Dear All

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 ; AOTG30LFTC(5 units ; T007720, T011800, T011425, T018491, T020367)
    AOTG24LATC(1 unit ; serial number is unknown)
    Problem contents ;
    Error 95 was appeared. Technical found the burnout of compressor wire.
    After changing compressor, error has been fixed.

    Photo 1
  • Analysis result.
    <Investigation of manufacture record at factory>
    No record as repair.(Appendix 1)

    <Investigation of returned sample parts>

    Returned sample parts Terminal condition connected to compressor side


    Tip of red wire(burned wire) Tip of red wire(burned wire)(side view)

    　　　　　　
    　　Terminal of black wire and white wire Tip of terminal's caulking(left is black wire, right is white wire)

    Table 1. Terminal dimension of returned sample


    * The dimension of black wire and white wire is as normal.
    * Ultimate tensile strength of black wire and white wire is 200N or more. as the result, the falling out is nothing.

    < Investigation of FGT’s stock (Wire(9707837032) 50pcs)>
    The dimension of terminal ; same as normal
    Ultimate tensile strength ; n=10, 200N, and no falling out.

    <Sampling check result about manufacture company(Thai Lustar) of wire>
    * They are using the terminal which is same as normal.
    * Ultimate tensile strength is same as normal.
    (before manufacture had started at FGT, FGT had already checked.)

    *FGL checked the manufactured process at Thai Lustar. They has manufacture instruction.
    So, they are working correctly now.(Checked at 12nd Sep 2014)
  • Speculation of this problem’s cause.
    <the cause of burning>
    FGL guess;
    It became poor connection by any cause of wire or terminal.
    As the result, resistance of current became to increase.
    After that, wire burned by operating long time.

    As to sample parts, there was not the terminal that burnout has occurred.
    Therefore, FGL could not conclude this problem’s cause.
    However, FGL can think the cause like below;
    1. Terminal did not been inserted all the way.
    2. Terminal insertion method was messy.
    3. Terminal's caulking was poor.
  • Measure
    Made the assembly instruction.(Appendix 3)
    Carried out the training for factory worker by using assembly instruction.
  • Measure to product
    Already installed product; ; Measures by each location.
    Stock product; no measures. FGL think this problem will not happen often.
    Manufacture product ; Already measured.