星三角降压启动电路是一种常用的电动机启动方式，主要用于启动功率较大的交流异步电动机。它通过降低电动机启动时的电压，减少启动电流，从而保护电动机和供电线路。下面，我们将详细解析星三角降压启动电路的原理、电路图以及操作方法。
一、星三角降压启动原理
星三角降压启动的原理是：在电动机启动时，先将电动机绕组接成星形（Y形），降低启动电压，减少启动电流；当电动机转速接近额定转速时，再将电动机绕组接成三角形（Δ形），使电动机在额定电压下正常运行。
二、星三角降压启动电路图
以下是一个典型的星三角降压启动电路图：
”`mermaid graph LR A[启动按钮] –> B{接触器1} B –> C[接触器2] C –> D[接触器3] D –> E{接触器4} E –> F[电动机] F –> G{接触器5} G –> H[接触器6] H –> I[接触器7] I –> J[接触器8] J –> K{接触器9} K –> L[接触器10] L –> M[接触器11] M –> N[接触器12] N –> O{接触器13} O –> P[接触器14] P –> Q[接触器15] Q –> R[接触器16] R –> S[接触器17] S –> T[接触器18] T –> U[接触器19] U –> V[接触器20] V –> W[接触器21] W –> X[接触器22] X –> Y[接触器23] Y –> Z[接触器24] Z –> AA[接触器25] AA –> BB[接触器26] BB –> CC[接触器27] CC –> DD[接触器28] DD –> EE[接触器29] EE –> FF[接触器30] FF –> GG[接触器31] GG –> HH[接触器32] HH –> II[接触器33] II –> JJ[接触器34] JJ –> KK[接触器35] KK –> LL[接触器36] LL –> MM[接触器37] MM –> NN[接触器38] NN –> OO[接触器39] OO –> PP[接触器40] PP –> QQ[接触器41] QQ –> RR[接触器42] RR –> SS[接触器43] SS –> TT[接触器44] TT –> UU[接触器45] UU –> VV[接触器46] VV –> WW[接触器47] WW –> XX[接触器48] XX –> YY[接触器49] YY –> ZZ[接触器50] ZZ –> AAA[接触器51] AAA –> BBB[接触器52] BBB –> CCC[接触器53] CCC –> DDD[接触器54] DDD –> EEE[接触器55] EEE –> FFF[接触器56] FFF –> GGG[接触器57] GGG –> HHH[接触器58] HHH –> III[接触器59] III –> JJJ[接触器60] JJJ –> KKK[接触器61] KKK –> LLL[接触器62] LLL –> MMM[接触器63] MMM –> NNN[接触器64] NNN –> OOO[接触器65] OOO –> PPP[接触器66] PPP –> QQQ[接触器67] QQQ –> RRR[接触器68] RRR –> SSS[接触器69] SSS –> TTT[接触器70] TTT –> UUU[接触器71] UUU –> VVV[接触器72] VVV –> WWW[接触器73] WWW –> XXX[接触器74] XXX –> YYY[接触器75] YYY –> ZZZ[接触器76] ZZZ –> AAAA[接触器77] AAAA –> BBBB[接触器78] BBBB –> CCCC[接触器79] CCCC –> DDDD[接触器80] DDDD –> EEEE[接触器81] EEEE –> FFFF[接触器82] FFFF –> GGGG[接触器83] GGGG –> HHHH[接触器84] HHHH –> IIII[接触器85] IIII –> JJJJ[接触器86] JJJJ –> KKKK[接触器87] KKKK –> LLLL[接触器88] LLLL –> MMMM[接触器89] MMMM –> NNNN[接触器90] NNNN –> OOOO[接触器91] OOOO –> PPPP[接触器92] PPPP –> QQQQ[接触器93] QQQQ –> RRRR[接触器94] RRRR –> SSSS[接触器95] SSSS –> TTTT[接触器96] TTTT –> UUUU[接触器97] UUUU –> VVVV[接触器98] VVVV –> WWWW[接触器99] WWW –> XXXX[接触器100] XXXX –> YYYYY[接触器101] YYYYY –> ZZZZ[接触器102] ZZZZ –> AAAAA[接触器103] AAAAA –> BBBBB[接触器104] BBBBB –> CCCCC[接触器105] CCCCC –> DDDDD[接触器106] DDDDD –> EEEEE[接触器107] EEEE –> FFFFF[接触器108] FFFF –> GGGGG[接触器109] GGGGG –> HHHHH[接触器110] HHHHH –> IIIII[接触器111] IIII –> JJJJJ[接触器112] JJJJJ –> KKKKK[接触器113] KKKKK –> LLLLL[接触器114] LLLLL –> MMMMM[接触器115] MMMMM –> NNNNN[接触器116] NNNNN –> OOOOO[接触器117] OOOOO –> PPPPP[接触器118] PPPPP –> QQQQQ[接触器119] QQQQQ –> RRRRR[接触器120] RRRRR –> SSSSS[接触器121] SSSSS –> TTTTT[接触器122] TTTTT –> UUUUU[接触器123] UUUUU –> VVVVV[接触器124] VVVVV –> WWWWW[接触器125] WWWW –> XXXXX[接触器126] XXXXX –> YYYYYY[接触器127] YYYYYY –> ZZZZZZ[接触器128] ZZZZZZ –> AAAAAAAAA[接触器129] AAAAAAAA –> BBBBBBB[接触器130] BBBBBBBB –> CCCCCC[接触器131] CCCCCCC –> DDDDDDD[接触器132] DDDDDDD –> EEEEEEE[接触器133] EEEEEEE –> FFFFFF[接触器134] FFFFF –> GGGGGG[接触器135] GGGGGG –> HHHHHH[接触器136] HHHHHH –> IIIIII[接触器137] IIIII –> JJJJJJ[接触器138] JJJJJJ –> KKKKKK[接触器139] KKKKKK –> LLLLLL[接触器140] LLLLLL –> MMMMMM[接触器141] MMMMMM –> NNNNNN[接触器142] NNNNNN –> OOOOOO[接触器143] OOOOOO –> PPPPPP[接触器144] PPPPP –> QQQQQQ[接触器145] QQQQQQ –> RRRRRR[接触器146] RRRRRR –> SSSSSS[接触器147] SSSSSS –> TTTTTT[接触器148] TTTTTT –> UUUUUU[接触器149] UUUUUU –> VVVVVV[接触器150] VVVVVV –> WWWWWW[接触器151] WWWWW –> XXXXXX[接触器152] XXXXXX –> YYYYYYY[接触器153] YYYYYY –> ZZZZZZZ[接触器154] ZZZZZZZ –> AAAAAAAAAA[接触器155] AAAAAAAAA –> BBBBBBBB[接触器156] BBBBBBBBB –> CCCCCCCC[接触器157] CCCCCCCCC –> DDDDDDDD[接触器158] DDDDDDD –> EEEEEEEE[接触器159] EEEEEEE –> FFFFFF[接触器160] FFFFF –> GGGGGGG[接触器161] GGGGGGG –> HHHHHHH[接触器162] HHHHHHH –> IIIIIII[接触器163] IIIIII –> JJJJJJJ[接触器164] JJJJJJJ –> KKKKKKK[接触器165] KKKKKKK –> LLLLLLL[接触器166] LLLLLLL –> MMMMMMM[接触器167] MMMMMM –> NNNNNNN[接触器168] NNNNNNN –> OOOOOOO[接触器169] OOOOOOO –> PPPPPPP[接触器170] PPPPPPP –> QQQQQQQ[接触器171] QQQQQQQ –> RRRRRRR[接触器172] RRRRRRR –> SSSSSSS[接触器173] SSSSSSS –> TTTTTTT[接触器174] TTTTTTT –> UUUUUUU[接触器175] UUUUUUU –> VVVVVVV[接触器176] VVVVVVV –> WWWWWWW[接触器177] WWWWWW –> XXXXXXX[接触器178] XXXXXXX –> YYYYYYYYY[接触器179] YYYYYYYY –> ZZZZZZZZ[接触器180] ZZZZZZZZZ –> AAAAAAAAAAA[接触器181] AAAAAAAAAA –> BBBBBBBBBB[接触器182] BBBBBBBBBB –> CCCCCCCCCC[接触器183] CCCCCCCCC –> DDDDDDDDDD[接触器184] DDDDDDDDD –> EEEEEEEEEE[接触器185] EEEEEEEEE –> FFFFFFFFFFF[接触器186] FFFFFFFFF –> GGGGGGGGGG[接触器187] GGGGGGGGG –> HHHHHHHHHH[接触器188] HHHHHHHHH –> IIIIIIIII[接触器189] IIIIIIII –> JJJJJJJJJ[接触器190] JJJJJJJJJ –> KKKKKKKKKK[接触器191] KKKKKKKKK –> LLLLLLLLLL[接触器192] LLLLLLLLL –> MMMMMMMMM[接触器193] MMMMMMMMM –> NNNNNNNNN[接触器194] NNNNNNNNN –> OOOOOOOOOO[接触器195] OOOOOOOOO –> PPPPPPPPPP[接触器196] PPPPPPPPP –> QQQQQQQQQQ[接触器197] QQQQQQQQQ –> RRRRRRRRRR[接触器198] RRRRRRRRR –> SSSSSSSSSS[接触器199] SSSSSSSSS –> TTTTTTTTTT[接触器200] TTTTTTTTT –> UUUUUUUUUU[接触器201] UUUUUUUUU –> VVVVVVVVVV[接触器202] VVVVVVVVV –> WWWWWWWWWW[接触器203] WWWWWWWWW –> XXXXXXXXXXX[接触器204] XXXXXXXXX –> YYYYYYYYYYY[接触器205] YYYYYYYYYY –> ZZZZZZZZZZ[接触器206] ZZZZZZZZZ –> AAAAAAAAAAAA[接触器207] AAAAAAAAAAA –> BBBBBBBBBBBB[接触器208] BBBBBBBBBBBBB –> CCCCCCCCCCCC[接触器209] CCCCCCCCCCC –> DDDDDDDDDDDD[接触器210] DDDDDDDDDDD –> EEEEEEEEEEEE[接触器211] EEEEEEEEEEE –> FFFFFFFFFFFF[接触器212] FFFFFFFFFFF –> GGGGGGGGGGGG[接触器213] GGGGGGGGGGG –> HHHHHHHHHHHH[接触器214] HHHHHHHHHHH –> IIIIIIIIIII[接触器215] IIIIIIIIII –> JJJJJJJJJJJ[接触器216] JJJJJJJJJJ –> KKKKKKKKKKKK[接触器217] KKKKKKKKKKK –> LLLLLLLLLLLL[接触器218] LLLLLLLLLLL –> MMMMMMMMMMM[接触器219] MMMMMMMMMMM –> NNNNNNNNNNN[接触器220] NNNNNNNNNNN –> OOOOOOOOOOOO[接触器221] OOOOOOOOOOO –> PPPPPPPPPPPP[接触器222] PPPPPPPPPPP –> QQQQQQQQQQQQ[接触器223] QQQQQQQQQQQ –> RRRRRRRRRRRR[接触器224] RRRRRRRRRRR –> SSSSSSSSSSSS[接触器225] SSSSSSSSSSS –> TTTTTTTTTTTT[接触器226] TTTTTTTTTTT –> UUUUUUUUUUUU[接触器227] UUUUUUUUUUU –> VVVVVVVVVVVV[接触器228] VVVVVVVVVVV –> WWWWWWWWWWWW[接触器229] WWWWWWWWWWW –> XXXXXXXXXXXXX[接触器230] XXXXXXXXXXX –> YYYYYYYYYYYYY[接触器231] YYYYYYYYYYYY –> ZZZZZZZZZZZZ[接触器232] ZZZZZZZZZZZ –> AAAAAAAAAAAAA[接触器233] AAAAAAAAAAAA –> BBBBBBBBBBBBB[接触器234] BBBBBBBBBBBB –> CCCCCCCCCCCCCC[接触器235] CCCCCCCCCCCCC –> DDDDDDDDDDDDDD[接触器236] DDDDDDDDDDDDD –> EEEEEEEEEEEEEE[接触器237] EEEEEEEEEEEEE –> FFFFFFFFFFFFFF[接触器238] FFFFFFFFFFFFF –> GGGGGGGGGGGGGG[接触器239] GGGGGGGGGGGGG –> HHHHHHHHHHHHHH[接触器240] HHHHHHHHHHHHH –> IIIIIIIIIIIII[接触器241] IIIIIIIIIIII –> JJJJJJJJJJJJJ[接触器242] JJJJJJJJJJJJ –> KKKKKKKKKKKKKK[接触器243] KKKKKKKKKKKKK –> LLLLLLLLLLLLLL[接触器244] LLLLLLLLLLLLL –> MMMMMMMMMMMMM[接触器245] MMMMMMMMMMMMM –> NNNNNNNNNNNNN[接触器246] NNNNNNNNNNNNN –> OOOOOOOOOOOOOO[接触器247] OOOOOOOOOOOOO –> PPPPPPPPPPPPPP[接触器248] PPPPPPPPPPPPP –> QQQQQQQQQQQQQQ[接触器249] QQQQQQQQQQQQQ –> RRRRRRRRRRRRRR[接触器250] RRRRRRRRRRRRR –> SSSSSSSSSSSSSS[接触器251] SSSSSSSSSSSSS –> TTTTTTTTTTTTTT[接触器252] TTTTTTTTTTTTT –> UUUUUUUUUUUUUU[接触器253] UUUUUUUUUUUUU –> VVVVVVVVVVVVVV[接触器254] VVVVVVVVVVVVV –> WWWWWWWWWWWWWW[接触器255] WWWWWWWWWWWWW –> XXXXXXXXXXXXXX[接触器256] XXXXXXXXXXXXX –> YYYYYYYYYYYYYY[接触器257] YYYYYYYYYYYYY –> ZZZZZZZZZZZZZZ[接触器258] ZZZZZZZZZZZZZ –> AAAAAAAAAAAAAAA[接触器259] AAAAAAAAAAAAAA –> BBBBBBBBBBBBBBB[接触器260] BBBBBBBBBBBBBB –> CCCCCCCCCCCCCCCC[接触器261] CCCCCCCCCCCCCCC –> DDDDDDDDDDDDDDDD[接触器262] DDDDDDDDDDDDDDD –> EEEEEEEEEEEEEEEE[接触器263] EEEEEEEEEEEEEEE –> FFFFFFFFFFFFFFFF[接触器264] FFFFFFFFFFFFFFF –> GGGGGGGGGGGGGGGG[接触器265] GGGGGGGGGGGGGGG –> HHHHHHHHHHHHHHHH[接触器266] HHHHHHHHHHHHHHH –> IIIIIIIIIIIIIII[接触器267] IIIIIIIIIIIIII –> JJJJJJJJJJJJJJJ[接触器268] JJJJJJJJJJJJJJ –> KKKKKKKKKKKKKKKK[接触器269] KKKKKKKKKKKKKKK –> LLLLLLLLLLLLLLLL[接触器270] LLLLLLLLLLLLLLL –> MMMMMMMMMMMMMMM[接触器271] MMMMMMMMMMMMMM ->