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I do. It goes B A N G ! !
I went to a house just before I retired that had had two wired in the wrong way round.
What a spectacular explosion!
12v MR11 Low Voltage lighting tripping RCCB
- Thread starter J5
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I do. It goes B A N G ! !
I went to a house just before I retired that had had two wired in the wrong way round.
What a spectacular explosion!
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What dictionary was that? The definition is incomplete. Here is the correct definition from Wikipedia:
A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. Electromagnetic induction produces an electromotive force within a conductor which is exposed to time varying magnetic fields. Transformers are used to increase or decrease the alternating voltages in electric power applications.
I might add that even that is incomplete, as there are current transformers, and also isolating 1:1 transformers that don't change the voltage.
That's Wikipedia - you could have written it.
What's alternating voltage?
What's alternating voltage?
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I didn't write it.
If you don't know what alternating voltage is you shouldn't really be on this forum.
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I have found with my RCD's switch mode power supplies can cause them to trip without there being a fault as such. It is really the fault of the RCD not the switched mode power supply, mine are rather old fitted in around 1994 and not electronic. The spikes caused by even a poor connection before the RCD can cause them to trip, and resetting one can cause the next door one to trip. All RCD's are not equal.
My first thought however was you have connected line ~ earth instead of line ~ neutral. You can draw 3.45W line ~ earth without tripping a RCD so without a load the electronic transformers would not be taking enough power to trip a RCD. What I would do is connect to a simple plug and test, if they work OK on the plug then clearly a wiring fault.
Because we use AC it is possible cables have a capacitance or inductance which can cause what is seen as an imbalance. In a perfect world we would not run just the line to a switch as this adversely affects the impedance of the feeder, but with 50Hz this is not really a problem. However the simple test with a plug would show if there is some thing odd with wiring.
We tend to call a new device after the device it replaces, be it an electronic transformer, or an electronic ballast, the word electronic is enough to tell most what it really is. Like saying we are taking our car for an MOT which shortly after the MOT was introduced became the DOE and now the DVSA but we still say we are taking our car for a MOT even when that no longer exists. In the electrical trade we still call a wire wound device which isolates a supply, but does not transform the voltage an isolation transformer. That's live. Only when it causes problems, like when traditionally a device which regulates current is called a driver, and because a driver was used with LED's which in the main are current devices, then some one called a device which feeds the driver with a regulated voltage a driver as well. That is an accident waiting to happen. But calling it an electronic transformer rather than a AC power supply is not really a problem. However it does not help finding the problem.
So step one test it with a plug. Lets see the results please.
My first thought however was you have connected line ~ earth instead of line ~ neutral. You can draw 3.45W line ~ earth without tripping a RCD so without a load the electronic transformers would not be taking enough power to trip a RCD. What I would do is connect to a simple plug and test, if they work OK on the plug then clearly a wiring fault.
Because we use AC it is possible cables have a capacitance or inductance which can cause what is seen as an imbalance. In a perfect world we would not run just the line to a switch as this adversely affects the impedance of the feeder, but with 50Hz this is not really a problem. However the simple test with a plug would show if there is some thing odd with wiring.
We tend to call a new device after the device it replaces, be it an electronic transformer, or an electronic ballast, the word electronic is enough to tell most what it really is. Like saying we are taking our car for an MOT which shortly after the MOT was introduced became the DOE and now the DVSA but we still say we are taking our car for a MOT even when that no longer exists. In the electrical trade we still call a wire wound device which isolates a supply, but does not transform the voltage an isolation transformer. That's live. Only when it causes problems, like when traditionally a device which regulates current is called a driver, and because a driver was used with LED's which in the main are current devices, then some one called a device which feeds the driver with a regulated voltage a driver as well. That is an accident waiting to happen. But calling it an electronic transformer rather than a AC power supply is not really a problem. However it does not help finding the problem.
So step one test it with a plug. Lets see the results please.
But how about the ones with a miniature PCB transformer in them that is part of the SMPS.
Ok, technically it's more than a simple transformer and falls in the category of a power supply and not a mains 50hz transformer, but still...Then what do we call milli and micro volts? Extra Extra Low Voltage?
Maybe your old faulty power supplies were failing between the primary and secondary side and were on their way out.
Good to know, funny enough earlier today I was wondering what would happen if you connected a 9V battery across the mains?
Don't suppose you know the answer to that do you?
No, they are also ELV.Then what do we call milli and micro volts? Extra Extra Low Voltage?
You've been here 4 years, and have never once seen this: [wiki]Electrics%3AVoltage-Bands[/wiki] ?
Yes I know it's ELV really, I was making a subtle reference to the fact that having millivolts and <50V AC in the same category band is a bit stupid. But there again, when does your average electrician need to worry about millivolts and micovolts. To an electrician who works on mains equipment and to a electrical engineer who works on logic level stuff, terms can mean different things.
When he's looking at voltage drop figures...
Sure, if were talking about cable resistances and permissible voltage drop over long distances. And yes there's going to be a point where a the allowed voltage drop will be exceed by the tiniest percentage and one could run into a citation where they have exceeded the allowed voltage drop for a given situation by 1 milli or micro volt for example.
But one would normally work with a margin of error, let alone a cables/circuits resistance and thus voltage drop is going to change over time due to conditions such as temperature, humidity, oxidation, etc... what is going to result in a difference more than a few milli volts, so one would presumably round up to the nearest volt when working out the voltage drop.
Go into a PCB repair shop who repair logic level stuff, and ask them what they class as low voltage. I bet they will not say equal and above 50V AC/120V DC.
Yes, but that is just cable characteristics.
Again, that is giving the millivolt drop per amp per meter for a given cable size; (230v /100) * 0.05 = 11.5v drop allowed for all circuits expect lighting circuits.
i.e. If one works out that their non lighting circuit will have a voltage drop of 11.501V for the designed load and length of the cable used, one will likely (not saying they should) only take the first two digits after the decimal place and ignore the 1 on the end of 11.501 as one could classify the 1 on the end within the margin of error what could and likely will minutely change over time.
By the books is one thing, but in the real world there is a thing called a margin of error. If you want to be 100% complaint, just round the voltage drop up to the 2nd digit after the decimal place.
Hence a few milivolts difference is within the margin of error and thus would likely be ignored or rounded up. Don't tell me that you have taken several tests and just taken the highest/lowest value to what ever was required and ignored the last least significant digit.
Plus a good circuit design will never come borderline close to the permissible allowed limit/s anyway.
Again, that is giving the millivolt drop per amp per meter for a given cable size; (230v /100) * 0.05 = 11.5v drop allowed for all circuits expect lighting circuits.
i.e. If one works out that their non lighting circuit will have a voltage drop of 11.501V for the designed load and length of the cable used, one will likely (not saying they should) only take the first two digits after the decimal place and ignore the 1 on the end of 11.501 as one could classify the 1 on the end within the margin of error what could and likely will minutely change over time.
By the books is one thing, but in the real world there is a thing called a margin of error. If you want to be 100% complaint, just round the voltage drop up to the 2nd digit after the decimal place.
Hence a few milivolts difference is within the margin of error and thus would likely be ignored or rounded up. Don't tell me that you have taken several tests and just taken the highest/lowest value to what ever was required and ignored the last least significant digit.
Plus a good circuit design will never come borderline close to the permissible allowed limit/s anyway.
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