SPD in commercial offices

[John-SJW]

Surge protection is now semi-mandatory in domestic (there are get out clauses).
Is SPD mandatory, or semi-mandatory, in commercial offices?

 

[pc1966]

We had put some effort in to protecting it against induced lightning surges, but never thought it would have survived a direct hit!

This was not really planned for, and the bureaucracy of trying to get the institute to fit some protection (and find the budget to do so) was a problem. The building itself was protected, but the antenna was now the highest point.

So we made up a makeshift LPS using stuff from local hardware shops, in between ice-creams and coffees, and hopefully it will be OK for the future:

 

[Strima]

What happens if their electronic equipment still goes bang in a lighting storm

In a commercial set up the installation should be set up in zones, each one designed to step down the surge current to a tolerable level at the equipment.

Same can be applied in domestic by using type 3 surge protected outlets.

 

[Strima]

We had put some effort in to protecting it against induced lightning surges, but never thought it would have survived a direct hit!

This was not really planned for, and the bureaucracy of trying to get the institute to fit some protection (and find the budget to do so) was a problem. The building itself was protected, but the antenna was now the highest point.

So we made up a makeshift LPS using stuff from local hardware shops, in between ice-creams and coffees, and hopefully it will be OK for the future:
View attachment 86202

Nice idea, I'm surprised they wouldn't just stump up for a couple of finials, they tend to be a lot cheaper than the damaged caused by a strike.

 

[pc1966]

Nice idea, I'm surprised they wouldn't just stump up for a couple of finials, they tend to be a lot cheaper than the damaged caused by a strike.

Ideally they would have had it done when the building LPS was updated at some point between our original installation and when we had to fix it. We saw the change in conductors, etc, but no thought about a point going above the antenna! There you go

Our make-shift one is not ideal, as it would provide weak protection from some directions as not high enough and no time / spare cash to put in a couple of them. But it was the first direct hit in over 20 years so not that common.

 

[i=p/u]

In a commercial set up the installation should be set up in zones, each one designed to step down the surge current to a tolerable level at the equipment.

View attachment 86206

Same can be applied in domestic by using type 3 surge protected outlets.

I thought if you covered the incommer the rest is just optional.

 

[John-SJW]

others are also vulnerable to damage though data lines (cable TV coax, phone line, etc) so would need separate protection.

That has always been my concern. OK SDP may save boiler pcb's and LED lights, but the expensive stuff is still vulnerable via data cables.

 

[John-SJW]

I thought if you covered the incommer the rest is just optional.

There is the incomer protection, and a second shield about 30 foot from the incomer. This may be anti-surge sockets on vulnerable equipment.

 

[John-SJW]

In a commercial set up the installation should be set up in zones, each one designed to step down the surge current to a tolerable level at the equipment.

I just looked at John Ward's Youtube vids on SPDs - has series of about five vids on SPDs, emphasising how essential it is. He goes into the zones aspect. Worth looking at.

 

[pc1966]

That has always been my concern. OK SDP may save boiler pcb's and LED lights, but the expensive stuff is still vulnerable via data cables.

It is less common now, as networking is mostly wireless or Ethernet (which is usually isolated and can take kV level spikes) within a building, and usually these days fibre between network switches in different buildings (or sometimes between floors of a building) which is to all intents and purposes immune to surges.

PoE Ethernet is more vulnerable due to the DC path for the power. Also commonly seen is RS232 / RS422 used for industrial plant, but they are often OK if not running hundred or more meters, or (more seriously) between buildings. Well-bonded cable try also helps to divert some of any induced surges away from the signal cables.

Again, not really domestic!

For domestic the risks for surges, outside of the AC power lines, are TV/satellite antennas/CCTV (really only if hit) and cable TV / telephone lines (as they run for long distances outside of the building).

 

[UNG]

So what the guidance is saying Johnboy, do a risk assessment of clients electronic equipment (cost)and ask them isit worth it or not.

They should sign it too.

Having seen a hospital take a substantial lightning strike with a repair bill of circa £500,000 and about 4 - 5 days disruption there was a full risk assessment done on the future risk of it happening again the results of which concluded that the cost (around £600,000) of installing the necessary protection across the site versus the strike risk was not a viable spend having had no documented strikes in the previous 40 - 50 years and a calculated future strike risk of 1 sometime in the next 44 to 400 years

Got caught out on my NIC assessment in 2019 for not fitting them on a commercial job.

No, just stearnly told us to do risk assessments in future on an individual basis (ie, for the cost and hassle of doing the assessment and getting approval from the client NOT to fit it its just easier to go ahead and fit surge and charge a bit more for the job)

Sounds like the NIC trying to make a point and help the manufacturers sell more, I'm surprised the NIC are not insisting on professional indemnity for contractors in case they fit the wrong type of SPD

What happens if their electronic equipment still goes bang in a lighting storm

Anyone for efficacy insurance if the SPD fails to operate under surge / strike conditions

Don't know about cable TV, but traditional phone lines always had SPD at the master socket and there are standards for the sort of spikes that telecoms stuff should handle.

Though I suspect that has gone from newer systems. Probably BT, etc, treat the modems as disposable - they often don't update the crap software anyway!

I've seen a lot of surge arrestors fitted on intruder alarm comms kit where the installer didn't bother to connect them to a suitable earth so it made them a bit useless

Ideally they would have had it done when the building LPS was updated at some point between our original installation and when we had to fix it. We saw the change in conductors, etc, but no thought about a point going above the antenna! There you go

Our make-shift one is not ideal, as it would provide weak protection from some directions as not high enough and no time / spare cash to put in a couple of them. But it was the first direct hit in over 20 years so not that common.

I've worked on a number of sites with rooftop comms kit and while installing comms kit I got into the habit of doing a quick test on the LPS down lead after we had some interference problems on one site where all the comms cables going to a number of buildings were earthing the LPS at the indoor units because the LPS down lead connection to the earth rod was broken and this was on an LPS that had been tested and certified some 10 months earlier the customer was adamant that it was ok and waved the certificate at me so I got a spade out and exposed the corroded LPS earth connections and then had to more or less drag him out of his office across the site to show him the problem that we had found

I just looked at John Ward's Youtube vids on SPDs - has series of about five vids on SPDs, emphasising how essential it is. He goes into the zones aspect. Worth looking at.

Based on what risk assessment and likely hood of it actually happening

When you look at the cost of an SPD I suppose it could be classed as an insurance policy that could sit there for many years and may never ever be needed so how do you justify the cost to the customer. As installations are altered and modified should the risk assessment be revisited to confirm that the type of SPD's installed are suitable for what may be a changed risk within the installation or whether the changes mean an SPD should be installed, which is something that no doubt will be addressed in future guidance

The combined industry experience of this forum probably runs to many hundreds if not thousands of years so the question is how many jobs have members been to where SPD's may have or would have prevented equipment damage and then would the cost of installing SPD's v's the replacement / repair cost of the equipment and disruption caused made it a cost effective decision to install SPD's
Personally in all the years I have worked in the industry I have only seen less than a handful of incidents that may have benefited from an SPD being installed so why is the push now to suggest that sites are at a much greater risk

 

[Strima]

I thought if you covered the incommer the rest is just optional.

An SPD will not fully stop a surge, it steps it down to a more manageable level.

I've lifted this from the Hager SPD guide:

• Type 1 - SPD which can discharge partial lightning current with a typical waveform 10/350 μs. Usually employs spark gap technology.

• Type 2 - SPD which can prevent the spread of overvoltages in the electrical installations and protects equipment connected to it. It usually employs metal oxide varistor (MOV) technology and is characterized by an 8/20 μs current wave.

• Type 3 – These SPDs have a low discharge capacity. They must therefore only be installed as a supplement to Type 2 SPD and in the vicinity of sensitive loads. Type 3 SPD’s are characterised by a combination of voltage waves (1.2/50 μs) and current waves (8/20 μs).

In a nutshell, Type 1/2 at the incomer to protect the installation and Type 3 to protect the current using equipment.

 

[Strima]

The combined industry experience of this forum probably runs to many hundreds if not thousands of years so the question is how many jobs have members been to where SPD's may have or would have prevented equipment damage and then would the cost of installing SPD's v's the replacement / repair cost of the equipment and disruption caused made it a cost effective decision to install SPD's

Had one customer, of a previous employer, who would call us out at least once a year to replace a faulty rectifier module on one of their sites just north of Carlisle. After the third incident I decided to do a little research and the site alarm would trigger a rectifier fail everytime there was an electrical storm in the area.

We recommended fitting SPDs, the site has it's own LP system but it was installed long before SPDs were required. The customer declined due to cost, but each rectifier module was just over £2k to replace, but on a different budget...

This was a dark fibre switching site for a major fibre network supplier so a critical location, they risk potentially millions in lost revenue per hour if the site goes down but penny pinch on infrastructure...

 

[pc1966]

When you look at the cost of an SPD I suppose it could be classed as an insurance policy that could sit there for many years and may never ever be needed so how do you justify the cost to the customer.

To some extent this is how I see it. These days many domestic CU have them already fitted, or they are around £50 more, so on a board change it is typically under 10% of the cost and could well save that in years to come.

However, I have always been a bit paranoid about circuit protection as over the years we put in stuff in locations that suffer far more than the UK in this respect. For example, we had stuff in Malaysia where you got major lightning storms practically every 2nd afternoon! Even as I first saw the country on leaving the airport I noticed how big and deep the road side gutters were, and within a couple hours saw why!

For that system we had to retrofit more protection, and so from then on we assumed the worst and designed it in.

Personally in all the years I have worked in the industry I have only seen less than a handful of incidents that may have benefited from an SPD being installed so why is the push now to suggest that sites are at a much greater risk

I think the change is now we are seeing far more easily damaged stuff being used in homes. LED lighting, an array of expensive electronics goods, and most white-goods are now controlled by complex solid-state systems. Also they are getting cheaper and nastier by design as they get "value engineered" to save a couple of pence here and there.

Yes, at least we have the EMC directive singe 1996 that finally mandated some degree of immunity as a requirement, but a lot of cheaper stuff I would be fails to meet it and no one does anything

 

[pc1966]

I've seen a lot of surge arrestors fitted on intruder alarm comms kit where the installer didn't bother to connect them to a suitable earth so it made them a bit useless

I've worked on a number of sites with rooftop comms kit and while installing comms kit I got into the habit of doing a quick test on the LPS down lead

Indeed! This should be the FIRST point when looking to install!

Without a good low impedance (dominated by inductance) earth the SPD are often ineffective, to the point of potentially being useless (or even dangerous, if internal metalwork becomes many kV on a surge).

 

[i=p/u]

The insurance companies are going to have to suck it up and obviously charge. You cant tell people you need this to save your electronic equipment and it doesn't work.

I'd say are own personal indemnity insurance will be attacked. They be Waiting for lighting in area and false claims to arise..