The electric sewing machine no-load energy-saving low-voltage circuit breakers by the QF, control switch Sl, S2 and light switch S4, foot switch S3, AC contactor and relay KT KM composition, shown in Figure 8-4.
EL for lighting lamps , M for the electric sewing machine motor .
Use, the first low-voltage circuit breakers connected to QF, and then connect S1 and S2, sewing workers to foot on the clutch pedal , so that the foot switch S3 disconnects , KM pull power , its normally open contact KMl connected M starter motor operation , lighting, EL lamp lit , the workers can start sewing work .
In the sewing operation for living space or when the foot sewing workers will leave the clutch pedal , S3 closed , the time relay KT pull power , delay start . When the intended delay time , KT delay disconnected normally closed contact is open, so that power the release of KM , M to stop running , EL off, soM No-load power consumption to avoid .
When the sewing workers continue to work, then ride a moving clutchPedal , so that S3 disconnect , KT power reset , KM power pull , M start running , they began sewing work .
M Stood in need of illumination , if the Secretary , the lights can be connected to manually switch S2, to EL light .
S1, S2 , and called all chosen contacts current SA more self-locking power switch ; S3 use protection -type move off button .
KM choose coil voltage 220V, current of lOA contact exchange contactor .
KT selected delay time range of 0.4 -1805 Secretary 220V AC relay when the Secretary .
QF use 380V, l0-2OA of the low-voltage circuit breakers .
EL using the original lamp .