ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Burning out of return(white) side of 120volt rec
by crselectric. 06/14/19 02:15 AM
Video door bell causing chime activation of coil
by JoeTestingEngr. 06/13/19 12:43 PM
Troubleshooting Voltage Drop Across Relay
by gfretwell. 06/09/19 11:49 AM
Apple Recalls Three-Prong Wall Plug Adapters
by Admin. 06/05/19 09:06 PM
New in the Gallery:
What is this for?
Plug terminals
Who's Online Now
0 registered members (), 6 guests, and 17 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Blown Up Fuse #189986
11/01/09 05:52 PM
11/01/09 05:52 PM
Admin  Offline
Joined: Oct 2000
Posts: 3,547
I never heard what the actual cause was. So anyone's guess is as good as mine. It look's like an electrical arc might of melted the metal at the tops of the fuses a little bit.

Tristan S.

[Linked Image]

Tools for Electricians:
Re: Blown Up Fuse [Re: Admin] #189987
11/01/09 08:09 PM
11/01/09 08:09 PM
HotLine1  Offline

Joined: Apr 2002
Posts: 7,091
Brick, NJ USA
Damage appears to be on the line side of the fuse, possibly a line to ground fault. Or, severe overheating condition within the switching mechanism. Note there appears to be no damage on the load side terminations, or the load side of the fuse.

Re: Blown Up Fuse [Re: HotLine1] #189988
11/01/09 08:18 PM
11/01/09 08:18 PM
renosteinke  Offline
Cat Servant
Joined: Jan 2005
Posts: 5,316
Blue Collar Country
Every fuse has a limit of how many amps it can safely interrupt. Exceed that, and this is what happens.

All it takes is a dead short - and more fault current available than the fuse is rated to interrupt. That's what all those 'fuse classes' are all about.

It's possible that the wrong type of fuse was used, but more likely that the fuseholder selection itself wasn't correct.

It's also possible that the PoCo made some changes - a new transformer, etc., that led to more current being available then there was before.

Re: Blown Up Fuse [Re: renosteinke] #189995
11/02/09 01:39 AM
11/02/09 01:39 AM
frenchelectrican  Offline
Joined: Feb 2003
Posts: 939
Wi/ Paris France { France for ...
The AIC rating will affect the safety blow thru the fuse so if the system was upgraded the AIC will go up and the fuse stay the same good chance it will really blow apart like you see at the photo ditto with breakers blink

I know Bussman fuse company did have a link or chart for AIC rating and it is good details in there.


Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)

Re: Blown Up Fuse [Re: frenchelectrican] #190005
11/02/09 11:01 PM
11/02/09 11:01 PM
HotLine1  Offline

Joined: Apr 2002
Posts: 7,091
Brick, NJ USA

Bussmann Fuse has a wealth of info available...

They have a few really good videos of fault current testing. Also, the 'Safety Basics' materials are informative and interesting.

Re: Blown Up Fuse [Re: HotLine1] #190356
11/12/09 08:07 PM
11/12/09 08:07 PM
mikesh  Offline
Joined: Jun 2006
Posts: 613
Victoria, BC, Canada
I have seen heat related causes where a poor connection destroyed the fuse but never exceeded the ampere rating of the fuse. The tube is consumed over time from heating usually at the ferrule ends and eventually the guts get exposed. A fault cannot clear because all the arc quenching material has fallen out. The fact that the fuse tube is consumed on the top is part of my guess and i would look for silica sand in the bottom of the fuse holder to bolster or kill my theory. Also look for heat blued conductor or insulation damage like melting at the terminals. A Fault seldom causes slow failures and this looks like a heat failure with a fault at the end.


2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Member Spotlight
Amish Country, PA
Posts: 46
Joined: March 2013
Show All Member Profiles 
Top Posters(30 Days)
Admin 2
Popular Topics(Views)
255,726 Are you busy
191,693 Re: Forum
181,473 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.020s Queries: 15 (0.004s) Memory: 0.9790 MB (Peak: 1.1289 MB) Zlib enabled. Server Time: 2019-06-18 05:06:52 UTC