需要系數(shù)法確定計算負(fù)荷

1、(1)用電設(shè)備組的計算負(fù)荷及計算電流:有功功率PjsK X PN ,kW（ 5-2-5）無功功率QjsPjstg,kvar （ 5-2-6）視在功率Sjsp2jsQ2s, kVA（5-2-7）Sjs計算電流Ijs J , A (5-2-8 )V3Ur(2)配電干線或車間變電所的計算負(fù)荷：有功功率PJsK p（KxPn）, kW（5-2-9）無功功率QjsK q（KxPztg ）, kvar（5-2-10）視在功率Sjs,pj2Q2s, kVA（5-2-11）以上式中Pn 用電設(shè)備組的設(shè)備功率，kWKx 需要系數(shù)；見表 5-2-1、表5-2-2及表5-2-3 ；tg 用電設(shè)備功率因數(shù)角的正切值，

2、見表5-2-1、表5-2-3、表5-2-4及表5-2-5 ；K P、K q 有功功率、無功功率同時系數(shù)，分別取0.80.9和0.930.97 ；Ur用電設(shè)備額定電壓(線電壓)，kV表5-2-1用電設(shè)備的KX、cos及tg用電設(shè)備組名稱單獨傳動的金屬加工機床小批生產(chǎn)的金屬冷加工機床0.120.160.501.73大批生產(chǎn)的金屬冷加工機床0.170.200.501.73小批生產(chǎn)的金屬熱加工機床0.200.250.550.601.511.33大批生產(chǎn)的金屬熱加工機床0.250.280.651.17鍛錘、壓床、剪床及其他鍛工機械00.250.601.33木工機械0.200.300.500.601.73

3、1.33液壓機0.300.601.33生產(chǎn)用通風(fēng)機0.750.850.800.850.750.62衛(wèi)生用通風(fēng)機0.650.700.800.75泵、活塞型壓縮機、電動發(fā)電機組0.750.850.800.75球磨機、破碎機、篩選機、攪攔機等0.750.850.800.850.750.62電阻爐（帶調(diào)壓器或變壓器）非自動裝料0.600.700.950.980.330.20自動裝料0.700.800.950.980.330.20干燥箱、加熱器等0.400.601.000工頻感應(yīng)電爐（不帶無功補償裝置）0.800.352.68高頻感應(yīng)電爐（不帶無功補償裝置）0.800.601.33焊接和加熱用咼頻加熱設(shè)

4、備0.500.650.701.02熔煉用咼頻加熱設(shè)備0.800.850.800.850.750.62表面淬火電爐（帶無功補償裝置）電動發(fā)電機0.650.701.02真空管振蕩器0.800.850.62中頻電爐（中頻機組）0.650.750.800.75氫氣爐（帶調(diào)壓器或變壓器）0.400.500.850.900.620.48真空爐（帶調(diào)壓器或變壓器）0.550.650.850.900.620.48電弧煉鋼爐變壓器0.900.850.62電弧煉鋼爐的輔助設(shè)備0.150.501.73點焊機、縫焊機0.35, 0.20 0.601.33對焊機0.350.701.02自動弧焊變壓器0.500.501.

5、73單頭手動弧焊變壓器0.350.352.68多頭手動弧焊變壓器0.400.352.68單頭直流弧焊機0.350.601.33多頭直流弧焊機0.700.701.02金屬、機修、裝配車間、鍋爐房用起0.100.150.51.73重機（& =25%鑄造車間起重機（ =25%0.150.300.51.73聯(lián)鎖的連續(xù)運輸機械0.650.750.88非聯(lián)鎖的連續(xù)運輸機械0.500.600.750.88一般工業(yè)用硅整流裝置0.500.701.02電鍍用硅整流裝置0.500.750.88電解用硅整流裝置0.700.800.75紅外線干燥設(shè)備0.850.901.000.00電火花加裝置0.500.601.33

6、超聲波裝置0.700.701.02X光設(shè)備0.300.551.52電子計算機主機0.600.700.800.75電子計算機外部設(shè)備0.400.500.501.73試驗設(shè)備（電熱為主）0.200.400.800.75試驗設(shè)備（儀表為主）0.150.200.701.02磁粉探傷機0.200.402.29鐵屑加工機械0.400.750.88排氣臺0.500.600.900.48老煉臺0.600.700.701.02陶瓷隧道窯0.800.900.950.33拉單晶爐0.700.750.900.48賦能腐蝕設(shè)備0.600.930.40真空浸漬設(shè)備0.700.950.33點焊機的需要系數(shù)0.2僅用于電子行

7、業(yè)表5-2-2照明用電設(shè)備需要系數(shù)建筑類別&建筑類別生產(chǎn)廠房（有天然采光）0.800.90宿舍區(qū)0.600.80生產(chǎn)廠房（無天然米0.901.00醫(yī)院0.50光）辦公樓0.700.80食堂0.900.95設(shè)計室0.900.95商店0.90科研樓0.800.90學(xué)校0.600.70倉庫0.500.70展覽館0.700.80鍋爐房0.90旅館0.600.70表5-2-3旅游旅館用電設(shè)備的Kx、cos及tg用電設(shè)備組名稱Kx用電設(shè)備組名稱Kx昭八、明客房0.35 0.450.950.33電梯0.180.220.501.73其他場所0.50 0.70洗衣機0.30 0.350.701.02冷水機組、泵

8、0.65 0.750.800.75廚房設(shè)備0.35 0.450.750.88通風(fēng)機0.60 0.700.800.75窗式空0.35 0.450.800.75調(diào)器表5-2-4 照明用電設(shè)備的cos及tg光源類別光源類別白熾燈、鹵1.000.00高壓鈉燈0.451.98鎢燈熒光燈（無0.551.52金屬鹵化物0.400.612.291.29補償）燈熒光燈（有0.900.49鏑燈0.521.60補償）高壓汞燈0.450.651.981.16氙燈0.900.48表 5-2-5 cos 與 tg 、sin1.0000.0000.0000.8700.5670.4930.6501.1690.7600.990

9、0.1420.1410.8600.5930.5100.6001.3330.8000.9800.2030.1990.8500.6200.5270.5501.5180.8350.9700.2510.2430.8400.6460.5430.5001.7320.8660.9600.2920.2800.8300.6720.5580.4501.9850.8930.9500.3290.3120.8200.6980.5720.4002.2910.9160.9400.3630.3410.8100.7240.5860.3502.6760.9370.9300.3950.3670.8000.7500.6000.3003.1800.9540.9200.4260.3920.7800.8020.6260.2503.8730.9680.9100.4560.4150.7500.8820.6610.2004.8990.9800.9000.4840.4360.7200.9640.6940.1506.5910.9890.8900.5120.4560.7001.0200.7140.1009.9500.9950.8800.5400.