Pulling main fuse and smart meters

[OnlQQker]

While obviously we cannot condone any sort of fuse-pulling activity on these forums, anyone who is doing that sort of work really should be trained to recognise when to leave it to the DNO. Basically anything looking damaged or very old would be an instant red flag.

Also when working on anything that is energised and very high energy you absolutely should be wearing suitable PPE to minimise the damage an arc-flash incident might case. For my own sins (which are many and varied, but not usually involving the DNO) I have ended up with this sort of stuff as a starting point:

TC42ESBJ | Penta White Safety Helmet with Chin Strap, Adjustable | RS

uk.rs-online.com

CATU CGM-00 Mechanical Insulated Gloves (500V) - Choice of Size

Insulated below 500V Work without leather overgloves Several sizes available

www.tester.co.uk

Click Flame Retardant Coverall (CFRBS) | PPG Workwear

Click Flame Retardant Coverall (CFRBS) Welders coverall. Protects against heat and flame. Concealed stud front to neck. Discounted prices.

ppgworkwear.co.uk

The visor is the obvious defence against something going BANG! in your face, but you need gloves to stop both the shock risk and the 3rd degree burns that an arc pushing out 1/4 MW can do in tens of milliseconds. Also you really don't want your cloths going on fire or melting to your skin, so natural fibres and welding-style overalls are a start!

For bigger stuff you get fancier PPE that is rated for much higher energy, etc, and hearing protection is also recommended for the blast wave you can get. True, you look like a worker battling Chernobyl clean-up, but folk doing that really ought to have a full risk assessment and establish the arc-flash energy values to chose it.

Something like this chap was wearing

 

[LukeD]

Ive got one to do in a Book shop. Told them i love Life too much .They can Call the DNO and arrange for a main Pull fuse /isolator .Done a few live tails before and it makes me really nervous

 

[Welchyboy1]

Something like this chap was wearing

Crazy video
Scary stuff
it amazes me at the end when they start dumping snow on an electrical fire to put it out

 

[LukeD]

Crazy video
Scary stuff
it amazes me at the end when they start dumping snow on an electrical fire to put it out

I would have done my pants

 

[OnlQQker]

Crazy video
Scary stuff
it amazes me at the end when they start dumping snow on an electrical fire to put it out

Electricity can be extremely scary stuff.
The power of it is unreal

 

[Welchyboy1]

Electricity can be extremely scary stuff.
The power of it is unreal

Glad I do mostly domestic work!

 

[7029 dave]

Arc proof PPE and visor really is a must when messing around with cutouts, yes we have all pulled without but its daft.

 

[HappyHippyDad]

While obviously we cannot condone any sort of fuse-pulling activity on these forums, anyone who is doing that sort of work really should be trained to recognise when to leave it to the DNO. Basically anything looking damaged or very old would be an instant red flag.

Also when working on anything that is energised and very high energy you absolutely should be wearing suitable PPE to minimise the damage an arc-flash incident might case. For my own sins (which are many and varied, but not usually involving the DNO) I have ended up with this sort of stuff as a starting point:

TC42ESBJ | Penta White Safety Helmet with Chin Strap, Adjustable | RS

uk.rs-online.com

CATU CGM-00 Mechanical Insulated Gloves (500V) - Choice of Size

Insulated below 500V Work without leather overgloves Several sizes available

www.tester.co.uk

Click Flame Retardant Coverall (CFRBS) | PPG Workwear

Click Flame Retardant Coverall (CFRBS) Welders coverall. Protects against heat and flame. Concealed stud front to neck. Discounted prices.

ppgworkwear.co.uk

The visor is the obvious defence against something going BANG! in your face, but you need gloves to stop both the shock risk and the 3rd degree burns that an arc pushing out 1/4 MW can do in tens of milliseconds. Also you really don't want your cloths going on fire or melting to your skin, so natural fibres and welding-style overalls are a start!

For bigger stuff you get fancier PPE that is rated for much higher energy, etc, and hearing protection is also recommended for the blast wave you can get. True, you look like a worker battling Chernobyl clean-up, but folk doing that really ought to have a full risk assessment and establish the arc-flash energy values to chose it.

What would be the causes of an arc flash with regards pulling a domestic main fuse. Plus, have you ever known anyone who has witnessed or seen one (again, domestic cut out).
Ps.. I've just ordered an arc flash helmet

 

[pc1966]

What would be the causes of an arc flash with regards pulling a domestic main fuse. Plus, have you ever known anyone who has witnessed or seen one (again, domestic cut out).

The most obvious one is an old/weak cutout that fails during the pull and allows the supply L-N to short, or the supply cable is badly damaged inside so movement/strain triggers a short.

The less obvious one is inserting the fuse on to a live fault, your immediate reaction is to pull your hand away but withdrawing the fuse is going to expose more arc to you. Ideally you line the fuse up and then with open palm push it in firmly. If faulted, let the fuse blow and contain the energy.

Ps.. I've just ordered an arc flash helmet

Hopefully you never need it!

But if you do it can save you from serious injuries: some limit to UV light on eyes, IR burns to skin, splattered molten metal, and a little protection against inhaling metal vapour.

Or even just banging your head in confined space, accident or not. I sometimes use mine in the attic in case of getting my head cut on nails holding slates in place.

 

[pc1966]

Just to add, the PPE is not only for fuse-pulling activities, really any when working live such as removing DB covers in situations when powering down a whole installation is not workable (unlikely domestic, I can't see any reasonable situation when you would not power off the CU first), or testing when anything of significant energy could be disturbed/shorted.