the lowest rating is 5ka um so uh in this case you can see miniature fuses typically have a rating of 10ka however um if you if you follow that out to the right uh we can get those in up to 18 35 65 all the way up to 200ka so if we have a panel That's rated for 10ka um and we have an uh an available fault current uh at the service um or the service to that panel of 18 AA that panel is never going to pass inspection it's not going to be able to install uh in that application so we'd have to go back and change some of those components in the panel to uh to be able to get that secr rating up to you know over 18 so um um 20 25 35 100 um and uh and en able to uh once we get that panel to a you know say 25ka now it we can install that in in an 18ka uh Service uh or a service with an 18ka uh available fault current so that is sccr in a nutshell and uh that uh wraps up our ul508a overview um again these are just some of the highlights of the ul508a standard um that standard is over 200 pages long um include UPL that supplement essay in there for another 57 Pages um and you can see there's a there's a lot to learn and know about it um but I hope uh hope this was helpful thank you