As problem of title, I have received the problem report from quality assurance department.

I would like to inform about problem report detail.

  • Problem detail
    Product : AOTG18LVCC
    Quantity: 145 units
    Problem contents :
    As to this product, fuse warranty has occurred many times. each product had been send from factory by same lot.
    So, FGNZ checked stock product which had been send by same lot. Then, they found wiring mistake by factory.
  • Analysis result.
    1)Heat run check record at Factory
    There was no problem. but, heat run check cannot find this mistake.
    Because, when heat run check is carrying out, the current value is approximately 3.7A.
    Therefore, the possibility that fuse(F100) is broken in heat run check is nothing.
    And more, if compressor frequency is low, the fuse(F100) is not broken even if there is wiring mistake like this time.

    2)Patrol inspection at factory
    Factory worker had checked cable colour only. (they had not checked cable thickness.

    3)Sampling inspection at factory
    Visual inspection method is same as Patrol inspection. Operation inspection had carried out, but, could not find, because run time was short and current value was also low(2.1A).

    4)Manufacture record
    Date ; 19th July 2014
    Factory line; D line
    Quantity ; 145 units

    5)Manufactured record of similar product at same time.
    Below is manufactured record which was manufactured at the same time.
    We checked, but, wiring mistake is nothing at below product lot.
Product
 Line code
 Quantity
 Manufactured date
 Serial number
AOTG22LVCC
 B
 35
 2014.7.25
 E004546 to E004580
AOTG24LFCC
 B
 55
 2014.7.25
 E025389 to E025443
  • Speculation of this result’s cause.
    Cause of generation ; factory worker’s mistake
    Cause of outflow ; This was circuit which cannot find by heat run check process at factory.
  • Measure
    Improve work instruction document ; Add to check process of wire thickness and presence or absence of sleeve.(Appendix 1)
    Improve check sheet of patrol inspection ; Add to check process of thickness of lead cable.(Appendix 2)
    Carried out the training by using improve document for factory reader and worker.(Appendix 3)
  • Measure to product
    Already installed product; ; measures by each location if problem is occur.
    Stock product; no measures.
    Manufacture product ; already measured