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On some stoves I've seen stickers stating that the stove doesn't need to be connected under the earth leakage... Which is rather confusing since we need to earth it in case of earth faults.

I'm just struggling to understand why a stove shouldn't be under earth leakage. Any information on this will be appreciated

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The sticker is not saying that the stove does not need to be earthed. It is saying that the stove does not need to be protected by an earth-leakage circuit breaker.

schematic

simulate this circuit – Schematic created using CircuitLab

Figure 1. A domestic fuseboard layout - Irish style.

Due to the amount of steam and spillages produced in cookers and stoves the likelihood of earth leakage is quite high. If the stove was protected by an earth leakage circuit breaker (ELCB / RCD / GFCI) nuisance tripping would become a problem. Because the stove is a fixed installation and more likely to be installed professionally the assumption is that the earth connection will be good and protect the chassis from reaching dangerous potentials. Similar decisions can be made for water heating, etc.

The highest risk of electric shock comes from portable appliances where cable damage, DIY errors, and accidents such as cutting through the hedge-trimmer cable, etc., are common and so earth-leakage detection is applied to all power sockets.

Interestingly lighting circuits can also be exempted on the basis that the number of accidents resulting from people stumbling around in the dark trying to find the fuseboard would exceed the number of electrocutions from lighting circuits which tend to be well out of harms way.

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Leakage is only for (products with) line filters to earth gnd and/or SMPS but not otherwise .

Internal Leakage and external faults of line power to grounded chassis are two difference scenarios.

Although a missing earth ground is an “external fault” that will induce a tingling current that is safe if an appliance does have <0.5 mA leakage, it is not the major line fault to chassis ground or “ground fault” that is a lethal fault. In that case the breaker trips and/or inbuilt fuse blows.

An open ground plus a line short to chassis is a double fault condition which is unprotected unless designed for this unlikely situation.

Stoves will use isolation transformers for low voltage to avoid the need for leakage noise suppression filters.

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  • \$\begingroup\$ I didn't downvote but I think the question is, "Why is earth-leakage protection (as in RCD / GFCI) not required for a stove?" \$\endgroup\$ – Transistor Jul 13 '19 at 8:05
  • \$\begingroup\$ There is no ground leakage in a stove as I described why. The other reasons is high current GFCI’s are silly expensive but worse yet stoves are inherently unbalanced with a single and a dual phase load for America. Thanks for the vote of confidence in advance. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Jul 13 '19 at 10:44
  • \$\begingroup\$ Also in America it is common for stoves to be unbalanced with no leagage current to ground because there may be 120V fuses for accessories and 240 Vac fuses for elements that use more current so it is INHERENTLY unbalanced by design so GFCI’s would cause a false failure ,!, if the question was specific to the North American or 60HZ stoves since all the bulbs are 120V. But even as I presumed it wasn’t I gave the correct reply. Don’t you see and agree. @Transistor \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Jul 13 '19 at 10:54
  • \$\begingroup\$ Surely both lives and the neutral (three conductors) would go through the GFCI CT in that case? \$\endgroup\$ – Transistor Jul 13 '19 at 11:00
  • \$\begingroup\$ Never. North American stoves never ever use GFCI’s for all 3 reasons I gave. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Jul 13 '19 at 11:04

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