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ed-ectrician

One of the first things i learnt was, if you pull a dno fuse, remove the load first.

Of course i never pull fuses but that's another story...

Has anyone ever pulled one accidentally or otherwise with a load on it? What happened?!?! Bloke i work with said it's fine but he's ex military so likes to be known as a bit of a 'crazy bloke' if u know what i mean!

Not saying all ex army are like this but you do get a few like this dont you?!

Ed
 
Depends on the size of load and inductive content .... anything from a little crackle to the larger industrial racking gear that can kill you outright if PPE not used.
 
If you pull a fuse which has a load on it, there will be an arc.
The size of the arc will depend on the size of the load.
The greater the load, the greater the arc.
The main problem associated with this, is that the contacts could become welded together, or at the very least damaged.
 
I knew it would arc, was wondering how crazy the arc would be in a flat with say 35 amps running thru it?
 
I've pulled 400A rewireable fuses under load. I realy don't know what the problem is.

If you do pull them don't dither about, grab it, pull it!

If it's three phase then you have to pull two at the same time. I always went for yellow and blue, red usualy has more load due to idiot electricians loading one phase.
 
If you pull a fuse which has a load on it, there will be an arc.
The size of the arc will depend on the size of the load.
The greater the load, the greater the arc.
The main problem associated with this, is that the contacts could become welded together, or at the very least damaged.

So basically what we're saying here Mr.OP is that....tell your army friend to go to a factory, make sure everything is switched on and operational and then pull the fuse. :biggrin:
 
Domestic is relatively small even with the inductive loads found and this will limit the effect at most to a little flash and crackle ..... only minimal chance of maybe getting a burn or blinded from the vaporised metal and minute shrapnel.

Assuming no short circuit is present!!!! when refitting the DNO fuse that we all know this is just hypothetical ;)
 
Bloody nora yes under fault conditions would be nothing short of hilarious

I've see it done ed, it's not funny loading you're mate in to the ambulance.

No Way No How can you beat that fuse. Just stand back and wait for the pop.

It's more like a dull thud really with HRC fuses. Bit of a let down.
 
Now removing the explosive pellet out of an Air Bomb firework and having a spark from the fire accidently exploding it is a real bang...... and nearly lost the use of my hand and had temporery hearing loss..... when your a teen you do stupid stuff but believe it or not it never stopped me trying again .... im grown up now and spend my career trying to prevent big bangs...ironic in a sense.
 
i've see it done ed, it's not funny loading you're mate in to the ambulance.

No way no how can you beat that fuse. Just stand back and wait for the pop.

It's more like a dull thud really with hrc fuses. Bit of a let down.

and dont forget partial blindness
 
if you worried pull it fast. the chance is if your pulling it then the load wont be that great as you would have checked your not about to turn a computer or like like off...

pulled hundreds of these hypothetical fuses and never had a problem with load over it. putting back in they often crackle but turn to put them in straight so both sides hit the contacts at the same time.

- - - Updated - - -

if you worried pull it fast. the chance is if your pulling it then the load wont be that great as you would have checked your not about to turn a computer or like like off...

pulled hundreds of these hypothetical fuses and never had a problem with load over it. putting back in they often crackle but turn to put them in straight so both sides hit the contacts at the same time.
 
Another update:

Inserting the fuse under load.
Most fuse holders have a terminal shield. It has two uses. First to protect you from the live terminals, the second isn’t to well known. If you rest the fuse holder against the shield in line with the fuse contacts, you then put you’re palm against the holder and push up and in. You can’t react and pull the fuse if there’s a fault. Hold it by the handle and you reaction is pull back. Then in the words of Ellie Goldburg. “Anything can happen!”
 
Last edited by a moderator:
There was a belief at one time, that the high UV emitted by the arc, could weld contact lenses to the cornea of the eye.
Fortunately this is incorrect, although in some places the wearing of contact lenses whilst welding is still prohibited.
Not to forget the flash has vapourised hot metals and can on rare occasions get in your eye and damage your eyesight if not blind you...... imalways a fan of welders flash.... had it several times and now im more or less immune to it but its very worrying when it happens for first time :/
 

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