Substation Fuse

[linuxthefish]

What would the rating be for a substation fuse and has anyone ever seen one go while on a job? Had a mate asking me this earlier, and now i feel interested.

As i understand it goes: substation fuse > DNO fuse > CU?

 

[mechelec]

yes tony i am trained actually also i was a volunteer with the major incident support team at our local fire station for over a year,dont know why you seem to be getting wound up over this could it be someone has done something you haven,t perhaps?

meowwwww

 

[Guest111]

You being sarcy too mechelec? thought it was getting a bit elitist round here!

 

[mechelec]

You being sarcy too mechelec? thought it was getting a bit elitist round here!

Not me. Flippant maybe but never sarcastic.
Just taking the p**s really. Its like being on site here sometimes. You give a bit and take a bit back. No offence meant.

 

[Dcf]

About 10 years ago I was on a commercial job n we lost a phase.i knew it was in this subbie tucked away in a lane as I happened before.pointed the s&s lad in the right direction.he brought out this fancy current meter which clamped into the contacts of the j type fuse to measure the overload n then it shut down.i certainly wouldn't have stuck my hand in the subbie that's for sure.interesting stuff.best explosion witnessed?a 6000a acb feeding busbar trunking with every phase n neutral shorted to earth on the panel for the sake of 2foot of grommet strip!!!where was I? The other side of said panel!i think I got a suntan of that one.

 

[Knobhead]

You being sarcy too mechelec? thought it was getting a bit elitist round here!

Saucer of milk?
View attachment 10536

 

[mechelec]

About 10 years ago I was on a commercial job n we lost a phase.i knew it was in this subbie tucked away in a lane as I happened before.pointed the s&s lad in the right direction.he brought out this fancy current meter which clamped into the contacts of the j type fuse to measure the overload n then it shut down.i certainly wouldn't have stuck my hand in the subbie that's for sure.interesting stuff.best explosion witnessed?a 6000a acb feeding busbar trunking with every phase n neutral shorted to earth on the panel for the sake of 2foot of grommet strip!!!where was I? The other side of said panel!i think I got a suntan of that one.

Sounds like a fusemate. On a LV feeder fault these units are used in the place of the fuse. You fit an approriate size fuse in it, fit it on the Lv feeder stalks and it closes by remome control via a keyfob. It has a vacuum bottle type circuit breaker inside and saves having to bang fuses in onto a fault like the good old days. If the fault has cleared you then have to remove the fusemate and fit the fuse carrier and if you are quick and lucky the fault will not reoccur in the time it takes to remove the fusemate and replace the fuse.

 

[Knobhead]

Never used one, but seen them in action. Look a nice bit of kit. Anythings better than shove the fuse in!

http://www.kelvatek.com/fusemate.html

 

[mechelec]

Never used one, but seen them in action. Look a nice bit of kit. Anythings better than shove the fuse in!

http://www.kelvatek.com/fusemate.html

Thats the one. I know someone who forgot to pull the trigger in (which opens the internal breaker) and put it onto a feeder with a fault. It blew holes in the contacts on the fusemate oops
Have a look at the rezap. they are even better as they can be left on the feeder for intermittant faults and autoreclose up to 5 times before locking out. Good on faults because you can press the close button repeadedly to clear a fault (or blow the cable in half).

 

[Knobhead]

Good on faults because you can press the close button repeadedly to clear a fault (or blow the cable in half).

Good fun!
I think the best was a high resistance fault so a CAT trace was useless. Hours spent faffing about finally got to me, sod it copper links instead of 450A fuses, 1200A ACB as back up. Closed the switch and the ACB held in. The fault blew clear alright, it blew a tree clean out of the ground! Didn’t take a lot of finding after that. The roots had grown around a load of joints on the site of a former substation that had been moved, over the years the tree had been moving the joints.
The switch made a strange dull thud sound when I closed it.