There are all kinds of 'grounds' in this world and they are not all the same thing.
In general:
In residential buildings, the AC power has a Safety Ground/Protective Earth system.
Two wire components that have the 'Square within a Square' safety symbol are NOT to be connected to the Safety Ground/Protective Earth system. (see post #18) It can be dangerous to add a ground wire to their internal chassis.
In general:
In residential buildings, the AC power has a Safety Ground/Protective Earth system.
Two wire components that have the 'Square within a Square' safety symbol are NOT to be connected to the Safety Ground/Protective Earth system. (see post #18) It can be dangerous to add a ground wire to their internal chassis.
A family member who is a cardiologist has repeatedly told me about the electrical installations he has done in his summer home. And you always make the same mistake, calling neutral negative (-) and calling hot positive (+). In addition, on more than one occasion he repeats the same anecdote that he swears to be true: “On one occasion I took my car to my trusted mechanic and he told me: Hey, Dr., after all, there is not much difference between you and me, I change the engine valves and you change the heart valves. " And his answer was: "Hmmm, try changing the valves with the engine running" So should I go out on a limb and clarify for you the lack of knowledge you have between DC and AC? What if he gets offended? To each his own.
It would do the posters a world of good to compare the various requirements and wiring standards in different countries, such as the 110V lines with different split phase in the USA.
What is perfectly legal in one country is not allowed in another, and so on.
Add to that product liability insurance.
New LED monitors use an external brick supply, which the thing slimmer, but also avoids the maker having to use more safety functions in the design.
It is cheaper, and looks better...
What is perfectly legal in one country is not allowed in another, and so on.
Add to that product liability insurance.
New LED monitors use an external brick supply, which the thing slimmer, but also avoids the maker having to use more safety functions in the design.
It is cheaper, and looks better...
The most extraordinary invention regarding home electrical installations has been the differential circuit breaker. This device really saves lives, since it acts by cutting off the AC power supply in thousandths of a second even due to potential differences between ground and neutral... which are not the same...
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Joined 2003
Some people call it HOT... I call it phase because I have a minimal knowledge of polyphase AC.
The OP is talking about PE/Earth. It doesn't matter if we're talking about an AC or DC circuit, but the amp shown obviously runs on AC.
Neutral != ground even though in USA and Canada (and probably other places) they are bonded at the panel (and nowhere else downstream from that).
The OP is talking about PE/Earth. It doesn't matter if we're talking about an AC or DC circuit, but the amp shown obviously runs on AC.
Neutral != ground even though in USA and Canada (and probably other places) they are bonded at the panel (and nowhere else downstream from that).
That's not consumer... It's a niche "audiophile" (or audiophool depending on who you ask) product. Think Best Buy...
That is a USA standard Class AB amp. and the rules for the USA may be different from those in Europe.
Probably has a linear supply, so ground will act as EMI shield too if connected to chassis.
It is common for power tools to be double insulated, not that it has anything to do with audio, and the first insulation is generally the plastic housing.
The other insulation is inside, and unless you do it deliberately, or there is damage, you cannot come in contact with a live voltage.
FWIW, it may even be voluntary, and the extra wire may be a courtesy on the maker's part.
Not a big deal, just the extra cost of a socket and a small piece of wire inside the chassis...
That would make this a little confusing...
Probably has a linear supply, so ground will act as EMI shield too if connected to chassis.
It is common for power tools to be double insulated, not that it has anything to do with audio, and the first insulation is generally the plastic housing.
The other insulation is inside, and unless you do it deliberately, or there is damage, you cannot come in contact with a live voltage.
FWIW, it may even be voluntary, and the extra wire may be a courtesy on the maker's part.
Not a big deal, just the extra cost of a socket and a small piece of wire inside the chassis...
That would make this a little confusing...
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Joined 2003
"High end" maybe (low end of the high end), I think "niche audiophile" is a bit of a stretch. Besides, this thread is about an Emotiva amp. Both brands are internet order products in the same category title of your choosing.
In any case, as far as safety goes I'd be more concerned about a lacking CSA/UL/CE label than a missing ground connection. As you say, plenty of equipment goes without however is safe to use.
Ya I must have found something related on Google that in the website title boasted "audiophile" My bad.
Still... Internet order isn't consumer IMHO. You get that at the local big box stereo store..
I do consider Cambridge to be consumer, even though I can't find it at Best Buy, but so what? I'll bet 95% of the stuff they sell at https://www.baybloorradio.com is not grounded, either.
Some misconceptions in this thread. Modern cheap consumer grade devices are double insulated and made out of plastic. There is no metal surface that can be under voltage like older equipment had. Older equipment often with mains transformers always had a 3 pin IEC inlet (for those that state to have never seen that). If the modern devices would be built sturdy out of metal and still would have mains transformers we have an entirely different case. This Emotiva cheapo likely has a floating double insulated SMPS inside, maybe even an external power brick but built inside, that only has low voltage outputs with voltages that are declared to be safe.
In DIY many if not all use metal for casings and many if not nearly all are not able to build double insulated and have the device tested accordingly. So DIY devices in metal casings should have PE in 99% of cases. Make that 100% as it is not the builder only that uses the device so better not take any chance as the device may be sold later on etc.
It is not good to make PE a laughable matter and not even use the correct name. Any DIY metal chassis should have PE certainly when higher voltages than mains voltage are inside. It is laughing at ones own lack of knowledge.
In DIY many if not all use metal for casings and many if not nearly all are not able to build double insulated and have the device tested accordingly. So DIY devices in metal casings should have PE in 99% of cases. Make that 100% as it is not the builder only that uses the device so better not take any chance as the device may be sold later on etc.
It is not good to make PE a laughable matter and not even use the correct name. Any DIY metal chassis should have PE certainly when higher voltages than mains voltage are inside. It is laughing at ones own lack of knowledge.
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Yes, but remember there are different standards and naming conventions across the world to effectively make things safe.
I had never heard the term "PE" before I found this place.
Here, almost everyone including NEMA refer to "PE" as "Ground". That's why I posted about the different meanings of the word ground WRT to DIY and electric earlier on in the thread. 😛
"“The importance of ensuring that the grounding system provides a low earth impedance, and not simply a low earth resistance, must be understood. A spectral study of the typical waveforms associated with transient impulses, such as those characteristic of lightning and switching surges, reveals both high-frequency and low-frequency components. The high-frequency component is associated with the extremely fast rising “front” of the transient (typically less than 10 μs to peak current), whereas the low-frequency component resides in the long “tail” or follow-on current of the decaying impulse. High-frequency components are significant for inductive effects (induced voltages in the circuits), whereas low-frequency components are significant for energy effects (deposited energy in resistive elements).”
This of course refers to "Protective Earth" in other countries.
https://www.nemasurge.org/grounding/
I had never heard the term "PE" before I found this place.
Here, almost everyone including NEMA refer to "PE" as "Ground". That's why I posted about the different meanings of the word ground WRT to DIY and electric earlier on in the thread. 😛
"“The importance of ensuring that the grounding system provides a low earth impedance, and not simply a low earth resistance, must be understood. A spectral study of the typical waveforms associated with transient impulses, such as those characteristic of lightning and switching surges, reveals both high-frequency and low-frequency components. The high-frequency component is associated with the extremely fast rising “front” of the transient (typically less than 10 μs to peak current), whereas the low-frequency component resides in the long “tail” or follow-on current of the decaying impulse. High-frequency components are significant for inductive effects (induced voltages in the circuits), whereas low-frequency components are significant for energy effects (deposited energy in resistive elements).”
This of course refers to "Protective Earth" in other countries.
https://www.nemasurge.org/grounding/
Ground is at the secondary side of PSUs and Signal GND or Audio GND is connected to it. PE is at the primary side of PSUs and mains related. Recent regulations and papers speak of these terms.
I am not aware of North American regulations. In the EU everything is translated to English. In the past we used to have the same naming system but for many years ground is not the correct name anymore for PE as using "ground" for both PE and Audio GND is rather not practical as it are 2 different items and safety is involved. If the native English speaking countries use "ground" for both items we keep on having threads like these for many years to come.
In the DIY Audio ecosystem we can decide to do things clear and safe and use the correct terms that can make things simpler to new DIYers.
I am not aware of North American regulations. In the EU everything is translated to English. In the past we used to have the same naming system but for many years ground is not the correct name anymore for PE as using "ground" for both PE and Audio GND is rather not practical as it are 2 different items and safety is involved. If the native English speaking countries use "ground" for both items we keep on having threads like these for many years to come.
In the DIY Audio ecosystem we can decide to do things clear and safe and use the correct terms that can make things simpler to new DIYers.
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"Precision crafted in China"
Also likely no state company that tests all imported devices anymore. I have seen Yamaha devices that were supposed to be Class II but had a leakage current/voltage on the metal casing. As apparently no one except the manufacturer tests the device every device seems to be tested OK🙂 We call that "the butcher proves his own sold meat to be OK".
Of course the device should have been labeled Class II with the double insulated symbol. Also no CE marking. No alternative for well built DIY amplifiers I guess
Regards, the ground police
Also likely no state company that tests all imported devices anymore. I have seen Yamaha devices that were supposed to be Class II but had a leakage current/voltage on the metal casing. As apparently no one except the manufacturer tests the device every device seems to be tested OK🙂 We call that "the butcher proves his own sold meat to be OK".
Of course the device should have been labeled Class II with the double insulated symbol. Also no CE marking. No alternative for well built DIY amplifiers I guess
Regards, the ground police
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A nice thing about building my tube amplifiers in Hammond 1441 black boxes is that they are coated with a black polyester, not a thin paint. Even if the ground was faulty (old house? defeated?) it shouldn't shock.