I don't why I bother replying, but you are just plain wrong. I'm sorry you insist on evaluating the problem from your local point of view. The OP is in the US. The device has a polarized jack on it. Presumably the cord that came with it has polarized plugs. The world does not revolve around Germany.
https://incompliancemag.com/article/double-fusing-or-fusing-both-sides-of-the-line
https://incompliancemag.com/article/double-fusing-or-fusing-both-sides-of-the-line
& don't mention that all of a cars metal bodywork is connected to the negative of the cars battery!.......
Like they also got confused why the Luxman amp has a "signal grounding" post on the rear, & its double insulated with no electrical earth!!...
Horror, danger!!..🤔
I added a "earthing post" to my double insulated Denon system...Why??.....Basically there was very little connectivity between the hi-fi & the planet, due to the thick Sorbothane feet under it. This causing the now "floating" metalwork of the case to act like the car body, & every time I touched the Denon I got a static shock!!! Basically as it is "floating" the "potential" of the Hi-fi is different to that of the planet. So this why you get static shocks, same with the car, the rubber tyres insulate it from the planet, open car door step on ground & touch car, & you get a static shock as you now "ground" or equalise the potential difference between the car & the planet.
Denon expected my hi-fi to "ground" to the planet via the aerial, but in the U.K most home FM aerials don't "ground". Luxman at least provide a nice grounding post for this!...Denon don't!!... So I connected an additional green wire in a star pattern to the separate Denon boxes & back to the same mains extension that the Hi-fi is plugged into via another 3 pin plug with only the earth pin connected to the green wire. All nice & safe, & no static & no hum loops!
Basically doing the same as when you actually touch the hi-fi & the room heating radiator...or planet....
There is also "x-bonding" which connects all water & gas pipes in a building together, & back to the mains "earth" to the main fuseboard. Mainly to stop electrocution of a person from a faulty appliance back via any exposed metalwork, taps, radiators etc..This will trip the RCD/MCB quicker on the live/neutral end as there is a quicker earth route. It also equalises out any "potential" differences between any metalwork & the planet...so again no static shocks.
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Actually reading that article is interesting...quotes:-
"The first question that must be addressed is: What fault protection is the fuse providing?
There are two kinds of faults: (1) phase-to-neutral (pole-to-pole) and (2) phase-to-ground.
(Note that a fuse cannot provide protection for a neutral-to-ground fault because, by definition, the neutral is grounded. In a neutral-to-ground fault, the neutral and ground conductors become parallel conductors. In accordance with Kirchoff’s Laws, the current in the neutral goes down, not up. Hence, the over-current does not occur, and a fuse cannot provide protection).-"
(Edit...Remember that the equipment the OP is talking about is double insulated so it has NO earth only live & neutral....so no "parallel conductors" problem between earth & neutral. )
More quotes:-
"In continental Europe, the socket wiring for the common 220 V, 16A plug is not polarized, and the equipment fuse location would be variable. In the UK and Australia, sockets and plugs are polarized, and the equipment fuse location would be constant.
The point is that each plug, socket, and building wiring is an independent situation which must be separately evaluated as to whether polarity reversal is possible. This, in turn, would make the equipment fuse location constant or variable.
For single-phase, single-voltage plug-and-socket-connected equipment, single fusing ONLY provides protection for both faults when polarity reversal is not possible. If polarity reversal is possible, then a single fuse can only provide protection against phase-to-ground faults 50% of the time."
The way that amp was made it has a directional socket placing the fuse on the neutral instead of the live on a double insulated piece of equipment which the mains voltage supplies a transformer to step down voltages to a PCB etc...If it fails the only path is down the neutral & the equipment is "double insulated" so no way is there a danger to the person touching it!!!.....It might not be belt & braces but it might have met the requirements for that piece of equipment being sold in different countries at that time!
I'll give you another problem....figure 8 connectors & sockets on double insulated equipment.....totally non-directional....no earth & still electrically safe & meets the relevant regs...
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[HEADING=3][HEADING=3][HEADING=3]leadbelly
Wow, you are good at reading details. How about the details in my post:Its technically safe. You have a double insulated piece of equipment which means that if there is any electrical fault the case will NOT go live.
When it does go faulty:- inside the case you will have live electricity going from the live wire through the transformer etc before its stopped by the blown fuse on the neutral side when it tries to "return". This means that if by any remote chance the live wants to find another return path it cannot go down the existing neutral as it is cut off by the blown fuse, so it has to find another path. This new path will cause a massive "earth leakage" to be seen by the RCD on your main fuseboard..(& trip it to OFF) ....this because there is now a total imbalance between the live & neutral wire from the mains to your faulty piece of equipment..
If the fuse was on the live side the path inside the case would be shorter i.e. from the live wire to the fuse....However in this situation the neutral is still connected, so if a fault occurred the live could find a new return path & back down the neutral which is still connected. Your main fuseboard RCD won't see this as much of a "fault"....so may not react in time, or may not react at all!...
There may also be safety X2 or Y2 caps which will be in place to prevent other live to neutral or live to earth faults, etc....regardless of which side the fuse is on!
The OP's amp is electrically safe with the internal fuse on the neutral side, & its double insulated by its internal electrical design.
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Looking at the Luxman L-507uX manual..the fuse is before the main switch, & the equipment is electrically safe!
It doesn't matter if its on the live or the neutral side as it is only powering the transformer & back-up transformer...& transformers usually don't mind live/neutral reversal.
I don't know what the OP is doing, but it appears this whole thread could have been avoided if they looked at their user manual!...Put the tools down & step away from the amp!!...
It doesn't matter if its on the live or the neutral side as it is only powering the transformer & back-up transformer...& transformers usually don't mind live/neutral reversal.
I don't know what the OP is doing, but it appears this whole thread could have been avoided if they looked at their user manual!...Put the tools down & step away from the amp!!...
I am just so turned on by this badboy Luxman designer that intentionally fuses the neutral only and intentially flouts a widely standard colour code for black and white mains wiring! Can I attend you guys' next meeting of the Luxman Engineer Appreciation Society? I'll bring my own lotion and tissues.
leadbelly
I am just so turned on by this badboy Luxman designer that intentionally fuses the neutral only and intentially flouts a widely standard colour code for black and white mains wiring! Can I attend you guys' next meeting of the Luxman Engineer Appreciation Society? I'll bring my own lotion and tissues.You haven't disproven what I state, as the Luxman design is electrically safe.......I'm not "into "Luxman..just I know electrical design & you're stating its dangerous based on your misguided thoughts, thus showing up your lack of knowledge in this area.
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