I'm here, saying, to share some experience about the UL factory inspection:
1. Before the introduction: I wanna show some vocabularies about the factory inspection:
UL:Underwriters Laboratories
FUS: Follow Up service
FUS procedure: Follow-up service procedure, which we normally call it the UL certificate, but actually, the first page of this procedure is the real UL certificate.
Field representative: UL factory auditor
Manufacturer representative: the factory representative who's the interface with the UL factory auditor
Type L: one type of the UL products, normally needs to buy labels directly from the UL , but not all
Type R:another type of the UL products

2. UL inspection frequency:
For type L: basically, it depends on the output of the factory, that means it depends on the quantity of the UL label which the manufacturer used.
For Type R: normally, four times a year, but for some special products, not four times, but at least one time per year is needed

3. Construction of the FUS procedure:
Most of the Fus procedures are composed as below:
1)Authorization page: that's the first page of the Fus procedure, which generally shows your factory has the right to use the UL mark on your products.
2)index page: which show the general information of the products which are authorized by UL that the UL mark can be applied.
2)Sec.Gen.: general description of your products, cause normally, there are many specified sections in your FUS procedure, so the Sec.Gen show some common information of those different sections.
3)Sec.X: X represents the detailed section of your FUS procedure, which show the detailed descrition of the products covered by this section, most of the critical components are described in this section
4)Fig. and Ill: figures and illustrations which can show some visual information of your products
5)Test reports: which can show the test items and test methods when your factory applies for the UL approval.

4. Audit areas:
Normally, UL field representive will check five areas:
1)production line: to see the specified products and whether there are products with the UL mark on the production line.At this time, the auditor will check the comformance of the components and the online tests, even including the calibration information of the equipments on the production line.
2)warehouse for the components: when some components can not be verified on the production line, the auditor will check the warehouse to reconfirm the comformance of the components, as well the auditor will check some wire&cable's label which also a very important check item.
3)warehouse for the final products: to check whether there are some products with the UL mark which are not authorized by UL
4)testing area: to verify some test  items which required by UL, including the equipments' calibration information
5) shipping area: to check if  your factory are shipping non-authorized products.

5. Documents for UL auditor use:
For type L products, the UL auditor will use the related product standards and your FUS procedure, for example, AWM wire, the UL auditor will use below documents:
1)UL758, UL1581 standards
2)FUS procedure: including the FUII, style page, facing page
For type R products, normally, the auditor only use the FUS procedure, cause they don't have enough time to know each product standards.

6. Why VN was issued:
Most of those cases are as follows:
1) nonconformance of critical components, including the raw material, model No. dimensions and etc
2) noncomformance of the test : including the wrong methods and unqualified calibration
3) noncomformance of the test results:
4) non-authorization use of the UL mark: apply the UL mark on the products which are not authorized by UL
5) nonconformance of the COC documents: can not provide the right traceability documents during the inspection
6) other special cases: such as the refuse of the inspection and etc...

7. How to resolve the VN:
Normally, there are three ways to solve the VN, see below:
1) Rework under the witness: if VN found, and the VN can be solved in the field, then rework these VN items under the auditor's witness, then ok
2) Marking remove: if VN found, and these VN items are not so easy to be resloved in a short time, and you still want to ship these products, then select to remove the UL marking , then ok
3) Hold shipment: similar with the item 2), and you are not so urgent to ship out the products, or these VN items needs to be evaluated by the UL CAS department, then select to hold shipment until further confirmation was finished. but remember, don't ship out these products without the UL's approval.

8. Other recommendation:
1) Don't ship out the products with the UL mark before the IPI(first inspection) was finished
2) Don't show you are so experienced before the UL auditor, even you are a real experienced guy
3) If possible, prepare some gifts, or cash for urgent cases
4) Show respects to the UL auditor, even they are rude but not break your bottom line...


[ 此贴被Andy.Yang在2010-04-22 16:17重新编辑 ]

Thanks for sharing~~`  

would you like to give an example to explain it clearly?thank you in advance.

Which kind of example? do you mean the FUS procedure? If it is, I think it's difficult, cause the FUS procedure is some kinds of secret documents which belong to the manufacturer. If I show the specified FUS procedure, I will be appealed and trapped...
But if you mean the item 7, I can show some specified example:
1. Rework, for example:
Your FUS procedure requires that the factory ID must be shown on the marking, but actually there is no factory ID information on the marking, then the UL auditor will issue a VN about this issue. At this time, you can ask to rework this VN item and print an additional "ID" label, then attach this label to the products. I think this VN can be closed in field by the UL auditor;
2. Remove the UL mark, for example:
One kind of your products with the model No. "A" use the UL mark, but actually, this type of products is not covered and authorized by UL, then you can select to remove the UL mark under the witness of the UL auditor, then you can ship them out without further evaluation.
3.Hold shipment, for example:
The UL auditor issue a VN,but you can not accept this VN item and you wanna get further confirmation from the UL CAS departments, then you can select to hold this kind of products and wait the feedback from UL. Remember one thing, that the UL auditor has no right to destroy the products with VN, they also need to wait the CAS's feedback for the VN..

佩服。。。
你对UL FUS真的好了解，学习了

Quote:

引用第4楼jerryxiao于2010-06-08 21:18发表的  :
佩服。。。
你对UL FUS真的好了解，学习了

Thanks!

But not so many people focus on it, cause the guys always think such kind of inspections is just for fake...