630KVA的变压器用1250A的开关?用YJV-4X(3X300)+2X300合适吗？是不是大呀？浪费不？
推荐回答（3个）
楼主，开关的选型和电缆的选型基本合适，630KVA变压器低压侧的额定电流就得957A，电缆超过200mm2以上，1mm2带1安培电流也基本合适，四根300mm2=1200mm2，选的挺好
截 面 0.6/1KV(A) θn=90℃ 6/6KV~8.7/10KV(A) θn=90℃ 26/35KV(A) θn=80℃
（mm2） 4 芯 单芯θn=30℃ 3 芯 单芯θn=30℃ 3芯 单芯θn=30℃
20℃ 25℃ 30℃ 20℃ 25℃ 30℃ 25℃
4 42 40 38
6 47 45 43
10 62 60 58
16 83 80 77
25 104 100 96 109 105 101
35 125 120 115 130 125 120
铝 50 146 140 134 151 145 139 137
70 182 175 168 187 180 173 215 205 172
95 218 210 202 224 215 206 255 235 206
120 244 235 226 255 245 235 280 265 224
芯 150 276 265 254 286 275 264 320 305 243
185 317 305 293 322 310 298 350 335
240 369 355 341 374 360 346 400 390
300 416 400 384 440 430
400 505 515
500 555 575
630 610 640
4 52 50 48
6 62 60 58
10 83 80 77
16 104 100 96
25 135 130 125 140 135 130
铜 35 161 155 149 166 160 154
50 192 185 178 198 190 182
70 234 225 216 239 230 221 270 260 177
95 281 270 259 286 275 264 320 300 221
120 317 305 293 322 310 298 355 340 267
芯 150 359 345 331 364 350 336 390 385 288
185 406 390 374 411 395 379 430 430 313
240 473 455 437 473 455 437 490 490
300 536 515 494 535 550
400 595 570
500 655 630
630 710 765
注：1、同表9—27注。
2、若考虑土壤水分迁移时，表中载流量应乘以校正系数0.78。
自己看看载流量就知道了
开关选择是对的！电缆的安装方式你没有说，长度也没有说！我们怎么给意见啊！我孤陋寡闻YJV是铜的还是铝的啊！
我觉得电缆选的有点大！大的多！
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