Floods And Electrics

[Blue Duck]

I'm not messing about in a feeder pillar. 630a @ 415v is vaporising stuff!

 

[apprentice87]

Yep, and never mind 0.4 of a second, they have fault clearance times of up to 100 seconds... Bit long to be hanging on to the cable waiting for the thing to shut off!!!

john...

 

[Tony S]

Can’t see any RCD’s in here and these are reckoned to be the safest type available. You can’t beat fitting big fuses.

Nothing automatic about the other end either.

 

[apprentice87]

Great photos!!!!

john..

 

[Tony S]

I thought that they could auto re-close HV 5 times before locking out?

It depends what they are set to. On OH lines they are downright weird.

1/ open on fault

2/ time delay

3/ reclose (hope the fault has gone away)

4/ open on fault

5/ time delay

6/ reclose (hope the fault has gone away this time)

7/ open on fault

8/ time delay

9/ reclose (we getting serious now, ignore any fault for a second or so and hope the fault burns clear or line fuses blow)

10/ open on fault

11/ lockout (give up!)

There’s more stages but that’s the rough idea.

I watched a fault on one of the old NWEB lines near our works. I phoned their control to get them to isolate. After an hour the pole was on fire, I went for a drink of tea.

 

[steptoe]

Many moons ago when we used to actually make the Xmas lights from proper festoon and screw the holders on, if there was a fault we would put a bloke on watch while we shoved in a 40amp, or bigger,  and see where the cable blew, 

Never failed to my knowledge,

 

[Lurch]

Used to do the same I've seen someone do that to clear faults on buried SWAs.

 

[apprentice87]

A chap I know used to work for SWEB. He told me that they often used this method to clear faults!!!!

john..

 

[kerching]

Used to do the same I've seen someone do that to clear faults on buried SWAs.

  

A chap I know used to work for SWEB. He told me that they often used this method to clear faults!!!!

john..

Burndown test!

In Saudi they have fuses up poles. If it is required to replace a blown fuse they go,and pick someone who is about to have their head or another part of their body cut off. They then get them to shin up the pole and put the fuse in. If there is still,a fault then they have saved having to clean the sword. No fault...happy bunny gets sentence reduced

Just praying

 

[Tony S]

2 x ¼” copper bar is a very good fuse replacement for fault finding.

Last time was to find a joint tree roots had damaged. The tree caught fire and fell over. Quicker than wandering around with a CAT scanner.

 

[revor]

Thanks to you all did not think my question would have got so much response. I've enjoyed reading the comments learnt a lot. Pretty impressive video of the 1200 KV breaker by Siemens my friend's son works for them, goes all around the world commissioning turbine generators given me an insight into this world.

 

[chris_k]

Does your friends son live in Nottinghamshire by any chance?

 

[revor]

No based in Manchester now but I think he did rent in Nottinghamshire a couple of years ago for a short time.