Is an Isolation Switch Required

[Keith@SparksFly]

I just wanted to check with more experienced guys on the requirement for an isolation switch. I have been asked to replace a CCU and I had a quick look at the job before doing all the pre testing that is needed. There is no Isolation Switch or Henley Block, just the 16mm old colour tails coming out of an old style rotary meter. The providers seal is still on the incoming fuse.
What is the best way to proceed? Do I need to get the provider or DNO to install an isolation switch and henley block or is there another way of doing it?

Many thanks.

 

[telectrix]

you could fit a D/P 100A isolator yourself, but would need the seal fairy to perform a vasectomy on the DNO fuse .

 

[Pete999]

Not that I have ever done it, not ever it's a sin, cut the seal?? fit and isolation switch yourself, but I never said that, someone else is typing this

 

[telectrix]

and if you want new tails, then the fairy needs to do the meter seals. ( replacements obtainable from the ebay fairy).

 

[Des 56]

The providers seal is still on the incoming fuse.
What is the best way to proceed? Do I need to get the provider or DNO to install an isolation switch and henley block or is there another way of doing it?
Many thanks.

 

[bigspark17]

How close is the cu to the meter? If your cutting the seal may aswell tails your new 25mm tails into the meter and use your main switch in the cu as single point of isolation. No need for another switch in the installation then.

 

[ChrisElectrical88]

I have dropped my snips and accidentally cut hundreds of seals. It's more rare to see a seal sealed than cut!

 

[The Ghost]

If you want isolation to change CU you are best advised to get the DNO to provide this. However the cost may be prohibitive. So you will have to pray for a fairy. There are dangers associated with pulling main fuse and the fact it is an offence, so you are between a rock and a hard place on that one. In the south west it costs £150 ish to isolate would the customer stand that? As to is an isolation switch required.... I would say definitely yes.

 

[westward10]

I have fitted many a main switch to replace a CU and never cut the seal or pulled a fuse. Who said that not me surely and don't call me Shirley.

 

[Pat H]

I've had the DNO fit an isolator for me (supplied by me) if you can find a reason to have them on site. So a DNO fuse upgrade or new tails and they are there just ask them.

 

[Keith@SparksFly]

Thanks Guys, thats pretty much what I thought, but thought I'd ask. I shall prey for a fairy!

 

[westward10]

Thanks Guys, thats pretty much what I thought, but thought I'd ask. I shall prey for a fairy!

Be careful what you pray for now

 

[Midwest]

It would be an idea for you to check your DNO's policy on electricians removing their main fuse & cutting their seals to do so, if you work in predominately one area.

My DNO SSG, permit electricians registered with a scheme, to do the above. They also provide temporary seals for re-sealing afterwards.

Whilst I agree removing a main fuse can be dangerous in certain circumstances, a dynamic risk assessment should negate that, and should not be done under load.

 

[SparkyChick]

As has been suggested, if there is a valid reason for them to attend (loose tails for example) then just get setup with an isolator ready and get them in to attend the safety issue. The guys I've encountered from WPD have all been great and very helpful.

 

[Wxmspark]

I'm my experience - some DNOs are happy to install a 100A isolator FOC -i Usually write a brief note for the customer to say to the DNO as request has to come from customer.

Failing that I know some DNOs are happy to scheme registered sparks to cut the seals & reinstate (Scottish power- have a PDF on their website allowing this)