Industrial 份指南
工业安装中的电动机回路、短路耐受能力和保护分级。
- 阅读约 3 分钟Generator fault current calculation at 400 VA 500 kVA 400 V standby set at 12 % subtransient reactance gives 721.69 A full load and 6014.07 A fault current, with the decay the figure leaves out.
- 阅读约 3 分钟IEEE 1584-2002: arc flash model and limitsWhat the IEEE 1584-2002 empirical model governs, where it stops applying, and a 400 V switchboard study that lands on 7.54 cal/cm² at 455 mm.
- 阅读约 3 分钟Dairy shed IDMT relay setting and gradingThree IDMT relays at a 3000 A fault, two grading margins and one curve inversion between the shed main and the farm incomer, read off the AmpSize relay engine.
- 阅读约 3 分钟Dairy shed motor current: 15 kW at 400 VFull load current, shaft speed, torque and DOL starting current for a 15 kW 400 V dairy shed vacuum pump motor, worked through the AmpSize motor engine.
- 阅读约 3 分钟IEC 60255-151: IDMT curve constantsWhat IEC 60255-151 governs, which curve sets the IDMT tool carries, and a worked grading pair on standard inverse that clears in 0.21 s and 0.74 s.
- 阅读约 5 分钟What size generator for a dairy shedSize a standby set for a dairy shed from its load list. The vacuum pump's start sets the size, then staggered steps, a drive and a soft starter shrink it.
- 阅读约 3 分钟Arc flash boundary at a motor control centreArcing current, incident energy and arc flash boundary for a 400 V MCC at 25 kA with a 0.1 s clearing time, and why the equipment type moves the result.
- 阅读约 5 分钟Cable tray fill for a plant room: a second tierLay ten multicore cables on a 300 mm perforated tray in one layer, see when it takes a second tier, and carry the grouping factor into the cable size.
- 阅读约 3 分钟Motor starting current for a 55 kW DOL startFull load current, DOL starting current, shaft speed and torque for a 55 kW four pole motor at 400 V, and what a soft starter or a VSD changes.
- 阅读约 2 分钟IP ratings for an outdoor point and a hosed shedWhich IP code an outdoor power point, a milking shed light and a hosed switchboard need, and why an IP67 light can fail where IP65 passes.
- 阅读约 3 分钟Starting a loaded conveyorA 22 kW conveyor that needs 120 % torque to break away. Why star-delta and a soft starter will not start it, and what a drive or autotransformer does.
- 阅读约 4 分钟Motor circuit for a 15 kW pump: DOL or star-deltaSize a 15 kW 400 V pump circuit: cable, breaker, contactor and overload relay. Compare DOL, star-delta, soft starter and drive starts.
- 阅读约 3 分钟Transformer secondary fault current for 500 kVAA 500 kVA 11 kV to 400 V transformer at 6 percent impedance, worked through to 721.69 A of secondary full load current and 12,028.13 A of fault current.
- 阅读约 3 分钟Factory power factor correction: 250 kW at 0.78A 250 kW factory load at 0.78 power factor lifted to 0.95. The kvar, the capacitor steps, the current saved, the kVA released and why the bank is detuned.
- 阅读约 3 分钟Fault level at a sub‑board, 300 kVA transformerWork the prospective fault current at a sub-board 45 m from a 300 kVA transformer, three-phase and phase-earth, and check 6 kA and 10 kA breakers against it.
- 阅读约 3 分钟Arc flash incident energy at a 400 V switchboardA 400 V board with 20 kA bolted fault and 0.2 s clearing gives 6.23 cal/cm² at 455 mm, an arcing current of 9.64 kA and a 1395.97 mm boundary.
- 阅读约 3 分钟IDMT curve grading for a 100 A feederTwo standard inverse relays at 2000 A give a feeder trip at 0.23 s, an incomer trip at 0.99 s and a grading margin of 0.76 s, read off one chart.
- 阅读约 4 分钟AS/NZS 3008.1.2 Tables 22 to 29: deratingWhat the derating tables govern, how ambient and grouping combine into one factor, and a 63 A feeder whose capacity falls to 78.85 A on 35 mm² copper.
- 阅读约 3 分钟AS/NZS 3008 Table 22 (now 3.33): bunched groupingAS/NZS 3008 Table 22 is the grouping table for bunched circuits, not a temperature table. The 2025 AU part calls it Table 3.33. Read it in the calculator.
- 阅读约 5 分钟AS/NZS 3008 vs BS 7671: cable sizing comparedHow BS 7671 and AS/NZS 3000 with AS/NZS 3008.1 size a cable, where they differ, and why a BS current rating never converts into an AS/NZS one.
- 阅读约 4 分钟AWG and the NEC for NZ and AU electriciansAWG sizes and the NEC set against AS/NZS 3000 and 3008.1. A gauge converts to mm², but its rating does not, and the NEC 3 % drop figure is only a note.
- 阅读约 3 分钟Motor full load current: 11 kW 400 V DOLFull load current, shaft speed, torque and direct on line starting current for an 11 kW four-pole 400 V induction motor, with the figures the tool returns.
本指南使用的计算器
- 发电机电流计算器根据发电机的 kVA 求出满载电流和故障电流。
- 电弧闪络计算器估算电弧闪络能量及其个人防护装备类别。
- IDMT 选择性计算器绘制反时限过电流继电器的动作曲线。
- 电动机计算器求出电动机的满载电流、启动电流和转矩。
- 根据负荷清单进行发电机选型根据负荷清单（含电动机启动）为发电机选型。
- 电缆桥架与梯架填充率桥架或梯架宽度、层数、kg/m 及成组系数。
- IP 防护等级表与解读解读 IP 代码，并求出某位置的最低 IP 要求。
- 电动机启动方式对比比较 DOL、星三角、软启动和变频启动。
- 电动机回路计算器单台电动机的电缆、断路器、接触器和过载保护。
- 变压器计算器计算变压器满载电流和阻抗。
- 功率因数补偿计算器求出提高功率因数所需的电容器 kvar。
- 短路电流水平计算器根据电源计算配电箱处的预期短路电流。
- 电缆截面计算器求出通过各项检查的最小电缆截面。
- 英制电缆截面换算器求出旧式英制电缆的保护装置额定值。