KanedaK Posted November 14, 2011 Share Posted November 14, 2011 My amplifier went "poof" two days ago. Left channel LaScala ALK crossover fuse melted, despite the amp suposedly "protecting" the speakers in case of such an event. Replaced the fuse, and LS is playing just fine again. If there wouldn't be that fuse in there... i would be faced with repairing the power amp AND ordering a new K33 from Klipsch. I say DO NOT replace the fuse with wire for "sound quality" concerns! That fuse is PRECIOUS! Quote Link to comment Share on other sites More sharing options...
GBShade684 Posted November 14, 2011 Share Posted November 14, 2011 I work in the fuse "business". You would be surprised how many people call in pissed off when a fuse actually works as intended. "There's something wrong with your fuse! It keeps opening as soon as I turn power on." [:@] Quote Link to comment Share on other sites More sharing options...
merkin Posted November 18, 2011 Share Posted November 18, 2011 What fuses do you use in the universals. My son blew mine with some techno base crap. I replaced them with an auto fuse with less amps. I thought that if I went with less amps that they will blow sooner/easier. I haven't had a problem with them blowing to soon yet. They looked like auto fuses so that is why I used them. Quote Link to comment Share on other sites More sharing options...
GBShade684 Posted November 18, 2011 Share Posted November 18, 2011 Not sure what you mean by universals, but if you use a lower amperage rated fuse you will generally be safe, assuming the interrupting ability of the fuse is adequate. Some lower amperage rated fuses have a lower ability to interrupt short circuit current flow due to their constuction and materials. If this is the case and it sees to much then there could be trouble. However I don't think there is enough current available in most home applications because of the wire sizes found in most homes....for the most part the small glass fuses have an IR of around 1kA, but depending on the amperage and make it can vary from 35A to 10kA. Also the 110/120Vac systems in the US help a lot. Overseas you are looking @ 220/240Vac which is a lot harder on small fuses. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 18, 2011 Share Posted November 18, 2011 When he speaks of universals he is speaking of a certain type of speaker crossover. Just curious where you garnered the below Tid-Bit of information? Some lower amperage rated fuses have a lower ability to interrupt short circuit current flow due to their constuction and materials. If this is the case and it sees to much then there could be trouble. However I don't think there is enough current available in most home applications because of the wire sizes found in most homes....for the most part the small glass fuses have an IR of around 1kA, but depending on the amperage and make it can vary from 35A to 10kA. Also the 110/120Vac systems in the US help a lot. Overseas you are looking @ 220/240Vac which is a lot harder on small fuses I guess if 220 volts is hard on fuses....doing fuse coordination on a 1 megavolt line must be a real bear.... Quote Link to comment Share on other sites More sharing options...
GBShade684 Posted November 18, 2011 Share Posted November 18, 2011 When a fuse is interrupting a short circuit they do so by melting, which drives up the arcing voltage. The fuse has to safely contain the increased arcing voltage to pass testing, and to be a safe product. As system voltage increases so does arcing voltage. To contain increased voltages, the glass body can be switched to melamine, which is usually good to about 600Vac / dc. Above that you are looking at ceramic fuses. Also at those voltages a very fine and clean sand baked in sodium silicate is packed in the fuse to contain and quench the arc. Again, all this is a short circuit scenario. An overload of 200%-600% is just as difficult to quench, but now the IR rating is less important and the voltage rating is what is most important. As for the coordination, that is all the timing of the fuses. A downstream fuse must totally clear the fault current before the upstream fuse starts to unlatch. That is all about the amperage and the current limiting ability of the fuse. It is a real pain when talking about major short circuits where the fuses can be opening in less that a 1/2 cycle. The voltage, while still extremely important, does not play to large of a role here. Much of this knowledge comes from testing at high amperages and voltages. Just so happens I work at a location where this can be done. It's fun to watch them blow up fuses and circuit breakers sometimes. If anyone is interested I have quite a bit of free information that we provide. And you can always ask me as well. I'm relatively new to the game, about 1 of experience, but there are some cantankerous old timers here that have 35+... Quote Link to comment Share on other sites More sharing options...
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