HRC fuses - Page 1
Forum section: electronics / beginners

author: orbiter
author_rank: Frequent Contributor
timestamp: April 15, 2010, 04:23:45 pm
content: Hi AllAnybody know if it's possible to get HRC fuses which are the same physical size as the small glass variety that come in multimeters? My new meter (not so cheap) came with the glass fuses and I would like to replace them with the HRC type if this is possible.Any advise pleaseRegardsorb

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 17, 2010, 02:03:19 am
content: First advice ... read this first.http://en.wikipedia.org/wiki/Fuse_%28electrical%29

author: MTron
author_rank: Regular Contributor
timestamp: April 17, 2010, 03:56:32 am
content: Well, i guess it would be easier if we knew what multimeter it was (Make and model). I mean, HRC fuses are all well and nice, but if the internals of the multimeter are not up to spec, then a HRC fuse wont make it a whole lot safer to work with on high power circuits.

author: Simon
author_rank: Unknown
timestamp: April 17, 2010, 09:52:52 pm
content: I think maybe the HRC fuse will not blow apart and damage the multimeter, but if the multimeter is not protected so that it does not explode if say you put 250 volts into it on the ohms range the HRC fuse won't be that much use to you

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 17, 2010, 10:43:58 pm
content: Any fast acting fuse , are better that any slow fuse ...And about protection , in multimeters , yes they do help ... and if you are in doubt about what to use,just get the amperes rating , that makes you feel safe ..And about protection at "ohms range".. against.. "Mains 220" measurements , get fusible probes with 500mA fast acting fuses .This is what I recommend for " extra " safety .

author: Unknown
author_rank: Unknown
timestamp: April 18, 2010, 01:29:58 am
content: There are HRC (not as high as the ones Fluke use) in 5x20 format, I have some in front of me now: Wickmann No. 181 (160mA slow blow, 1500A AC interrupt capability). You'll want a fast-acting one with more capacity for a DMM, obviously.Quote from: Kiriakos-GR on April 17, 2010, 10:43:58 pmHow's that going to help, the input impedance is still 10Mohm in resistance mode, the only moment the current will exceed 500mA is after the FET is blown. It might just prevent an explosion, but is unlikely to save the meter.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 18, 2010, 02:31:25 am
content: We are not trying to save the horse, but the " Reckless " rider

author: orbiter
author_rank: Frequent Contributor
timestamp: April 20, 2010, 08:09:47 pm
content: Quote from: MTron on April 17, 2010, 03:56:32 amMeter is a new Voltcraft VC920 which came with 2 glass fuses. I was just wondering whether it would be worth changing the fuses for HRC ones. Mainly just as a precaution in case a fuse blew and instead of it blowing hot glass around the inside of the meter possibly damaging other parts, a couple of HRC fuses would just rupture & prevent any excess internal damage?regardsorb

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 20, 2010, 09:47:28 pm
content: Practically , if you replace the current fuses with equal rating " fast acting " ,I would call it as an useful " upgrade " .If your cables and probes looks "weak" , you can also replace them with better ones,as another useful " upgrade ".And this is the end of the road.Tips like : Use it properly and carefully ... or ... do not drop it down ... or ... Dot Not Even Think to Share your DMM with another person ( By giving it even for few hours, to some one else to use it ) ,are the rest " must do " that will guarantee you own safety.

author: orbiter
author_rank: Frequent Contributor
timestamp: April 25, 2010, 11:04:06 pm
content: Good advice Kiriakos. My meter won't be being used by anyone else so that's a good startAlso the advice regarding fast acting fuses is good also. Not sure if the device has those already though. Would I be able to tell if they were fast blowing fuses that were fitted by the way they look, or is there a symbol or rating I could check for?Thanksorb

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 26, 2010, 12:06:24 am
content: There is an easy way to find out, if their main body are made of glass , are the common slow type.The fast acting one, haves ceramic body . ( there in no way to see the wire in them) .check this picture ... since 80s Metrawatt was using this type.(the visible ones are the spare ones )( I had visit your home page , great job , well done )

author: Unknown
author_rank: Unknown
timestamp: April 26, 2010, 09:25:39 am
content: Quote from: Kiriakos-GR on April 26, 2010, 12:06:24 amI believe you're confusing fast-acting vs. slow-blow and high interrupt current vs. normal interrupt current. I've seen lots of fast-acting fuses with a glass body and a single wire inside. The only way to distinguish them is that fast-acting fuses are usually marked 'F' on the metal end caps (eg. F 1A, from German 'flink'), while slow-blow fuses are usually marked 'T' (from German 'trage'). Fast-acting fuses are usually cheaper than slow-blow fuses.High interrupt current fuses do usually have a ceramic body (and I think it's filled with something like sand to extinguish arcs), as opposed to the glass body filled with air that's used for regular fuses. These are available as both fast-acting and slow-blow.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 26, 2010, 12:06:35 pm
content: Quote from: alm on April 26, 2010, 09:25:39 amWell you are probably speaking about low voltage fuses max 220V ..The multimeters use higher voltage rated ones, and at this level, all of them are ceramic.It will be a true surprise for me, if you point out a link or a picture with one 600V fuse made of glass.And now about picking the right one ... you just need the faster , you will have to research one or two or three product catalogs , so to find it .The above MM can do 750V AC nominal , max 1000V .

author: Unknown
author_rank: Unknown
timestamp: April 26, 2010, 12:25:09 pm
content: Quote from: Kiriakos-GR on April 26, 2010, 12:06:35 pmMy claim was that fast-acting or slow blow does not determine whether the body is glass or ceramic, not that all fast fuses are made of glass.It's is true that most higher-voltage fuses are also made from something like ceramic, although there's always the exception that proves the rule:Cooper/Bussmann TDC11 and TDC10 series, courtesy of the Mouser parametric search. TDC10 is fast acting, TDC11 is slow blow, depending on the current, they are rated up to 1000V. Interrupt current is just 10x rated current, though.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 26, 2010, 12:52:44 pm
content: Dear friend .. I do not care about such exceptions ... courtesy of the biggest thief in the world wide market , who sells one damn fuse for 8-14$ .I will Buy my fuses from Europe or China , and I will get the best that I can find , always normally priced..But if this makes you feel any better , I will admit that you have won this little debate.But now you have to buy and pay the damn fuse ... no matter the costOr else I have won

author: Unknown
author_rank: Unknown
timestamp: April 26, 2010, 01:49:13 pm
content: Quote from: alm on April 26, 2010, 09:25:39 amQuote from: Kiriakos-GR on April 26, 2010, 12:06:35 pmQuote from: alm on April 26, 2010, 12:25:09 pmQuote from: Kiriakos-GR on April 26, 2010, 12:52:44 pmThere's just no way to debate with you. Every time I disprove a claim, you turn around and claim something different, or put words in my mouth (I never claimed that high-voltage glass fuses were anything but an exception). The purpose of my post was to prevent confusing beginners with wrong information: 'for fast acting fuses, just look for the ceramic ones', not to start an argument. If it makes you happy, feel free to say you won this debate. It's off-topic for this thread, so I'll stop here.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 26, 2010, 02:00:22 pm
content: ok lets stop it here this named as "debate" or conversation , and I will give the safest tip for the young ones.1) If you do not trust the manufacturer who made your Goods , do not buy them !!2) The one who has choose your Fuses , on your device , he is an provedTrueelectronics engineer,working in team with many others , and he is about 50 years old bold and short.And called asEXPERTbecauseHE IS...So ,as long you are not an expert in such matters, do not try to become one , because of a topic in a forum.Crystal clear view , and 100% understandable ..