失败模式及效应分析.ppt

Furnace Test Background Every Residential Gas Furnace is tested ( +350k / year) Each test has different pass / fail criteria (based on model) (aka Test Parameters These are controllable by Test Engineer - not operator. The cables, door clip, etc that are used to connect the unit to the tester were listed as (S) SOP as they are not “knob variables that can be adjusted to have an effect on the outcome of a test. Obviously, if installed incorrectly or in wrong location the effect will be test failure. Some cables are Poka Yoke and some are not. The ampclamp can snap around any wire in any location. If placed too near a motor it’s accuracy is disturbed by electromagnetic fields. Prior to each test the unit’s Model & Serial Number is scanned. This initiates a check of the Electronic Total Quality Check (ETQC) system to verify that key parts installed in this unit have been barcode scanned to show they belong in this model. If all is well the Model number scanned selects the correct parameter file and the test may be started by the Operator. If not, the test operator will be shown a screen as to which part needs to be verified that it belongs and the operator can scan the part and Model number barcode to verify. The op may have to install the correct part before scanning. Once the test is started the operator follows the test display and is prompted when he needs to connect the ground wire and press a button to have the test continue. He has 30 seconds to do this. It usually takes less then 7 seconds . If the operator has left his test station (inattentive, getting literature or “spare” parts, whatever) and doesn’t continue the test... It will fail. Each furnace as a Door switch that will prevent the unit from operating if the doors are left off by a service person or homeowner (replacing a filter, etc.) The furnaces are tested without the doors in place so it is necessary to put a clip on the door switch to hold it closed to simulate a door is in place. If t