Matronics Email Lists :: View topic - Preliminary tests on modern fuse link wire

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Preliminary tests on modern fuse link wire

Matronics Email Lists Forum Index -> AeroElectric-List

View previous topic :: View next topic

Author Message

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Apr 23, 2020 10:45 am Post subject: Preliminary tests on modern fuse link wire

I ordered in some off-the-shelf fuse link wire

 with the intent of testing it for behavior under

 high fault currents.



 I've seen fuse-link wire that claimed to be

 made of some alloy of copper with a slightly

 higher resistance per square. The idea being

 that it would melt in a less spectacular manner

 than pure copper.



 The wire I received is pure copper with a

 an unique (Used to be Hypalon - now

 discontinued and replaced by CSPE) insulation.

 Okay, if one of these wires were tied in a

 bundle with other wires, would the fusing

 event propagate outside to the detriment

 of adjacent wires?



 Took a 9" piece of 20AWG fuse wire out to

 the shop and forced 100A through it.

 It took 3 or 4 seconds before any reaction

 was evident. Heard some hissing and then

 a rapidly growing jet of smoke through a couple

 of holes that formed in the insulation.



 99.5% of the insulation stayed intact save

 the 'vent' holes . . . pretty slick stuff.

 The smoke was voluminous but not particularly

 noxious.



 I think wires bundled with this stuff would

 be well isolated from the fusing event.



 I'll do more formal testing along

 with video coverage and fold that into

 a Shop Notes for the website. In the mean

 time, I am encouraged that this material

 offers an alternative to ANL or MANL fuse

 blocks in smaller systems.



 You may have noticed the fusible links in

 Z100 and Z101 drawings. I think those will

 stay. MUCH easier to fab than the earlier

 design shielded in Fiberglas. Cut of a chunk,

 splice it into the feeder with standard

 PIDG terminations and tie into bundle with

 other wires.



 

   Bob . . .

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

markfw

Joined: 28 Feb 2019
Posts: 27
Location: Seattle, WA

Posted: Sat Apr 25, 2020 10:18 am Post subject: Re: Preliminary tests on modern fuse link wire

Bob,



Thank you for doing this experimental research on fusible links. They appear to be an elegant and lightweight solution to my problem of where to mount an MANL fitting for my alternator b-lead in my cub.



I will be using a 40 amp externally regulated B&C alternator. My average load will be 30 amps.



I am using 8 AWG wire for the b-lead. The normal rule for link sizing is apparently to go up 4 steps in AWG size. This would suggest using a 12 AWG link. However the ampacity of 12 AWG wire is only 30 amps according to the National Electrical code.



This seems a little low, but I realize that fusible links will usually significantly exceed their nominal ampacity before "blowing".



What do you think in terms of link size?



Can you suggest a brand for Hypalon jacketed fusible links? It doesn't seem to be called out in many of the listings for fusible links.



How long should the link be? I assume that it should be as close the battery as possible?



Thanks.



Mark

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

markfw

Joined: 28 Feb 2019
Posts: 27
Location: Seattle, WA

Posted: Sat Apr 25, 2020 10:18 am Post subject: Re: Preliminary tests on modern fuse link wire

Bob,



Thank you for doing this experimental research on fusible links. They appear to be an elegant and lightweight solution to my problem of where to mount an MANL fitting for my alternator b-lead in my cub.



I will be using a 40 amp externally regulated B&C alternator. My average load will be 30 amps.



I am using 8 AWG wire for the b-lead. The normal rule for link sizing is apparently to go up 4 steps in AWG size. This would suggest using a 12 AWG link. However the ampacity of 12 AWG wire is only 30 amps according to the National Electrical code.



This seems a little low, but I realize that fusible links will usually significantly exceed their nominal ampacity before "blowing".



What do you think in terms of link size?



Can you suggest a brand for Hypalon jacketed fusible links? It doesn't seem to be called out in many of the listings for fusible links.



How long should the link be? I assume that it should be as close the battery as possible?



Thanks.



Mark

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

Display posts from previous:

	Matronics Email Lists Forum Index -> AeroElectric-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum