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?

 

[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..

 

[John-SJW]

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



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


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

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 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

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

At 12 mins John Ward explains why these day SPD is important. Dave Savery on one of his vids fitted SDP under an assumption spikes were causing expensive LED lamps to fail too frequently. It was fitted then no problems. How many expensive pcb boards in boilers would have been saved if SDP was fitted? Not to ention being cold and no hot water. mmmm Expensive components may have failed, yet we do we attribute the failure to a spike!

 

[John-SJW]

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

Lightening can strike the earth then affect underground cables quite frequently giving spikes. There does not need to be a full building strike or a direct strike onto a cable. These frequent strikes can be arrested by the SPDs.

 

[John-SJW]

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

Between 1942 and 1977, Sullivan was hit by lightning on seven occasions and survived all of them.

Roy Sullivan - Wikipedia

en.wikipedia.org

 

[i=p/u]

Hes in america and a storm chaser.

 

[UNG]

At 12 mins John Ward explains why these day SPD is important. Dave Savery on one of his vids fitted SDP under an assumption spikes were causing expensive LED lamps to fail too frequently. It was fitted then no problems.

A really scientific approach to solve a problem then, so lamps failed then they didn't after the SPD was fitted so could it have been..............................a bad batch of lamps!
It is one of those situations were a power quality analyser with a before and after analysis may have given it a bit more credibility

How many expensive pcb boards in boilers would have been saved if SDP was fitted? Not to ention being cold and no hot water. mmmm Expensive components may have failed, yet we do we attribute the failure to a spike!

Most of the failed boiler PCB's I've seen are down to crap soldering during manufacture causing high resistance joints that overheat and burn the board

Between 1942 and 1977, Sullivan was hit by lightning on seven occasions and survived all of them.

Roy Sullivan - Wikipedia

en.wikipedia.org

Did he have an SPD fitted??

 

[John-SJW]

Did he have an SPD fitted??

Yes. The lightning never got him. He committed suicide.

 

[John-SJW]

A really scientific approach to solve a problem then, so lamps failed then they didn't after the SPD was fitted so could it have been..............................a bad batch of lamps!

That approach worked. I am not sure if he said he contacted the local weather people to see if there were many lightning strikes about.

Interesting comment on John Ward's vid......

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Thanks John, this is a great video, really helpful to explain the use of and requirement for surge protection. Very few people really realise the true extent & cost of damage caused by over voltage issues, one reason for that is that the UK insurance industry is very tight lipped about these things. In Germany this is not the case the insurance industry makes information freely available and they suggest that from all claims of "electrical or electronic damage" over voltage / surge issues are responsible for 31% of the claims. That is a huge figure, for anyone reading this and thinking "he's an idiot, I've never seen anything like that level of damage" ....well how do you know? Over voltage damage is not always immediate and spectacular, there may not be a huge bang and plumes of black smoke.

You can have several incidents over a few weeks and it would lead to wear and tear, then one day flick a switch on and the equipment doesn't work. Do you immediately think "oh that must be wear and tear fro over voltage events" of course you don't. You think "oh that's broken, more money to replace it /repair it". SPD's offer longer life spans for equipment, increased levels of availability, reduction in down time and less maintenance. They are like "electrical life assurance for equipment".