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Are Fuses in Plugs Directional ?

I always make sure the fuses in the hi-fi run North to South. I am amazed at how few on here know the importance of this. I also ensure the cats sleep on or by the hi-if facing East. This makes f-all difference but does give me a chance to contribute something that adds to the nonsense found on the web.
 
Just wondering if any hifi products come with MCBs rather than fuses? Given the foo around this sort of area, it's interesting to me that an MCB should in theory replace two contact points and a bit of wire with a mechanical switch (operated by a solenoid in a fault scenario) and so offer obvious benefits if this is the sort of thing you are bothered by. Also, it's the same tech that is used to get the power to your device, and i've not heard of people deriding the quality of the MCB in their consumer unit.

I've no idea whether this would meet, say, CE requirements, this is not my area, but i'm pretty sure i've seen resettable fuses on servers used in machine rooms.
 
Cesare said:
Just wondering if any hifi products come with MCBs rather than fuses? Given the foo around this sort of area, it's interesting to me that an MCB should in theory replace two contact points and a bit of wire with a mechanical switch (operated by a solenoid in a fault scenario)
Click to expand...
An interesting thought and I'd no idea MCBs were activated by a solenoid. By 'fault condition' I guess you mean overcurrent as fault to earth would be covered by an RCD. At a pure guess, I'd say that the manufacturing and operating tolerances of MCBs may not be feasible when specified at as low an amperage as your average case fuse. It would, if feasible, cost a lot more. Also, how would an MCB differentiate between kit requiring anti-surge (slow-blow) and fast-blow ?

With a bit of luck, I may have inadvertently addressed your query. :D
 
Mike Reed said:
An interesting thought and I'd no idea MCBs were activated by a solenoid. By 'fault condition' I guess you mean overcurrent as fault to earth would be covered by an RCD. At a pure guess, I'd say that the manufacturing and operating tolerances of MCBs may not be feasible when specified at as low an amperage as your average case fuse. It would, if feasible, cost a lot more. Also, how would an MCB differentiate between kit requiring anti-surge (slow-blow) and fast-blow ?

With a bit of luck, I may have inadvertently addressed your query. :D
Click to expand...
Yes, I was referring to the overcurrent condition as being the fault, the condition they are protecting against.

There are various different well defined characteristics, how much time needs to elapse before the MCB trips:

Differences and Similarities Between K Curve and D Curve Breakers

A Comparison of Thermal and Magnetic Tripping Characteristics of MCBs
info.e-t-a.com info.e-t-a.com

Just looking at RS, I see MCBs from 160mA, with there being typically 500mA intervals once you get into the few amps range. They even stock a 5kA option, which is I imagine aimed at datacentres or something like that.

The mechanism is a sensing circuit in parallel to the mechanical switch, so basically the current sense is out of circuit, much like how a multimeter measures current without affecting it's flow through the circuit. The characteristic curve is then calculated from this current flow measurement, so it can, say, trip if an overcurrent of 2x is detected for so many seconds, so you can avoid tripping on inrush current and that sort of thing.

I can see benefits if you are of the persuasion that anything in the way of current is a bad thing. Much more plausible than polishing your fuses :)
 
Cesare said:
Yes, I was referring to the overcurrent condition as being the fault, the condition they are protecting against.

There are various different well defined characteristics, how much time needs to elapse before the MCB trips:

Differences and Similarities Between K Curve and D Curve Breakers

A Comparison of Thermal and Magnetic Tripping Characteristics of MCBs
info.e-t-a.com info.e-t-a.com

Just looking at RS, I see MCBs from 160mA, with there being typically 500mA intervals once you get into the few amps range. They even stock a 5kA option, which is I imagine aimed at datacentres or something like that.

The mechanism is a sensing circuit in parallel to the mechanical switch, so basically the current sense is out of circuit, much like how a multimeter measures current without affecting it's flow through the circuit. The characteristic curve is then calculated from this current flow measurement, so it can, say, trip if an overcurrent of 2x is detected for so many seconds, so you can avoid tripping on inrush current and that sort of thing.

I can see benefits if you are of the persuasion that anything in the way of current is a bad thing. Much more plausible than polishing your fuses :)
Click to expand...
This is all well and good but can you get gold ones with beeswax inside?
 
paulfromcamden said:
This is all well and good but can you get gold ones with beeswax inside?
Click to expand...
I don't see why not. We have to first get the technology adopted, then there will be people selling 'aerospace grade' versions, then 'medical grade' versions, and that's when the market will open up to cryogenic beeswax enhanced versions assembled only during a full moon.
 
OK let's say a fuse is directional that still doesn't tell me which way to put it in the fuse holder on the board or in the plug.
My monos have got 2 internal fuses each there's nothing to indicate the 'flow' direction.
 
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