A UL508A panel shop question

[lefty]

A UL 508A panel shop is contemplating having a non UL shop build the panels for them at a non UL shop location. Upon completion of the panels the non UL shop will ship the panels to the UL shop for inspection and applying the UL sticker if it passes inspection. The UL shop will furnish all materials.

I was thinking that part of being a UL listed shop was that the work had to be done in a specific location, for a quality control atmosphere.

The only way this would work is for the UL listed shop to have qualified inspectors that could do field labeling, I believe. Because they would be inspecting basically the work of someone else even in their own shop.

Basically I'm asking if the Listed shop can do this sort of thing?

 

[Jraef]

Could? Yes. Good idea? Not without qualification as described below.

Part of being a UL508A shop is having UL evaluate your assembly procedures (wiring methodes, materials used, layout, engineering etc.), processes (recordkeeping, planning etc.) and QA. As part of the ongoing listing, they conduct random inspections and check all aspects of your production. If you are doing some of the production off-site, and you are not including that off-site location under your UL listing, then you are committing fraud.

If you do include the other site, you will have to pay UL to inspect it as well, and the workers there will need to be trained on what to do. It does happen, especially in areas where the labor rates are significantly cheaper than where the main shop is. For example this happens here in California sometimes because our labor rates are (or were) higher than somewhere like Florida. I know of two shops that have a lot of their higher volume standardized panels pre-built in Florida and they just customize them here. But in their case, the Florida shops are UL508A listed as well.

UL aslo allows, under special circumstances, the extension of your listing to a different company even if they are not themselves UL508A listed on their own. It still means inspections, and the "parent" company pays for this as if the other shop were theirs. The only time I see that provision used is when a component mfr wants to capture a specific large local market and does not want to open their own separate shop, so they "license" their UL508A to a panel shop that doesn't have one, as long as that shop ONLY uses their components and procedures and only for the products the parent company wants them to build.

 

[jimnan88]

I would say this would depend greatly on the complexity of the assembly and the components used. Part of the UL inspection process is inspecting the shop skills.
With a simple panel say a pump stop start control where all the components are UL LISTED not just recognized the assembly is pretty straight forward and the specification of these components is also straight forward. It is when you get into the non listed and recognized components that is where problems are going to start or on a panel that is not a simple layout and install with a simple circuit. This is where the problems will start.
The question I would ask myself is if the installation would require me to supervise that assembly myself or could I trust the installer to understand my wiring diagram and perform this unsupervised.
Often times there is a grave misunderstanding about fuses and circuit breakers and of course supplementary protection, also voltage specifications. Terminal strip fuse holders all look the same but may have very different voltage ratings. training and developing a shop that is aware to look at this take patience and time. I can only think that someone feels having the non ul shop build panles is going to save money. For VERY simple repetative work it may, then again if the inspector pulls a fuse holder off the DIN rail and it is a 57 Volt fuse holder instead of a 300 VAC fuse holder off the DIN rail in a 120 VAC circuit you are going to have problems. An allen bradley 1492 H5, looks just like a 1492 H4 and you cannot read the side easily if at all once it is installed.
I have seen UL inspectors pull part panels to check details like this.

 

[renosteinke]

Why is this question being asked in this forum?

You're asking for UL to put their label on your product - don't you think it is UL that you must ask? Only UL can decide what factors matter to them, and what constitutes a acceptable arrangement. It's quite possible that UL would want to institute separate inspections and tests for the 'foreign' assemblies that are being used.

It matters not whether the 'other' parts are UL recognized or not. When you got the shop listed, certain parts were described. Even if you were to do something as simple as change the brand of pushbuttons used from A-B to C-H, UL would want to be informed of the change.

If you're a UL shop, you have their card. Call your UL rep.