ᐅ Why are outdoor electrical outlets protected by only a 10A circuit breaker? Can this be changed?
Created on: 24 May 2023 10:18
T
Tolentino
Dear forum members,
I noticed early on that my outdoor sockets support less power than my indoor sockets (electric car caused the fuse to trip), but I didn’t look into it further at that time. Recently, I had issues with the shredder and the stone-cutting machine.
Annoyed by this, I finally checked the fuse box and found that both outdoor sockets are protected with 10 A fuses, while all the others are protected with 16 A fuses.
I have read that this is quite common, especially with switched sockets.
Both of my outdoor sockets are switched (recommended by the electrician, who did not inform me that this also means they support less power).
So, my first question is, why is this done? My assumption is that standard switches can only handle lower power (thermal load), so they are protected with lower-rated fuses to make sure the fuse trips before the switch burns out.
Can these be simply replaced? Can I hold the electrician responsible for not mentioning this? Is there any regulation or standard governing this? For example, that a standard type F socket (Schuko) should be rated for at least 3.5 kW, or does the electrician’s approach comply with best practices?
Thanks and best regards,
Tolentino
I noticed early on that my outdoor sockets support less power than my indoor sockets (electric car caused the fuse to trip), but I didn’t look into it further at that time. Recently, I had issues with the shredder and the stone-cutting machine.
Annoyed by this, I finally checked the fuse box and found that both outdoor sockets are protected with 10 A fuses, while all the others are protected with 16 A fuses.
I have read that this is quite common, especially with switched sockets.
Both of my outdoor sockets are switched (recommended by the electrician, who did not inform me that this also means they support less power).
So, my first question is, why is this done? My assumption is that standard switches can only handle lower power (thermal load), so they are protected with lower-rated fuses to make sure the fuse trips before the switch burns out.
Can these be simply replaced? Can I hold the electrician responsible for not mentioning this? Is there any regulation or standard governing this? For example, that a standard type F socket (Schuko) should be rated for at least 3.5 kW, or does the electrician’s approach comply with best practices?
Thanks and best regards,
Tolentino
Hello,
With an outdoor socket, however, you expect that a cable reel or a long cable will be connected to operate, for example, a lawn mower. In other words, the anticipated cable length to the device is significantly longer and especially hard to predict. Therefore, I don’t think the idea of protecting these sockets with a lower rating is entirely unreasonable. And it’s quite possible that the switches themselves are only rated for up to 10A.
And yes, Schuko sockets are rated up to 3.5 kW. But you should only load them that heavily in exceptional cases, not continuously.
Best regards,
Andreas
Tolentino schrieb:
Well, if all the other sockets are protected with 16A and only the two outdoor sockets (which are also switchable) are protected with 10A, it does suggest that the issue might be with either the socket or the switch. The cable length is not longer than for many other sockets.
With an outdoor socket, however, you expect that a cable reel or a long cable will be connected to operate, for example, a lawn mower. In other words, the anticipated cable length to the device is significantly longer and especially hard to predict. Therefore, I don’t think the idea of protecting these sockets with a lower rating is entirely unreasonable. And it’s quite possible that the switches themselves are only rated for up to 10A.
And yes, Schuko sockets are rated up to 3.5 kW. But you should only load them that heavily in exceptional cases, not continuously.
Best regards,
Andreas
The switches look like regular light switches. Before starting this thread, I also thought it was just the switch itself (meaning it’s only rated for up to 10A). I believe they are on a separate circuit; I need to check that later...
Anyway, my question is answered in the sense that the electrician could have a number of other reasons for protecting outdoor outlets with only 10A.
Anyway, my question is answered in the sense that the electrician could have a number of other reasons for protecting outdoor outlets with only 10A.
Most light switches are actually rated only for a nominal current of up to 10 A, so the electrician has done that correctly. Either you bridge the switch or install a 16 A rocker switch (for example, the Busch-Jäger 2000/2 US-101), then the electrician may also replace the circuit breaker with one rated for 16 A.
According to standards, a 16 A Schuko socket only needs to withstand the current for up to 30 minutes, if I recall correctly. Anything beyond that is uncertain... 10 A, however, are always allowed for continuous use.
According to standards, a 16 A Schuko socket only needs to withstand the current for up to 30 minutes, if I recall correctly. Anything beyond that is uncertain... 10 A, however, are always allowed for continuous use.
Tolentino schrieb:
But what if the socket can’t handle it? Will the 16A breaker trip, the RCD/FI switch activate, or will the house just burn down? A new socket outlet should reliably handle 16 A continuously, but over time the contacts can corrode, the fit can loosen, dirt can accumulate, and so on. This reduces the contact area more and more, leading to localized heating. In the worst case, the socket or even the external thermal insulation composite system (ETICS) into which it is installed can overheat and catch fire...
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xMisterDx25 May 2023 20:43If a Schuko socket must be able to carry 16A for 30 minutes according to the standard, this does not mean that manufacturers build their sockets so that they catch fire after 30 minutes and 2 seconds.
The cable length as an argument makes sense... but really...
A circuit breaker with a B-characteristic must trip at 5 times the rated current, which is 80A. That corresponds to about 2.875 ohms of cable resistance. If the resistance at the outdoor socket measuring point is 2 ohms or more, the electrician should become suspicious, because something is wrong. In a residential installation, I would consistently expect values below 1 ohm, no matter which socket I measure.
And a 1.5 mm² (approximately 1.6 square feet) lawn mower cable with a length of 50 m (160 feet) adds 0.6 ohms to that.
At 10 A, the circuit breaker must trip at 50 A... so I can afford 4.6 ohms of resistance.
Moreover, these are the values at which the circuit breaker is guaranteed to trip under all circumstances. At the earliest, it trips at three times the rated current...
The cable length as an argument makes sense... but really...
A circuit breaker with a B-characteristic must trip at 5 times the rated current, which is 80A. That corresponds to about 2.875 ohms of cable resistance. If the resistance at the outdoor socket measuring point is 2 ohms or more, the electrician should become suspicious, because something is wrong. In a residential installation, I would consistently expect values below 1 ohm, no matter which socket I measure.
And a 1.5 mm² (approximately 1.6 square feet) lawn mower cable with a length of 50 m (160 feet) adds 0.6 ohms to that.
At 10 A, the circuit breaker must trip at 50 A... so I can afford 4.6 ohms of resistance.
Moreover, these are the values at which the circuit breaker is guaranteed to trip under all circumstances. At the earliest, it trips at three times the rated current...
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