how and how much to become a UL panel shop?

[ndzied1]

I thought I knew what a UL panel shop was but Norm's descriptions makes me think I don't.

I have been operating under the impression that there were two different UL paths for 508A. The first is a type certification. You submit a design, build a panel and have it inspected. If that inspection passes you can build and sticker as many of that panel as you like as long as you change absolutely nothing. If you change something the whole deal needs to be re-inspected and re-certified. This type of operation would be subject to periodic inspections to make sure the design is still unchanged and that the panels are being built to standard.

I'm pretty sure you can do this but we are always building different stuff so it would never make sense for us.

The other path requires inspection of every panel manufactured. In a funny twist the inspection is free.

I have never heard of this but I haven't heard of everything. This may be something offered if you just do a few panels per year. We do 100's.

It is the writing of the report if a variance is found that costs the money.

This is true no matter how you go

Also, each panel shop has a list of recognized components they are allowed to use along with a procedure that indicates how they are applied. Each procedure costs money. I think this is the data gathering thing that jraef was talking about. We have been politely asked by our UL panel shop to use specific components if possible so that we stay within their described procedures list.

We don't have any procedures attached to our UL file. That means we have to use only the components allowed by the standard. For instance to use a circuit breaker in a branch circuit it must be listed to UL489... If we wanted to use a breaker that wasn't listed to UL489 in a branch circuit we could pay UL to investigate and if they determined that it was ok, they would write a procedure that would get added to our file and we could use that breaker as described in the procedure in our listed panels. The standard is mature enough that for most things you can find off the shelf components for almost everything you'd ever want to put in a panel. There's even a "get out of jail free card" for a single component that doesn't meet the spec by putting it in a ground fault circuit (going from memory here, we have never used this method. There's probably a little more to it and some other limitations but it does try to give you an out).

For an organization like UL the seems king of "fox-in-charge-of-the-henhouse"-ish but I may be wrong.

Everybody is different but I'm pretty much a stickler about our listed panels. Our largest customer has us list every panel for them because they go all over the country. I would not risk this business by putting a sticker on something I wasn't sure met the standard. I have turned down work for listed panels because I knew the components the customer wanted us to use do not meet the standard even though another shop was going to list their panels with these parts. The number on the sticker can always be traced back to us and I won't risk getting our file pulled and losing our biggest customer.

 

[kamenges]

Originally posted by ndzied1:

There's even a "get out of jail free card" for a single component that doesn't meet the spec by putting it in a ground fault circuit (going from memory here, we have never used this method. There's probably a little more to it and some other limitations but it does try to give you an out).

There is more to it and, more importantly, UL is becoming really restrictive on this little design trick. This is a section where the rules (or more correctly the interpretation and enforcement of the rules) are changing very quickly. It is a methodology that is of absolutely no benefit to UL and they treat is as such.

Originally posted by ndzied1:

Everybody is different but I'm pretty much a stickler about our listed panels.

I have very little doubt that is true. However, that doesn't change the essential nature of the relationship. In a very fundamental sense you should never have any variances on any panels, since you are building them AND inspecting them. Very few of us do the wrong thing on purpose. That doesn't mean the wrong thing isn't done from time to time.

Keith

 

[jraef]

So there are two levels of products you can use as a UL 508A shop.

1) You can use ANY product that is UL Listed under one of the dozens of UL file numbers in the 508A documents. LISTED products can be used without additional procedures or paperwork.

2) You can also use UL Recognized Components , differentiated by the backwards UR symbol;

"Recognized" means they can ONLY be used in a specific manner WITH other specific components. To use those, you must "add them to your procedure", meaning you must write up a thorough description of exactly how you will use them and with what, including all of the UL file numbers of the separate components. Here is a perfect case in point: plug-in ice cube relays. If I buy an Idec relay, it can ONLY be plugged into an Idec socket (most people are unaware of this by the way). The Idec relay is UL listed, but NONE of the sockets are, they are all UR, and in their UR files, they specifically list the relays or timers they can be used with. There is ZERO incentive for Idec to list their sockets for use with Tyco relays, and vice versa. So if you get a great deal over the internet on 8 pin sockets, thinking they are all functionally the same (and they are), you can get a rude awakening by your UL inspector if he notices that they are different brands. Most DIN rail terminal blocks are UR as well, because they have ONLY been evaluated when used with specific end barriers and clamps. This is why it is difficult for a panel shop to change brands on things like TBs, it means adding them to their procedure (although savvy suppliers will do most of the paperwork for you if there is enough potential volume).

So yes, you can get away with not having a "procedure" simply by never using anything other than UL LISTED components. But that means no plug-in relays, no DIN rail TBs, etc.

Getting a single panel UL listed and only building that ONE panel without ever changing it is not UL508A, that is just plain UL508, the procedure for getting a PRODUCT listed. By only building the same thing and never varying it, it can be considered a "product", not a "custom assembly". The danger there is that if a mfr. stops making one of your components, you may end up paying UL all over again.

 

[ndzied1]

2) You can also use UL Recognized Components , differentiated by the backwards UR symbol;

"Recognized" means they can ONLY be used in a specific manner WITH other specific components. To use those, you must "add them to your procedure", meaning you must write up a thorough description of exactly how you will use them and with what, including all of the UL file numbers of the separate components. Here is a perfect case in point: plug-in ice cube relays. If I buy an Idec relay, it can ONLY be plugged into an Idec socket (most people are unaware of this by the way). The Idec relay is UL listed, but NONE of the sockets are, they are all UR, and in their UR files, they specifically list the relays or timers they can be used with. There is ZERO incentive for Idec to list their sockets for use with Tyco relays, and vice versa. So if you get a great deal over the internet on 8 pin sockets, thinking they are all functionally the same (and they are), you can get a rude awakening by your UL inspector if he notices that they are different brands. Most DIN rail terminal blocks are UR as well, because they have ONLY been evaluated when used with specific end barriers and clamps. This is why it is difficult for a panel shop to change brands on things like TBs, it means adding them to their procedure (although savvy suppliers will do most of the paperwork for you if there is enough potential volume).

So yes, you can get away with not having a "procedure" simply by never using anything other than UL LISTED components. But that means no plug-in relays, no DIN rail TBs, etc.

Getting a single panel UL listed and only building that ONE panel without ever changing it is not UL508A, that is just plain UL508, the procedure for getting a PRODUCT listed. By only building the same thing and never varying it, it can be considered a "product", not a "custom assembly". The danger there is that if a mfr. stops making one of your components, you may end up paying UL all over again.

That is they way it was early on in the UL508A program. Indeed our original file book was 3 inches thick and 2 inches were terminal procedures.

However, the SA table is the key to when you need a procedure or not. If you look at the current version of the spec, the SA table says you can use UL1059 Recognized terminals if you follow sizings from section 28, spacing from section 10 and conditions of use from the Recognized Components information page. If you needed to have a procedure to use these, the SA table would simply say "Procedure Described Only" as it does in may other places.

This is what they taught us in the class at UL.

 

[ganutenator]

so much good info.
Thanks everyone.
Still digesting it all.