Homeowner 份指南
棚屋、热水缸或电动汽车充电器需要多大的电缆。
- 阅读约 3 分钟Homeowner shed supply voltage drop over 60 mA 20 A single-phase supply running 60 m to a shed on 6 mm² copper, with the drop, the percentage and the maximum length the AmpSize voltage drop engine returns.
- 阅读约 5 分钟Ohm's law on a 3 kW water heater elementWork the current and working resistance of a 3 kW, 230 V water heater element with Ohm's law, why a cold meter reading is lower, then a 9 kW three-phase bank.
- 阅读约 5 分钟RCD tripping with no fault: add up the leakageAn RCD on a home office and kitchen trips with no fault found. Add up the standing leakage, check it against a third of 30 mA, and split it over two RCDs.
- 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Fixed heating maximum demand with Table C1Adding 7.5 kW of fixed heating to a house under Table C1 group D, the demand each group contributes, and the 80 A line that reg 59 draws.
- 阅读约 2 分钟A circuit chart for a house board with solarThe circuit chart and labels for a six-circuit house board with a solar inverter: ways, devices, RCDs, MAIN SWITCH, MAIN SWITCH SOLAR and a shared neutral.
- 阅读约 3 分钟Hot water cylinder cable size for a 3 kW elementA 16 A hot water circuit run 20 metres through wall insulation at 35 degrees, sized to 2.5 mm² with 17.86 A of derated capacity and 2.27 percent voltage drop.
- 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Reading the wiring in an older houseA 1970s New Zealand house with yellow actives, a green earth and a black neutral. What each colour can be, what may stay, and how to sleeve new terminations.
- 阅读约 1 分钟How far can 1.5 mm² run on a 10 A circuit?1.5 mm² copper on a 10 A curve C circuit can run 34.85 m before it reaches the 5 % voltage drop limit. The fault loop alone would allow 82 m.
- 阅读约 1 分钟How many amps can 1.5 mm² cable carry?1.5 mm² copper multicore PVC cable carries 16 A enclosed in air at 30 °C in NZ, so it takes a 16 A breaker. Clipped direct, it carries 17 A.
- 阅读约 1 分钟How many amps can 2.5 mm² cable carry?2.5 mm² copper multicore PVC cable carries 23 A enclosed in air at 30 °C in NZ, so a 20 A breaker protects it. Grouped with two circuits, it carries 16.1 A.
- 阅读约 1 分钟How many amps can 2.5 mm² carry in Australia?2.5 mm² copper multicore PVC cable carries 20 A enclosed in air at 40 °C on AS/NZS 3008.1.1:2025, exactly a 20 A breaker. Clipped direct, it carries 22 A.
- 阅读约 1 分钟How many lights on a 10 A circuit?In a home, AS/NZS 3000 Table C9 fills a 10 A circuit at 20 lighting points. A 21st point takes the sum over the circuit-breaker rating.
- 阅读约 1 分钟How many power points on a 20 A circuit?In a home, AS/NZS 3000 Table C9 fills a 20 A circuit at 20 single 10 A socket-outlets. A non-domestic installation counts each one at twice that.
- 阅读约 1 分钟Minimum cable size for a lighting circuitAS/NZS 3000 Table 3.3 sets a minimum of 1 mm² copper for circuits other than socket-outlets, lighting included. The load and the run often need more.
- 阅读约 1 分钟Minimum cable size for power pointsAS/NZS 3000 Table 3.3 sets a minimum of 2.5 mm² copper for a socket-outlet circuit. An exception can allow less, under conditions you must meet first.
- 阅读约 1 分钟What size cable for a 22 kW EV charger?A 22 kW three-phase EV charger on a 32 A circuit takes 6 mm² copper over 20 m, with 38 A of derated capacity and a 1.04 % drop. At 60 m it takes 10 mm².
- 阅读约 1 分钟What size cable for a lighting circuit in NZ?A 10 A lighting circuit in New Zealand takes 1.5 mm² copper over 30 m, with 16 A of derated capacity and a 4.3 % drop. A 16 A circuit takes 2.5 mm².
- 阅读约 1 分钟What size cable for power points in Australia?A 20 A power point circuit in Australia takes 2.5 mm² copper on AS/NZS 3008.1.1:2025, rated 20 A enclosed in air at 40 °C. Grouping pushes it to 6 mm².
- 阅读约 1 分钟What size cable for power points in NZ?A 20 A power point circuit in New Zealand takes 2.5 mm² copper enclosed in air, with 23 A of derated capacity. Ceiling insulation moves it to 4 mm².
- 阅读约 3 分钟Where can a home battery go? Garage wallsA garage wall that backs onto a bedroom, with a hot water cylinder nearby. See which AS/NZS 5139 location rules fail for a home battery, then fix each one.
- 阅读约 5 分钟Kitchen power points and the cooktop zonePlace power points and switches near a cooktop, an outdoor gas bottle and a gas vent. Check each distance to AS/NZS 3000 and hand the sink to the wet area tool.
- 阅读约 4 分钟Downlights in an insulated ceilingRe-insulate a NZ ceiling with downlights in it. Check which may be covered, which only abutted, which must come out, and the clearances and roof space sign.
- 阅读约 5 分钟12 V caravan cable: d.c. voltage dropA 12 V caravan feed at 30 A over 6 m, checked on 4, 6 and 10 mm² twin against the 10 % ELV limit, then a 48 V battery-to-inverter run.
- 阅读约 3 分钟Shed earthing on a 16 mm² submainEarth a NZ shed 30 m from the house on a 16 mm² submain. Compare an earth with the submain and a separate MEN with its own rod, and when each is allowed.
- 阅读约 4 分钟Solar battery size for a family home: 25 kWh a daySize a solar battery for a home that uses 25 kWh a day with an 8 kW array. Usable and nominal kWh, the bank, the inverter, winter solar and where it can go.
- 阅读约 5 分钟What size breaker for 4 mm² cable4 mm² copper enclosed in air takes a 25 A breaker, and 32 A fails at an Iz of 29 A. Grouping, a hot ceiling, insulation and a long run lower it.
- 阅读约 4 分钟RCD arrangement for a house boardCheck a New Zealand house board of eight circuits on two RCDs. See what fails with a fourth circuit on one RCD or both lights on one, and the AU change.
- 阅读约 4 分钟Total voltage drop: mains, submain and finalAdd the voltage drop of the consumer mains, a shed submain and a final subcircuit against the 5 % limit, and fix a long submain before the shed circuits fail.
- 阅读约 5 分钟Wire a bathroom: zones, IP ratings and the RCDA New Zealand bathroom with a 1.6 m bath and an open shower, worked through the AS/NZS 3000 Section 6 zones, the IP each item needs, the RCD and bonding.
- 阅读约 3 分钟Off-grid battery bank autonomy at 48 VA bach load list of 7600 Wh per day at 48 V needs 703.7 Ah of battery for two days of autonomy at 0.5 depth of discharge, worked step by step.
- 阅读约 3 分钟EV charger cable size for a 7 kW 32 A circuitA 7 kW EV charger on a 32 A dedicated circuit over 30 m needs 6 mm², with 38 A derated capacity, 2.85 percent voltage drop and 0.73 Ω loop impedance.
- 阅读约 4 分钟Domestic maximum demand with Table C1Assess the maximum demand of a New Zealand house from Table C1, group by group, with a worked example that lands on 52.61 A on a single-phase supply.
本指南使用的计算器
- 电压降计算器计算电缆线路的电压降并检查限值。
- 欧姆定律与功率V、I、R 和 P 中任意两项可求出其余两项。
- RCD 持续漏电流预算一个 RCD 可承受多少持续漏电流。
- 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。
- 最大需量计算器估算家用或非家用负荷的最大需量。
- 配电箱回路一览表制作配电箱回路一览表及其所需标签。
- 电缆截面计算器求出通过各项检查的最小电缆截面。
- 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。
- 电线颜色指南查找固定布线及软线（新旧均包括）的导线颜色。
- 最大回路长度计算器电压降和故障回路所允许的最长线路。
- 现有回路检查检查已安装回路：电缆、保护装置、电压降和 Zs。
- 回路负荷计算器统计终端分支回路可承载的点位数。
- 最小导体截面查询查阅回路允许的最小导体截面。
- 蓄电池位置检查器依据 AS/NZS 5139，检查家用储能电池可以安装在哪里。
- 插座位置检查灶台、煤气瓶、通风口或水槽附近的插座。
- 筒灯净距检查IC、CA90 或 Non‑IC：绝缘材料可以接触灯具吗？
- 附属建筑接地棚屋接地：可与分支干线共用接地，或采用独立的 MEN。
- 太阳能储能电池计算器为光伏晚间负荷选型家用储能电池。
- RCD 配置检查检查每个 RCD 的回路数及照明分配。
- 总电压降计算器将进线、分支干线和终端分支回路的压降相加，并对照 5 %。
- 潮湿区域分区检查器求出近水区域的 Section 6 分区、IP 及 RCD。
- 蓄电池组计算器根据负荷计算蓄电池组容量及续航时间。