A common electrical failure cause analysis X6132 milling machine

Fault phenomenon: the spindle motor M1 cannot start, analysis of reasons. Cause analysis: if switch SA2 in the off position. Is the cause of the problem is: (1) SQ6, SB1, SB2, SB5, SB6, KT delay contact as a poor contact or circuit breakers. (2) thermal relay FR1, FR2 action not reset after causing them to the normally closed contact of conduction. (3) contactor KM1 coil circuit. Fault phenomenon: the spindle motor or impulse time is too long, can't change impulse analysis reasons. Cause analysis: (1) SQ6 - 1 contact or touch of time relay KT point contact undesirable. (2) the impulse for too long the reason was that the time relay KT delay too long. Fault phenomenon: the workbench in all directions can feed cause analysis: (1) the auxiliary contact KM1 KM1 ( 6 - 9) Poor contact. (2) thermal relay FR3 not reset after action. Fault phenomenon: can't feed speed impulse cause analysis: if the table can normal feed in all directions, then the failure possibility is SQ5 - 1 normally open contacts. Fault phenomenon: the workbench to left and right before and not after the movement, the campaign cause analysis: due to the workbench can control movement, so SQ1, for SQ2 no fault; Because the workbench to forward and downward movement, so SQ7, SQ8, SQ3 without fault, fault SQ4 is the likely cause of the stroke switch so SQ4 - normally open contacts A poor contact. Fault phenomenon: the workbench to the left, right, and before and after movement rather than upper and lower movement cause analysis: due to the workbench can control movement, so SQ1, for SQ2 no fault; Because the table can exercise before and after, so of SQ3 and SQ4, SQ7, YC4 have no fault, so the fault may touch SQ8 normally open contacts is the cause of bad or bad YC5 coil. Fault phenomenon: the workbench can't fast moving cause analysis: if the workbench can normal feed, then fault possibility is SB3 or SB4, KM4 normally open contacts, YC3 coil is bad.