will SPD protection now have to be added for an addition to an existing circuit

No not an alteration to an existing circuit but it will be needed for a new circuit... From NAPIT and IET...

catdog1121 said:

From NAPIT and IET...

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Other conclusions are available. Like mine.

timhoward said:

Other conclusions are available. Like mine

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Its IET making our jobs more harder.
Mr customer I need to take you to the bank before I install a SPD, first a map of
UK pointing to what area you need it and
Calculate if needed if you in a TT area
You need one, in urban area would you need it no.

The daft calculation has been removed in amendment 2, thankfully.

Most sparks I know adopt a mentality that generally if an installation would not attract more that a C3 during an EICR it is safe to extend. Any new work obviously has to meet new regs.
If fitting a new CU I'll fit one. A new circuit requiring one is not a given for me - I'll fit one if practicable. But it often isn't practicable especially if it would involve replacing an older 3 phase board due to lack of compatible units of same manufacturer.

The economics of this means that if quoting for a simple new circuit on a commercial job, no sparks who wants to rip out the entire board to add SPD protection will get the work!

Yes I agree has above, but to add a new circuit the requirement is to abide with regulations is to fit one or not fit one is non compliant, says the client don't want one. Sign this wayver. I'm talking domestic.

For non-residential properties that do not fit into these categories, a risk assessment must be carried out, a process that has also been simplified in the 18th edition, detailed in section 443.4 of the IET Wiring Regulations. Where this risk assessment is not conducted, the regulations require that surge protection is implemented.

buzzlightyear said:

For non-residential properties that do not fit into these categories, a risk assessment must be carried out, a process that has also been simplified in the 18th edition, detailed in section 443.4 of the IET Wiring Regulations. Where this risk assessment is not conducted, the regulations require that surge protection is implemented.

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As timhoward stated, this no longer applies.
The whole risk assessment idea and process has been removed in Amendment 2.

Also, there is no distinction made between residential and non residential properties anymore.

After listing the 3 situations where SPDs must be provided, the regulation (443.4.1) goes on to say:
"For all other cases, protection against transient overvoltages shall be provided unless the owner of the installation declares it is not required due to any loss or damage being tolerable and they accept the risk of damage to equipment and any consequential loss."

What it doesn't give any guidance on, is whether adding to a circuit, or adding a new circuit, would mean we would have to add one or more SPDs. This is where many of us would apply the previous guidance that was given, relating to whether an RCD would need to provided when altering or adding to an existing installation.

loz2754 said:

This is where many of us would apply the previous guidance that was given, relating to whether an RCD would need to provided when altering or adding to an existing installation.

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It's funny. There was an era (ok a long while ago!) where it was reasonably common to add an RCD in it's own enclosure if adding a shower circuit to a rewireable board. That felt as if it was achieving something and worth doing.
Maybe if I could get more excited about SPDs adding value I'd be more willing to fit them in their own enclosure. But thinking about it, there are some requirements regarding lengths of conductors for SPDs that I'd have to look up again, and last time I looked into it it wasn't trivial to achieve.

timhoward said:

It's funny. There was an era (ok a long while ago!) where it was reasonably common to add an RCD in it's own enclosure if adding a shower circuit to a rewireable board. That felt as if it was achieving something and worth doing.
Maybe if I could get more excited about SPDs adding value I'd be more willing to fit them in their own enclosure. But thinking about it, there are some requirements regarding lengths of conductors for SPDs that I'd have to look up again, and last time I looked into it it wasn't trivial to achieve.

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You can get from Wylex or Proteus an inline isolator and SPD, as its inline rather than parellel the length of conductors for SPD's is much easier to meet. I would say as its part of an isolator and not that big you could put it in the meter cupboard, so this might be a good solution...

It is made quite clear an SPD is required for a new circuit, there are solutions like above which will mean you dont have to replace the consumer unit, there is also a get out in that the customer can refuse... I checked with NAPIT and they were ok for me just to put on the EIC under departures of BS7671 that I have talked to the customer and they understand and accept the risk and have refused an SPD... Just give the customer the option, if they take it then great a little upsell, if they don't then just mark it as a departure.. I would say though if changing the consumer unit, I just would not give the customer a choice but I can see if say you wanted to add a circuit of a 16A mcb to provide a socket say under the stairs next to the consumer unit, adding an SPD could more than double the cost of the job, but put that decision onto the customer, I personally think that is why they added the get out clause of a customer refusing...

timhoward said:

Maybe if I could get more excited about SPDs adding value I'd be more willing to fit them in their own enclosure. But thinking about it, there are some requirements regarding lengths of conductors for SPDs that I'd have to look up again, and last time I looked into it it wasn't trivial to achieve.

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Regs state the total length which is the line length from the OCPD to SPD + CPC length from MET to SPD should preferably not exceed 0.5m but in no case exceed 1.0m
Virtually impossible to achieve under 0.5m in an external enclosure and very difficult to achieve under 1.0m
Even internal SPDs can be difficult to achieve within these limits for a 3 phase board

Eddy Currents said:

Regs state the total length which is the line length from the OCPD to SPD + CPC length from MET to SPD should preferably not exceed 0.5m but in no case exceed 1.0m
Virtually impossible to achieve under 0.5m in an external enclosure and very difficult to achieve under 1.0m
Even internal SPDs can be difficult to achieve within these limits for a 3 phase board

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My understanding was if you put it inline then the length is the cables inside the board... Check out David Savery video @ 18mins..


I could be wrong but that was my understanding..

Yes inline is fine because everything is in the enclosure
I was referring to retro fitting to an existing board as in BS7671 illustration



GSH also did a video on this scenario