基于plc雙電源開關(guān)設(shè)計(jì)外文翻譯-plc設(shè)計(jì)(完整版)
【正文】 the threephase openphase detection signal circuit, the threephase openphase detection signal circuit directly from the main circuit of threephase power supply, namely the intermediate relay KA1KA3 and KA4KA6, respectively connected to power supply main loop U1 and U2 A, B and C single phase circuit, KA1KA3 and KA4KA6 normally open contacts respectively as PLC input signal, namely as the preparation of PLC U1 and U2 threephase openphase detection logic control program input conditions. With short phase protection double load dual power automatic switching control, not only has the openphase protection, but also has a short circuit and overload protection, undervoltage protection function。 similarly, internal intermediate relay R2 as the threephase power supply of U2 threephase openphase detection, it’s on conditions for the normally open input X3, X4 and X5 and logic. In automatic switching control process, PLC ladder diagram procedure of auxiliary relay R1 and R2 respectively controlled AC contactor KM1 ( Y0 ) and KM2 ( Y1 ) coil and electric state, directly reflects two threephase power supply U1 and U2 respectively the total phase condition, namely, either U1 or U2 threephase power supply phase, KM1 ( Y0 ) or KM2 ( Y1 ) will immediately loses electricity, the normally closed contact of the alternating current contactor closed KM3 ( Y2 ) control coil gets electricity to attract, through the KM3 main contacts closed conduction contact loop, will be connected to the fault circuit load W1 or W2 automatically switches to a normal power supply U2 or U1 to power supply, so as to realize openphase protection automatic switching. In automatic switching control process, auxiliary relay R1 and R2 main function is: when troubleshooting, threephase power U1 or U2 recover the normal power supply, R1 (or R2) have electricity, the normally closed contact action, R3 reset, cut KM3 (Y2), then KM1 (Y0) or KM1 (Y1) plex have electricity, thereby automatically reverse switching back to the power supply to load W1 U1, U2 W
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鄂ICP備17016276號-1