Australian Standards for fuse holder - Page 1
Forum section: electronics / projects

author: haxby
author_rank: Contributor
timestamp: October 09, 2024, 10:42:25 am
content: We bought this spot welder at work from a local Aussie supplier. The fuse holder is curiously labelled "insurance pipe" ha ha. But what is more interesting is that the fuse can simply be unscrewed and the live mains fuse can then be touched. Is there an Australian Standard that prohibits these types of fuses in an appliance?I don't see these fuses much anymore. The newer types of holders require a tool to open them, and even when opened, they disconnect the live terminal before sliding out the cartridge. Any pointers to a relevant AS is appreciated.

author: Terry Bites
author_rank: Super Contributor
timestamp: October 10, 2024, 03:34:20 pm
content: If you can touch the hot end the fuse in the holder then it's has been incorrectly wired inside the unit.UL 4248 and IEC 60127-5 are the two basic standards that govern fuse holders.

author: Someone
author_rank: Super Contributor
timestamp: October 10, 2024, 09:23:45 pm
content: AS3100 clause 3.6.1 d)and the general prohibition on there being exposed live parts (that hazard occurs regardless of which end/way-round the wiring is on those style of holders) user accessible (i.e. without tools).

author: TimFox
author_rank: Super Contributor
timestamp: October 10, 2024, 09:36:07 pm
content: With that type of fuse holder (typically used with 3AG or 5x20 mm cylindrical fuses), the trick is to connect the terminal farther from the panel to the hot terminal from the mains, and the panel end (which connects to the removable cap) to the load.By the time you can touch the fuse, it should be disconnected from live power.

author: Someone
author_rank: Super Contributor
timestamp: October 10, 2024, 09:59:23 pm
content: Quote from: TimFox on October 10, 2024, 09:36:07 pmThat was the prevailing norm, but since the user would be handling a bare fuse and their first instinct is to push the fuse into the hole (rather than clip it into the holder and use that as a tool to insert the fuse) that presents a significant, known, and demonstrated hazard. Not compliant in Australia and many other countriesany more.

author: TimFox
author_rank: Super Contributor
timestamp: October 10, 2024, 10:40:22 pm
content: Quote from: Someone on October 10, 2024, 09:59:23 pmThat may depend on the length of the holder. Littelfuse in US makes "shock-safe" holders for 3AG fuseshttps://www.littelfuse.com/media?resourcetype=datasheets&itemid=c3912242-b515-4837-8a86-99179d1a4a87&filename=littelfuse-fuse-holder-isf-datasheetthat meet IEC 65 and 257, as well as UL specs for US.The traditional Littelfuse holderhttps://www.littelfuse.com/media?resourcetype=datasheets&itemid=3bb34e5a-e8bb-4b76-85a2-10e66f47a665&filename=littelfuse-fuse-holder-342-datasheet.pdfmentions UL and CSA, but not IEC specs.I don't know the Australian regulations.

author: Someone
author_rank: Super Contributor
timestamp: October 10, 2024, 11:28:50 pm
content: Quote from: TimFox on October 10, 2024, 10:40:22 pmIf the insulation is long enough it should not matter which end is "live". Making safety distinctions between live and neutral is one of those things which is prohibited here and in many countries, yet people continue to claim "ok here so no problem for you".I wonder how that example holder works if the fuse is loose or inserted before the cap (people fishing with a tool to get the fuse out). But that heads off into more specific standards such as the machinery directive (which would apply to such a class of product).

author: floobydust
author_rank: Super Contributor
timestamp: October 11, 2024, 12:39:36 am
content: The fuseholder could be connected fine- another cause being the common chinese mistake of flipping incoming line and neutral.Incoming line (hot) connects to the appliance neutral which is very scary as it bypasses any fuse and even an on/off switch, keeping the PCB hazardous live.Also ensure the grounding is decent and can take the fault current, copper is expensive and many times it's too thin the wire and rivets over paint etc.

author: Someone
author_rank: Super Contributor
timestamp: October 11, 2024, 01:03:02 am
content: Quote from: floobydust on October 11, 2024, 12:39:36 amThe thread topic is explicitly "Australian Standards for fuse holder".Quote from: AS3100

author: floobydust
author_rank: Super Contributor
timestamp: October 11, 2024, 01:10:34 am
content: Can you post pics or part number of proper Australian (standard) chassis mount fuseholder, they seem to be "touch safe" no matter what as you describe.OP's 5x20 fuseholders are commonly used in North America but I suspect are an antique design.Also, you guys are using DPDT power switches?

author: themadhippy
author_rank: Super Contributor
timestamp: October 11, 2024, 01:19:24 am
content: Quote from: Someone on October 11, 2024, 01:03:02 amThe standards say many things,however many chinese manufacturers treat them as a suggestion,not a legal requirment

author: coppercone2
author_rank: Super Contributor
timestamp: October 11, 2024, 01:35:32 am
content: the people that insert the fuse first and holder second have some seriously unrealistic expectations about the quality of the mechanics lolHow about sticking a hook in there to try to extend the spring to fit a smaller fuse?

author: Someone
author_rank: Super Contributor
timestamp: October 11, 2024, 01:53:40 am
content: Quote from: themadhippy on October 11, 2024, 01:19:24 am[insert country here] manufacturer does indeed not care. Australian retailer however is bound to Australian safety requirements.Or shall we have another round of people suggesting things which are not applicable in Australia, regardless of what the OP asked for?

author: Someone
author_rank: Super Contributor
timestamp: October 11, 2024, 02:06:02 am
content: Quote from: floobydust on October 11, 2024, 01:10:34 amdouble pole mains switches were not mandated in the past, but are required in most designs these days. Switching of both poles isnotdone at socket outlets. The lack of switching both live and neutral wouldn't cause a failure through in service testing, but the accessible metal in the fuse holder would cause an appliance to be taken out of service immediately regardless of older standards allowing/ignoring it.I'd avoid that style of fuse holder entirely (other stricter standards such as machinery directive and 61010 make them impractical) and stick with a drawer type, rather than finding some obscure part that can meet the standards in that orientation.

author: floobydust
author_rank: Super Contributor
timestamp: October 11, 2024, 04:02:14 am
content: I actually have some of those fuseholders and they rely on hazardous live being the far inside terminal, for the disconnect.Kinda scary to look at up close, phenolic and molding is pretty dodgy.As I recall, they are a copied and cheapened Japanese design going back to the early 1980's.

author: coppercone2
author_rank: Super Contributor
timestamp: October 15, 2024, 12:02:33 am
content: Hmm I got another strike against the push in fuse holders,I took apart a old unit today. I noticed in the end I had a strange part, the plastic knob came off the cap, but the metal was attached, meaning you had a nice conductive prong sticking out.The ones that are recessed are better, because you would have to really work hard to touch the conductive part if the plastic fell off, but if its just a big thing sticking out of it, thats dangerous. A adhesive failure leaves a big conductive cylinder sticking out of the unit, perfectly connected into mains.While it might be dangerous to open a unit up to change a fuse, might it not be more dangerous to have exposed conductor on the back of the unit because some glue fell off?at least I won't get hurt if I need to move the unit. Easy to forget to unplug it, if you just wanna move it!

author: Haenk
author_rank: Super Contributor
timestamp: October 16, 2024, 06:16:33 am
content: It even has "Gratitude and purchase". That should make it trustworthy

author: haxby
author_rank: Contributor
timestamp: October 23, 2024, 09:23:17 am
content: Thanks to user name "Someone" in post no.2 for the heads up.The exact clause is attached.The fuse holder is dangerous regardless of how it is wired internally. A child or, really any person could easily unscrew the holder and get a nasty shock. Aussie distributor has been notified.

author: Someone
author_rank: Super Contributor
timestamp: October 23, 2024, 10:03:24 pm
content: Quote from: haxby on October 23, 2024, 09:23:17 amThey may come back and claim it's ok on that clause because "normal manner" is explained in a manual to not touch the metal bits, but other parts of the standard (and other applicable standards more clearly) state there should be no danger despite failing to follow instructions.