Amendment 2 new circuit SPD?

[catdog1121]

So I need to add a new circuit, I was going to do it to amendment 2.. Its a commercial property and will be adding a new circuit for a defibrillator cabinet and associated accessories (lights)... There is a decent enough 3 phase board in place, but there is no SPD.. Obviously if we add a new say socket circuit it has to have RCD protection even if there is no RCD protection in the existing board, this could require a new board. With SPD's now being mandatory (Apart from if customer refuses) what are peoples opinions.. There is no room to add an SPD in this three phase board so to add an SPD it would require a completely new board which would cost thousands and its out of the question...

The transformer is only a few houses away and all cables are underground and in the 60+ years the property has been there they have never had an issue with a transient voltage..

Is it ok to add a new circuit under amendment 2 without an SPD? (I am leaning towards yeah just add the circuit, having to add an SPD to an existing installation when it is not easily done is ridiculous)

 

[IAmSparkytus!]

How many spare ways are in the board?

 

[bigspark17]

Just note on the eic, recommend spd is insatlled customer currently does not want costs involved.

 

[catdog1121]

How many spare ways are in the board?

There are a few but its a 3 phase industrial sort of board so not the same as a domestic board, you cant fit them in..

 

[catdog1121]

Just note on the eic, recommend spd is insatlled customer currently does not want costs involved.

Yeah I think thats a good shout, my thinking was adding a new circuit for a few hundred quid to a defibrillator enclosure which the actual enclosure is worth not that much with just a small heater and light in it is not really going to make it any worse... But highlighted to me the problem as 99% of installations will not have an SPD... I guess the argument is you don't change a plastic board to metal to add a new circuit so why would you install an SPD, would you note a plastic consumer unit? I guess its not a big change from the last amendment and I installed new circuits without adding SPD's.. Obviously if I was changing the consumer unit then I would add an SPD but I guess common sense has to kick in at some point..

 

[brianmoooore]

Do a quick verbal quote to the customer for the works with a SPD and without, informing him that he can decline to have a SPD fitted.
Proceed, depending on the answer.

 

[loz2754]

An SPD doesn't have to go in the DB, it can be in an enclosure next to the DB.

 

[pc1966]

As @loz2754 says there are a few external box solutions for existing TPN boards. Usually the catch is you need a spare way to connect it to the busbars, either by "neutral links" as Hager offer, or using something like a 50A D-curve MCB for low inductance, or I think fuses (obviously) in the case of Ryefield board add-ons.

The cables to the SPD need to be short for low inductance, ideally no more than 0.25m (so loop is 0.5m max, though you can go to 0.5m for 1m loop but keep cables tight together for low loop area) so usually the box has to be mounted on the side of the existing DB.

 

[Alan-N]

So I need to add a new circuit, I was going to do it to amendment 2.. Its a commercial property and will be adding a new circuit for a defibrillator cabinet and associated accessories (lights)... There is a decent enough 3 phase board in place, but there is no SPD.. Obviously if we add a new say socket circuit it has to have RCD protection even if there is no RCD protection in the existing board, this could require a new board. With SPD's now being mandatory (Apart from if customer refuses) what are peoples opinions.. There is no room to add an SPD in this three phase board so to add an SPD it would require a completely new board which would cost thousands and its out of the question...

The transformer is only a few houses away and all cables are underground and in the 60+ years the property has been there they have never had an issue with a transient voltage..

Is it ok to add a new circuit under amendment 2 without an SPD? (I am leaning towards yeah just add the circuit, having to add an SPD to an existing installation when it is not easily done is ridiculous)

How's about a single phase sub board with its own type 2 SPD close to the protected equipment , < £100 populated

 

[westward10]

Don't install it to amendment 2 requirements.

 

[catdog1121]

How's about a single phase sub board with its own type 2 SPD close to the protected equipment , < £100 populated

That would comply, but its protecting a defibrillator cabinet, which is a small light and a heater, which would be less value than the £100.. There is also limited room to put an extra board... I think the easiest way is to just offer to replace the consumer unit or they can sign to say they dont want an SPD...

But it does raise a problem, where do you stop..
Do you have to install an SPD if doing maintenance work?
Do you have to install an SPD when adding to or altering an existing circuit?
Do you have to install an SPD when adding a new circuit?

Most customers may have room for a new circuit or two but not an SPD and new circuit, so are we to rip out new consumer units that are less than a year old? I understand they have made it simpler and its to stop the cowboys that were changing consumer units without fitting an SPD saying it wasnt needed... But by being so rigid they have caused a massive headache..

 

[pc1966]

Most customers may have room for a new circuit or two but not an SPD and new circuit, so are we to rip out new consumer units that are less than a year old?

Well if less than a year old it ought to have had SPD already!

You can get single module width SPD but usually they need some back-up MCB so no real space-saving over the double-width ones that are OK with the DNO's 100A max fuse. So yes, fitting a new circuit and SPD typically means 3 spare slots in the CU being used up.

Or its the external module, maybe some conduit coupler between enclosures so singles can be used between them and earth to chassis. Not ideal but off the shelf like:

40kA 2 Module Single Pole and Neutral Type 2+3 Surge Protector Metal Enclosure

Ideal for commercial applications

www.cef.co.uk

 

[pc1966]

If main fuse is 60A then some single width modules are rated for use without extra MCB, for example:

15kA 1 Module Single Pole and Neutral Type 2+3 Surge Protector

Combined Type 2+3 Surge Protection Device (SPD)

www.cef.co.uk

 

[timhoward]

But it does raise a problem, where do you stop..
Do you have to install an SPD if doing maintenance work?
Do you have to install an SPD when adding to or altering an existing circuit?
Do you have to install an SPD when adding a new circuit?

My usual pragmatic test is if doing an EICR afterwards would the change be worse than a C3.
But If installing a new circuit that circuit will comply with amendment 2.

For example - you get asked to add an outside light in a care home, and it has a Hager dual rcd board (type A for arguments sake). The lighting breakers are already 'busy' but there's a spare way. Do you:
a) add yet another branch to one of the lighting circuits
b) add a B6 to the spare way
c) say sorry you need a new metal CU with SPD and AFDDs, quote to fit outside light is £1200

 

[pc1966]

One reason here that SPD seems important here is this is for a defibrillator - you could argue that if it is damaged by a surge then it has direct implications for saving someone's life should it be needed.

But it could be local to the install via a small DIN rail box so power feed goes through this to SPD for low inductance (as no real loop of cable) or it could be adjacent to the main CU and linked via D-curve MCB or similar to protect all of the install.