SPD’s requirements in electrical non domestic installations

[Ian1981]

Well just as I thought I had this spd requirements down I attended the Niceic tech talk, with a speaker from the jpel/64 panel who is mainly responsible for the requirements of SPD’s and go figure a manufacturer of the product.
So I learned that installing a type 1 device at the origin and type 2 devices at downstream distribution boards is not enough ( where a LPS is required)
SPD’s are required wherever the zonal interface is penetrated from the outside (zone 0)
So coaxial cables, telecommunication cables, cables from one building to another etc all require protection where they enter the building and enter the building from zone 0.
As an example he showed us an estate where it consisted of over 40 individual SPD’s.
Bit of a ball ache really so I’m off to re-train as a plasterer as it’s less hassle

 

[Ian1981]

 

[Ian1981]

 

[ruston]

Well just as I thought I had this spd requirements down I attended the Niceic tech talk, with a speaker from the jpel/64 panel who is mainly responsible for the requirements of SPD’s and go figure a manufacturer of the product.
So I learned that installing a type 1 device at the origin and type 2 devices at downstream distribution boards is not enough ( where a LPS is required)
SPD’s are required wherever the zonal interface is penetrated from the outside (zone 0)
So coaxial cables, telecommunication cables, cables from one building to another etc all require protection where they enter the building and enter the building from zone 0.
As an example he showed us an estate where it consisted of over 40 individual SPD’s.
Bit of a ball ache really so I’m off to re-train as a plasterer as it’s less hassle

That would not help . Your trowel and float would need one.

 

[Strima]

I did an LPS course a few years ago and TBH we could have spent another week going through SPDs then...

It really adds to the price of a job when you have lots of zones within building, I do telecoms and it is a complete nightmare to do properly and to get the customer to pay for it.

 

[Ian1981]

My tiny mind is blown as I did not fully appreciate the actual requirements of the LPZ system and all the different cables entering the different zonal interfaces and the shear amount of SPD’s required

 

[ruston]

I did an LPS course a few years ago and TBH we could have spent another week going through SPDs then...

It really adds to the price of a job when you have lots of zones within building, I do telecoms and it is a complete nightmare to do properly and to get the customer to pay for it.

Out of interest do you get many strikes on the masts?

 

[Strima]

Out of interest do you get many strikes on the masts?

Not as often as you’d think. Most common cause of damage is from induced voltage from strikes further away, this is where the SPDs come into their own.

A direct strike on a building even with LPS can cause a significant amount of damage, luckily we don’t see many high magnitude strikes in the UK, ours are pretty feeble.

 

[Nigel]

I am aware of the requirement for all services and incoming cables to be protected against surges from lightning in the lightning BS but all this is not within BS7671 so not a part of our remit surely?

 

[Ian1981]

Thing is the regulations cover cables upto 1000 v A.C and 15000 v D.C so cables in this bracket are fair game.

It was very much an eye opener

 

[AJshep]

I carry out maintenance on a large CNC enginerring factory, Wire new machines, change damaged DOL etc and maintain service.

Although I try to work within the regulations (to the best of my knowlege) the original design was not carried out by me, its intresting to know where I would stand from a legal point of view if something were to happen like a fire or major damage to machines due to wrongly selected type of SPD or lack of SPDs. and of course om top of that we have AFDDs

Domestic settings are fairly simple but maintaining an older installation which is in constant services worries me, if you do the math SPDs should be installed in most suburban settings in the UK especially if your withing a few 100 mtrs of the substation. And AFDD are recommended in the BBB but if someone didnt recommended one and say something burnt down due to and arc or expensive machinery got damaged due to a surge then I am sure the insurance company's would get the contractor nailed to the cross even if that part of the installation was nothing to do with them.

 

[DefyG]

You cant be accountable for what was designed and installed there beforehand but for any future work SPD's AFDD's need to be considered.
Put it in writing that you 'recommend' them or that should be fitted, cant be held accountable if powers that be decide to scrimp on the install cost and you'll have proof you need!