Hi Doug, As the link Rich provided from Littelfuse indicates, the international symbols come from IEC 60127-1. See the last page of this preview <https://www.sis.se/api/document/preview/568043/>, section 6.1.
On Wed, Mar 2, 2022 at 2:22 PM Richard Nute <[email protected]> wrote: > > > > > Here is some info: > > > > https://www.swe-check.com.au/pages/learn_fuse_markings.php > > > https://www.littelfuse.com/~/media/files/littelfuse/technical-resources/documents/reference-documents/littelfuse_5x20mm-iec-fuse-cap-marking_guide.pdf > > > > Rich > > > > > > > > *From:* Brian Kunde <[email protected]> > *Sent:* Wednesday, March 2, 2022 1:08 PM > *To:* [email protected] > *Subject:* Re: [PSES] Fuse designations > > > > I do not know where the information I have originally came from, but I got > this and have been using this for over 30 years: > > > > FF = Very Fast Acting > > F = Fast Acting (Common) > > M = Medium Time Lag > > T = Time Lag (Common) > > TT = Long Time Lag > > > > I got this from Bud Lang who was our Safety Guru at Heath Kit many years > ago. > > > > The Other Brian > > > > On Tue, Mar 1, 2022 at 5:33 PM Douglas E Powell <[email protected]> wrote: > > All, > > > > Over the years, I've seen various ways people include a caution or warning, > in their user documents or product labels, for replacement fuses. Similar > to: "replace only with same type and rating of fuse"; followed by a code: > T1.6AH250V. > And for those who may not understand the code, they may sometimes add in > parentheses some variant of "(1.6 Amp time-lag, ~250V, high breaking > capacity)". > > > So now to my question, US manufacturers sometimes use the phrase "SLO-BLO" > or "Slow Blow" instead of Time-Lag or Time-Delay. Are these terms commonly > used internationally and if so, are they clearly understood? > > > > I took some time to look up SLO-BLO and found it's a registered trademark > for Littelfuse going back to 1957, and it has been continuously renewed > since that time. > > > Incidentally, a German Engineer once told me the way he would designate a > fuse type for a variety of tripping characteristics was in this order from > very slow to very fast: TT1.0A250V, T1.0A250V, 1.0A250V, F1.0A250V, > FF1.0A250V. > > > > Thanks, -Doug > > > > > > Douglas E Powell > > Laporte, Colorado USA > > > > (UTC -07:00) Mountain Time (US-MST) > > > > > > - > ---------------------------------------------------------------- > > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to < > [email protected]> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > > Attachments are not permitted but the IEEE PSES Online Communities site at > http://product-compliance.oc.ieee.org/ can be used for graphics (in > well-used formats), large files, etc. > > Website: http://www.ieee-pses.org/ > Instructions: http://www.ieee-pses.org/list.html (including how to > unsubscribe) <http://www.ieee-pses.org/list.html> > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher <[email protected]> > David Heald <[email protected]> > -- Scott Aldous | Regulatory Compliance Manager | [email protected] | 650-253-1994 - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
