Amd2 SPD on smoke alarms

bro8284 · Aug 19, 2022

Quick question guys, if adding mains smoke alarms in a rental / domestic property's will we also need to provide SPD now. cheers all

Lister1987 · Aug 19, 2022

bro8284 said:
Quick question guys, if adding mains smoke alarms in a rental / domestic property's will we also need to provide SPD now. cheers all

Amendment 2 isn't fully in force yet so no, however best practice would dictate yes as a smoke detector is a life safety system. When Amendment 2 is fully in force then yes SPDs will be required (we'll ignore that customer opt-out as they're unlikely to be competent to fully appreciate the risks of not having the SPD.

bro8284 · Aug 20, 2022

Lister1987 said:
Amendment 2 isn't fully in force yet so no, however best practice would dictate yes as a smoke detector is a life safety system. When Amendment 2 is fully in force then yes SPDs will be required (we'll ignore that customer opt-out as they're unlikely to be competent to fully appreciate the risks of not having the SPD.

That was my understanding as well, was asking as I was told that it doesn't cover domestic smoke alarms.
how we going to retro fit SPDs to old consumer units?

Dartlec · Aug 20, 2022

bro8284 said:
That was my understanding as well, was asking as I was told that it doesn't cover domestic smoke alarms.
how we going to retro fit SPDs to old consumer units?

There's nothing in theory stopping you from installing any 3rd party one like the surge protective device into any CU with a din rail. Because it doesn't sit on the busbar, the issues with compatibility don't arise - or at least that is their view.

You'd still need a compatible suitable MCB though.

You can get isolators with SPD built in, though they aren't cheap.

I think the confusion may be as to whether standard domestic smoke alarms are a "safety service" as defined in the book. I'd probably consider them to be based on the simple definition in the book

"Safety service. An electrical system for electrical equipment provided to protect or warn persons in the event of a hazard, or essential to their evacuation from a location."

However, following that line might mean that standard domestic smoke alarms should follow other regs about safety services, including having separate circuits, potential fire resistant cabling, etc. (Chapter 56)

So as usual, pick your interpretation until the guidance becomes clear and consistent (if ever)

timhoward · Aug 20, 2022

I'd be extremely surprised if I found myself refusing to fit smoke alarms. If it was truly impossible to squeeze an SPD into a full board then as a last resort there's the signed declaration route.

freddo · Aug 20, 2022

Dartlec said:
There's nothing in theory stopping you from installing any 3rd party one like the surge protective device into any CU with a din rail. Because it doesn't sit on the busbar, the issues with compatibility don't arise - or at least that is their view.

You'd still need a compatible suitable MCB though.

You can get isolators with SPD built in, though they aren't cheap.

I think the confusion may be as to whether standard domestic smoke alarms are a "safety service" as defined in the book. I'd probably consider them to be based on the simple definition in the book

"Safety service. An electrical system for electrical equipment provided to protect or warn persons in the event of a hazard, or essential to their evacuation from a location."

However, following that line might mean that standard domestic smoke alarms should follow other regs about safety services, including having separate circuits, potential fire resistant cabling, etc. (Chapter 56)

So as usual, pick your interpretation until the guidance becomes clear and consistent (if ever)

I'm not sure about that, the NIC inspector was not happy at all about the Surge Protective Devices Ltd surge module I had fitted in a separate 4 module Din enclosure made by Proteus, as they were different brands...

[ElectriciansForums.net] Amd2 SPD on smoke alarms

He would have laid an egg if he had seen the surge module I put on the rail beside the main switch in the last Hager 3ph board I fitted.

Dartlec · Aug 20, 2022

freddo said:
I'm not sure about that, the NIC inspector was not happy at all about the Surge Protective Devices Ltd surge module I had fitted in a separate 4 module Din enclosure made by Proteus, as they were different brands...
View attachment 100746
He would have laid an egg if he had seen the surge module I put on the rail beside the main switch in the last Hager 3ph board I fitted.

Interesting - was he saying that there were no circumstances in which their products could be used then, since they didn't until very recently make their own enclosures/MCBs?

Might be worth contacting Kirsty, their technical person, who is the one who told me that at an Elex a few years back. She is on some of the Regs committees I think, and might be able to provide something in writing to wave at any assessor in future....

I believe she was the one who always took the view that the main fuse was not an acceptable overcurrent protection and may have been partly responsible for companies like Hager changing their boards to include an MCB for SPD protection.

Although interestingly, in their guide they state that smoke alarms in a domestic property must be SPD protected, so I'd take that as fairly clear guidance from an industry source.

freddo · Aug 20, 2022

Dartlec said:
Interesting - was he saying that there were no circumstances in which their products could be used then, since they didn't until very recently make their own enclosures/MCBs?

I don't know, I wasn't there. The gaffer was the one who went around with the inspector. He couldn't see what the issue was, it's a Din module in an empty Din enclosure. Seems fine to me also, I've provided MCB protection, the correct size earth conductor and kept the cables as short as practicable.

Dartlec · Aug 20, 2022

freddo said:
I don't know, I wasn't there. The gaffer was the one who went around with the inspector. He couldn't see what the issue was, it's a Din module in an empty Din enclosure. Seems fine to me also, I've provided MCB protection, the correct size earth conductor and kept the cables as short as practicable.

Be interesting to ask him what Regulation he thinks it was breaching. If there is no other switchgear in the enclosure then it's clearly not a CU and type testing is surely irrelevant. DIN is a standard for a reason...

I hope the cup on top of it is not yet another manufacturer!

Lister1987 · Aug 21, 2022

bro8284 said:
That was my understanding as well, was asking as I was told that it doesn't cover domestic smoke alarms.
how we going to retro fit SPDs to old consumer units?

Domestic or not; fire detection (in which guise you want it) a life-safety system and should be protected.

As for old boards you'll probably find the Wylex REC2SPD (main switch and SPD in a self contained unit) used to afford type 2 protection of the installation. It could be argued that as it located "at source" that it should be a type 1 but you generally see those on LPS installations, See the BS EN 62305 series.

pc1966 · Aug 21, 2022

The type 1 SPD at source really only applies to LPS-equipped systems or ones with long overhead feed cables. Having a type 2 device is fine, so long as it is rated for the matching OCPD (if that is DNO fuse or separate MCB)

I suspect the NIC inspector is just following the "no mixed manufacture" aspect to the letter, which is kind of irrelevant for the outside DIN enclosure. But more importantly if the company making them certifies they are suitable for any CU subject to the matching MCB brand being used then they are taking responsibility for the overall design and you don't have to.

pc1966 · Aug 21, 2022

At the CEF 18th AM2 talk when mentioning SPD the guy said smoke alarms are not "safety systems" but as usual with no detail or justification for that point.

While there may be situations with a full CU where an overall SPD is not practical to fit for new alarms, in those cases you could just get the 10 year battery / wireless ones instead. If replacing existing alarm modules then you could argue it is not a new circuit so updated regs don't apply.

If it were a new hard-wired alarm I personally don't see how you could honestly say it is not for safety and so protection is optional.

UNG · Aug 21, 2022

pc1966 said:
At the CEF 18th AM2 talk when mentioning SPD the guy said smoke alarms are not "safety systems" but as usual with no detail or justification for that point.

Given that smoke alarms come under BS5839 part 6 why would they not be a "safety system" I think the guy really needs to clarify his comment as they are also a requirement of the building regs

Pretty Mouth · Aug 21, 2022

No SPD, no smoke alarms huh? Crazy.

nicebutdim · Aug 21, 2022

freddo said:
I don't know, I wasn't there. The gaffer was the one who went around with the inspector. He couldn't see what the issue was, it's a Din module in an empty Din enclosure. Seems fine to me also, I've provided MCB protection, the correct size earth conductor and kept the cables as short as practicable.

If an inspector raises an issue, but can't give a reason for doing so (along with supporting evidence), I'd be inclined to think they were in the wrong job.

Amd2 SPD on smoke alarms

bro8284

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Lister1987

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bro8284

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Dartlec

timhoward

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freddo

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Dartlec

freddo

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Dartlec

Lister1987

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pc1966

pc1966

UNG

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Pretty Mouth

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nicebutdim

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