Wow I'm glad you said that...I didn't realize this would double fuse my setups until then. Definitely a waste...
Josh Luthman Office: 937-552-2340 Direct: 937-552-2343 1100 Wayne St Suite 1337 Troy, OH 45373 On Mon, Mar 21, 2016 at 6:40 PM, George Skorup <[email protected]> wrote: > Let a surge suppressor be a surge suppressor. I will handle the > over-current externally (fuses, PacketFlux electronic, etc). > > On 3/21/2016 3:37 PM, Chuck McCown wrote: > > Yeah, I am coming to that conclusion I think. > > *From:* Forrest Christian (List Account) <[email protected]> > *Sent:* Monday, March 21, 2016 2:32 PM > *To:* af <[email protected]> > *Subject:* Re: [AFMUG] Fuse question > > > You need to look at the curve on the polyfuse. Because the trip is > related to heating which is related to current it will trip much faster in > many circumstances. ... however the trip current varies widely with > ambient temperature as well. > > I'm not convinced that you can actually find a polyfuse which will protect > Ethernet magnetics. > On Mar 21, 2016 4:14 PM, "Chuck McCown" <[email protected]> wrote: > >> The poe card would not be the cause, it would be the victim. The AP or >> wiring would be the cause. >> >> The polyfuse I am looking at takes 12 seconds to blow. Trying to >> protect the power supply and other loads in parallel. >> Not sure if that is fast enough to be of great value. >> >> If one AP shorts out, you don’t want it taking down others that are off >> the same power supply. >> >> *From:* Josh Luthman <[email protected]> >> *Sent:* Monday, March 21, 2016 2:07 PM >> *To:* [email protected] >> *Subject:* Re: [AFMUG] Fuse question >> >> >> Meh just replace the card if it's being troublesome. >> >> Josh Luthman >> Office: 937-552-2340 >> Direct: 937-552-2343 >> 1100 Wayne St >> Suite 1337 >> Troy, OH 45373 >> On Mar 21, 2016 4:05 PM, "Chuck McCown" < <[email protected]> >> [email protected]> wrote: >> >>> 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 <[email protected]> >>> *Sent:* Monday, March 21, 2016 2:02 PM >>> *To:* <[email protected]>[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]> >>> [email protected]> wrote: >>> >>>> Still leaning toward the polyfuse. Not a lot of room, fuses and fuse >>>> holders are more money. >>>> >>>> *From:* Bill Prince <[email protected]> >>>> *Sent:* Monday, March 21, 2016 1:51 PM >>>> *To:* <[email protected]>[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]> >>>> [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? >>>>> >>>>> >>>>> >>>> >>>> >>>> >>> >> >
