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.

 

[timhoward]

One reason here that SPD seems important here is this is for a defibrillator -

I think, that surprisingly, the supply isn't in any way connected to the defibrillator, not even to a charger. I was surprised to find that one I did was simply a small heater to maintain an ambient temperature, presumably to extend battery life. The defibrillator just sits completely stand-alone in it's cosy little box. Lithium batteries really are very good at holding a charge....

I guess it still applies that if the the heater fails and the battery prematurely drains it has life changing possibilities, but it's one step further on the tenuous scale!

 

[pc1966]

I think, that surprisingly, the supply isn't in any way connected to the defibrillator, not even to a charger.

Ah - OK in that case I would not be so concerned!

EDIT: Maybe check what the manufacturer says just in case!

 

[catdog1121]

Ah - OK in that case I would not be so concerned!

EDIT: Maybe check what the manufacturer says just in case!

Manufacturer doesn't say any more really than install to BS7671 by a qualified electrician.. A few other bits about type of silicone etc but Tim is completely right all it is is a metal cabinet, with a small 200w heater that only comes on in very cold temperatures and a small LED light... They currently have no SPD, there has never been an issue with a transient voltage in its 60+ year history, the transformer is about 50yrds away and cable underground.. So the pre amendment 2 you would use the argument of I am only taking responsibility of what I am installing, I am not installing anything that would increase the value of the installation so you can argue an SPD is not needed based on the value.. However now its mandatory, I think its just about having the conversation with the customer and adding on the EIC, but customers don't seem to like this.. I have spoken to one of the two charities and explained and they don't care and are happy just to say its not needed, I think the other charity will also be ok also so it covers me..

 

[catdog1121]

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

This is a good way of looking at it, I could have come off an existing circuit, the only reason I didn't want to is political in that the defibrillator has been funded by one charity and the building owned by another, with one taking responsibility for the defibrillator, having it on its own circuit will mean nothing else can affect it and it wont affect anything else..

You might have type AC RCD's on that same board and it has an SPD, fitted not long ago, suddenly you need type A RCD's, although hopefully not so expensive.. with type A RCD's it should be easier to replace unless of course the manufacturer no longer makes them, in which case we could again be talking of a new board change just to add a circuit for an outside light..

I guess at some point common sense has to prevail, if you add a new circuit when you could extend an existing just because it is easier does that make it suddenly more dangerous... Its the part of the job I have always struggled with, how far do you go..

 

[pc1966]

I guess at some point common sense has to prevail, if you add a new circuit when you could extend an existing just because it is easier does that make it suddenly more dangerous... Its the part of the job I have always struggled with, how far do you go..

Very much so.

The usual consideration is never to make anything less safe by new work, but for some cases the regs would now expect type A RCD/RCBO for sockets, etc, and SPD generally. But unless the customer wants upgrades, or unless the new circuit is something where you would expect those to be important such as medical support, you have to draw a sensible line based on how cost-effective any changes to meet latest regs are.