两极防护。
(4)按照《JGJ46-2005》规定制定施工组织设计，接地电阻R≤4Ω。 2、确定用电负荷
(1)、塔式起重机
Kx = 0.2, Cosφ = 0.6, tgφ = 1.33 Pjs = 0.2 ×70 = 14 kW
Qjs = Pjs × tgφ= 14× 1.33 = 18.62 kvar
(2)、插入式振动器
Kx = 0.3, Cosφ = 0.7, tgφ = 1.02 Pjs = 0.3 ×0.8 = 0.24 kW
Qjs = Pjs × tgφ= 0.24× 1.02 = 0.24 kvar
(3)、插入式振动器
Kx = 0.3, Cosφ = 0.7, tgφ = 1.02 Pjs = 0.3 ×1.1 = 0.33 kW
Qjs = Pjs × tgφ= 0.33× 1.02 = 0.34 kvar
(4)、平板式振动器
Kx = 0.3, Cosφ = 0.7, tgφ = 1.02 Pjs = 0.3 ×0.5 = 0.15 kW
Qjs = Pjs × tgφ= 0.15× 1.02 = 0.15 kvar
(5)、灰浆搅拌机
Kx = 0.5, Cosφ = 0.55, tgφ = 1.52 Pjs = 0.5 ×3 = 1.5 kW
Qjs = Pjs × tgφ= 1.5× 1.52 = 2.28 kvar
(6)、直流电焊机
Kx = 0.35, Cosφ = 0.6, tgφ = 1.33 Pjs = 0.35 ×6 = 2.1 kW
Qjs = Pjs × tgφ= 2.1× 1.33 = 2.79 kvar
(7)、木工圆锯
Kx = 0.3, Cosφ = 0.6, tgφ = 1.33 Pjs = 0.3 ×3 = 0.9 kW
Qjs = Pjs × tgφ= 0.9× 1.33 = 1.2 kvar
(8)、100m高扬程水泵
Kx = 0.75, Cosφ = 0.8, tgφ = 0.75 Pjs = 0.75 ×20 = 15 kW
Qjs = Pjs × tgφ= 15× 0.75 = 11.25 kvar
(9)、碘钨灯
Kx = 0.5, Cosφ = 1, tgφ = 0 Pjs = 0.5 ×1 = 0.5 kW
Qjs = Pjs × tgφ= 0.5× 0 = 0 kvar
(10)、灰浆搅拌机
Kx = 0.5, Cosφ = 0.55, tgφ = 1.52 Pjs = 0.5 ×2.2 = 1.1 kW
Qjs = Pjs × tgφ= 1.1× 1.52 = 1.67 kvar
(11)、建筑施工外用电梯
Kx = 0.2, Cosφ = 0.6, tgφ = 1.33 Pjs = 0.2 ×11 = 2.2 kW
Qjs = Pjs × tgφ= 2.2× 1.33 = 2.93 kvar
(12)、混凝土输送泵
Kx = 0.3, Cosφ = 0.7, tgφ = 1.02 Pjs = 0.3 ×32.2 = 9.66 kW
Qjs = Pjs × tgφ= 9.66× 1.02 = 9.85 kvar
(13)、钢筋调直机
Kx = 0.3, Cosφ = 0.7, tgφ = 1.02 Pjs = 0.3 ×4 = 1.2 kW
Qjs = Pjs × tgφ= 1.2× 1.02 = 1.22 kvar
(14)、钢筋切断机
Kx = 0.3, Cosφ = 0.7, tgφ = 1.02 Pjs = 0.3 ×7 = 2.1 kW
Qjs = Pjs × tgφ= 2.1× 1.02 = 2.14 kvar
(15)、UN1系列对焊机
Kx = 0.3, Cosφ = 0.7, tgφ = 1.02 Pjs = 0.3 ×25 = 7.5 kW
Qjs = Pjs × tgφ= 7.5× 1.02 = 7.65 kvar
(16)、钢筋弯曲机
Kx = 0.3, Cosφ = 0.7, tgφ = 1.02 Pjs = 0.3 ×3 = 0.9 kW
Qjs = Pjs × tgφ= 0.9× 1.02 = 0.92 kvar
(17)、总的计算负荷计算，总箱同期系数取 Kx = 0.8 总的有功功率 Pjs = Kx×ΣPjs = 0.8 ×
( 14+0.24+0.33+0.15+0.5+2.1+0.9+15+0+1.1+2.2+9.66+1.2+2.1+7.5+0.9) = 46.31 kW 总的无功功率 Qjs = Kx×ΣQjs = 0.8×
( 18.62+0.24+0.34+0.15+2.28+2.79+1.2+11.25+0+1.67+2.93+9.85+1.22+2.14+7.65+0.92 ) = 50.6 kvar 总的视在功率
Sjs = ( Pjs+Qjs )1/2 = ( 131.722151.382 )1/2 = 48.46 kVA 总的计算电流计算
Ijs = Sjs/( 1.732×Ue ) =48.46/( 1.732×0.38 ) =73.43 A 第四节、绘制临时供电施工图 1、临时供电系统图