RCD standing leakage budget
Gaano karaming standing leakage ang kayang dalhin ng isang RCD.
Reads AS/NZS 3000:2018 and AS/NZS 3760:2022. Tables checked 1 Oct 2026.
Subukan ang isang job 4
Nilalagyan ng halimbawang value ang bawat job. Palitan ang mga ito ng sarili mong value.
- Check the leakage on a home office RCDWhether a heat pump, four computers and a fridge stay within budget.
- Find why a workshop RCD tripsFour Class I tools at their test limit against a 30 mA RCD.
- Split an office over RCDs by leakageHow many RCDs six computers and six monitors need.
- Check a 10 mA RCD for childcareWhether a heat pump and chargers fit one 10 mA RCD.
Mga input
Worked example gamit ang mga default na input.
- Bansa
- New Zealand
- Rated residual current
- 30 mA
- Pinoprotektahan ang mga socket-outlet
- Oo
- Ang sinusuplayan ng RCD
- 3 row
Standing leakage
7.3mA
- Leakage sa RCD na ito
- Nasa loob ng one-third budget
- Badyet, isang-katlo ng rating
- 10mA
- Bahagi ng rated residual current
- 24.3%
- Mga RCD para mapanatili ang bawat isa sa loob ng badyet
- 1
Design aid lang ang resultang ito. I-verify ito laban sa kasalukuyang standard.
Mga hakbang ng kalkulasyon
- Heat pump: 1 × 3.5 mA na sinukat3.5mA
- Computers: 3 × 1 mA na sinukat3mA
- Fridge: 1 × 0.8 mA na sinukat0.8mA
- Standing leakageResulta7.3mA
- Badyet, isang-katlo ng rating10mA
AS/NZS 3000:2018 Cl 2.6.2.1 Note 1
- Maaaring mag-operate ang RCD sa itaas ng15mA
AS/NZS 3000:2018 Cl 2.6.2.1 Note 1
- Bahagi ng rated residual current24.3%
- Leakage sa RCD na itoNasa loob ng one-third budget
AS/NZS 3000:2018 Cl 2.6.2.1 Note 1
- Mga RCD para mapanatili ang bawat isa sa loob ng badyet1
AS/NZS 3000:2018 Cl 2.6.2.1
Tungkol sa calculator na ito
How this is calculated
Every item on a circuit leaks a little current to earth in normal use, through its insulation and through the filters on its supply. An RCD cannot tell that current from a fault. On one RCD the leakage of everything it supplies adds up, and enough of it trips the RCD with nothing wrong. AS/NZS 3000 asks for circuits to be split so the leakage expected in normal use is unlikely to trip the device. This tool adds up the leakage on one RCD and checks it.
You list what the RCD supplies. For each item you type a measured or maker's leakage, or you take the in-service test limit for its class from AS/NZS 3760: the most a Class I or Class II item may leak and still pass its test. The class limit is a worst case. Most items leak much less, so a measured figure gives a truer total.
The total is checked against two points of the clause's first note. The leakage should not pass one-third of the RCD's rated residual current, and an RCD may operate at any residual current above half of it. Past one-third the tool warns that unwanted trips are likely, past half that the RCD may trip, and at the rating it fails, because the RCD is made to trip there. It then places the items, largest first, on the fewest RCDs that keep each within the one-third budget, without splitting an item.
| Step | Table or clause | What it decides |
|---|---|---|
| Leakage of a Class I or Class II item | AS/NZS 3760 Table 2.1 | The worst-case leakage of an item with no measured figure |
| The duty to split circuits | AS/NZS 3000 Cl 2.6.2.1 | That normal leakage must not trip the RCD |
| The budget and the point it may trip | AS/NZS 3000 Cl 2.6.2.1 Note 1 | One-third and one-half of the rated residual current |
| Socket‑outlets on one RCD | AS/NZS 3000 Cl 2.6.2.1 Note 2 | A reminder that plugged-in items add leakage |
| A 10 mA RCD in New Zealand | AS/NZS 3000 Cl 2.6.3.3.2 Note 3 | Fewer socket‑outlets on one 10 mA RCD |
Worked examples
- A home office: a heat pump, three computers and a fridge leak 7.3 mA in total. That is within the 10 mA budget of a 30 mA RCD, so 1 RCD keeps it in budget.
- Four Class I power tools at their test limit could leak 20 mA, over half the rating, where the RCD may trip. Spread over 2 RCDs, each stays within its 10 mA budget.
- An office: six computers and six Class II monitors leak 15 mA, over the 10 mA budget. They need 2 RCDs.
- A heat pump and four chargers on a 10 mA RCD leak 6 mA, over half of 10 mA. The budget is 3.33 mA, so 2 RCDs keep each within it.
- An Australian laundry: washing machine, dryer and freezer leak 8.5 mA, within the 10 mA budget on 1 RCD.
Limits
The tool adds standing leakage, the current that flows all the time. It does not model the short surges as filters charge at switch-on, leakage from a frequency drive at its switching frequency, or a fault. Type F and Type B RCDs, and where each is needed, are for the RCD selection tool.
The class limits are the most an item may leak and still pass. A measurement with a leakage clamp on the circuit gives the real figure.
See also: RCD selection, RCD arrangement and Test and tag.
Mga tanong
Design aid ang resulta. I-verify ito laban sa kasalukuyang standard.
Bakit nagti-trip ang RCD kahit walang sira?
Bawat konektadong item ay may kaunting leakage current papunta sa earth sa normal na paggamit. Sa iisang RCD, nag-iipon ang leakage. Maaaring mag-operate ang RCD sa anumang residual current na higit sa kalahati ng rating nito, kaya ang 15 mA na normal leakage ay puwedeng mag-trip sa 30 mA RCD.
Gaano karaming leakage ang kayang dalhin ng isang 30 mA RCD?
Sinasabi ng AS/NZS 3000 Cl 2.6.2.1 Note 1 na hindi dapat lumampas sa isang-katlo ng rated residual current ang leakage: 10 mA para sa 30 mA RCD. Idinadagdag ng tool ang mga item at tinitingnan ang kabuuan laban dito.
Saan galing ang mga leakage figure?
I‑type ang sinukat na figure o figure ng maker para sa bawat item. Kung wala ka nito, puwedeng gamitin ng tool ang in-service limit ng AS/NZS 3760 para sa class ng item: 5 mA para sa Class I at 1 mA para sa Class II. Iyon ang pinakamalaking leakage na puwedeng ipasa ng isang item, kaya worst case ang mga ito.
Ilang RCD ang kailangan ko?
Inilalagay ng tool ang mga item mula sa pinakamalaki sa unang RCD na may puwang sa ilalim ng one-third budget. Hindi hinahati ang isang item sa pagitan ng mga RCD. Ang bilang ay ang pinakakaunti na nagpapanatili sa bawat RCD sa loob ng budget.
Aling mga item ang may pinakamalaking leakage?
Mga item na may filter sa supply nila, gaya ng computer, drive, heat pump at LED driver, at mga heating element habang tumatanda. Sukatin ang mga ito kung kaya: iba-iba ang leakage ng bawat modelo.
Mga worked example
Background
Mga clause at table na binabasa ng tool na ito
- AS/NZS 3000:2018 Cl 2.6.2.1Leakage on an RCD
- AS/NZS 3000:2018 Cl 2.6.2.1Standing leakage on an RCD
- AS/NZS 3760:2022 Table 2.1, 2.2, 2.3In-service test limits for electrical equipment
Bawat clause at table, kasama kung paano ito na-verify
Huling na-check ang mga table noong 1 Oct 2026.
Mga kaugnay na tool
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