Well, they have their downside. A real fuse will be easier to notice when it is blown. A poly fuse just cuts the current way down. More of a troubleshooting issue than anything else.
But, if a fuse is blown, then you have to fix the circuit and find a replacement fuse. I do have LEDs and by unplugging the short circuit cable the LED should come back to full brightness. Just thinking out loud here. Want to make the right choice. From: Josh Luthman Sent: Monday, March 21, 2016 2:02 PM To: [email protected] Subject: Re: [AFMUG] Fuse question Cheaper to run a polyfuse...why bother asking??? Josh Luthman Office: 937-552-2340 Direct: 937-552-2343 1100 Wayne St Suite 1337 Troy, OH 45373 On Mon, Mar 21, 2016 at 4:01 PM, Chuck McCown <[email protected]> wrote: Still leaning toward the polyfuse. Not a lot of room, fuses and fuse holders are more money. From: Bill Prince Sent: Monday, March 21, 2016 1:51 PM To: [email protected] Subject: Re: [AFMUG] Fuse question Most of ours are now the DIN-mounted double feed that uses the 5x20mm glass fuses. However, we also have a few legacy sites that use the automotive blade fuses. If something new came along, we would use what it uses. bp <part15sbs{at}gmail{dot}com> On 3/21/2016 12:47 PM, Josh Luthman wrote: We already stock 5x20mm fuses so keeping with the same form factor would be nice. Anyone else using those same DIN clip fuse holders have the same. Josh Luthman Office: 937-552-2340 Direct: 937-552-2343 1100 Wayne St Suite 1337 Troy, OH 45373 On Mon, Mar 21, 2016 at 3:40 PM, Adam Moffett <[email protected]> wrote: I have no strong opinions sir, but if it's a replaceable fuse I do like the automotive blades because every gas station has them. On 3/21/2016 2:42 PM, Chuck McCown wrote: I am considering adding a fuse to a new version of my rack mount POE surge suppressors. I know many of you like PTC resettable solid state fuses. I don’t recall ever designing one in to anything. Maybe I did on a phone device years ago, but that would have been to satisfy a regulatory agency only. Studying up on them I learn that if you have a 1 amp “hold current” the “always trip” current is 2 amps. Not like a fuse, which is pretty well guaranteed to trip at any current over the rating if you wait long enough. For a polyfuse, if your load is one amp, you have to have a design value of greater than 1 amp hold current. But then it takes double that to actually trip.. And then there is leakage current required to keep it in the tripped condition. It does not totally break the circuit. They are fairly inexpensive compared to glass fuses and fuse holders. Could do auto blade fuses too. Not sure I have the room for anything but a polyfuse though. Anyone have strong opinions about this?
