Surge Protection for the Modern Home

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20 years ago, we would have classified a domestic home as a simple electrical installation but with the massive jump in available technology, I’m not sure simple electrical installations exist anymore. This causes complications in all areas of designing an electrical installation, and the topic of surge protection devices is no different.

For a domestic installation the advice has always been quite simple. If it is a normal sized home, with one consumer unit, you need one SPD and that will provide you sufficient protection. There has been a bit of confusion around the application of the 10-meter rule, but this is largely for much larger, more complex installations, with external lightning protection systems are installed and we are considering the requirements of BS EN 62305. Not your usual terrace home.

The choice of SPD, again, was quite simple. Most domestic installations would need a type 2 SPD installed in the consumer unit. The only time this would change, would be in the event that the house is directly fed via an overhead supply, where a type 1,2&3 combined SPD should be installed between the meter and the consumer unit, to provide protection in the event of a direct lightning strike to the supply cable feeding the property.

So, you would know quite quickly what type you needed, once you knew the earthing arrangement, a quick call to your friendly SPD experts and you would have a part number, easy peasy.

Now, we have a few more complications.

Does the installation have an EV charger? It is recommended, and required by some manufacturers of chargers, to have an SPD installed to provide protection to the valuable sensitive electrical equipment. This is even more relevant if the charger being installed has a loss of neutral device. This device is a safety control, which is there to disconnect the charger in the event of a loss of neutral, but the sensitive components within this device can be degraded, overtime, by repetitive switching surges, such as those produced by an inverter – like an EV charger. In this case, it would be recommended to install an SPD local to the car charger, this would be a type 2 SPD, and could be installed within the garage unit, supplying the charger.

Does the installation have a PV system? It is a requirement in BS7671, that if the installation requires an SPD on the AC side, it is also required on the DC side of a solar PV system. This device is different to the devices you would install on the AC installation and is specifically designed for the use on the DC side of the PV system. As it’s very rare to find a domestic installation with an external lightning protection system, we can pretty much say for a domestic PV installation, it would be a type 2 SPD. The additional consideration for the selection of a PV SPD is the operating capacity of the inverter. Generally, we would be looking at a 600V/1000V system, usually a 600V for most domestic installations. So, for our devices, this would be the SPDPV600, and this would need to be installed one per string, in parallel with the inverter.

We even have to think about the heating system, now, it is no longer down to the heating engineer! The growth in popularity of ground source and air source heat pumps have introduced sensitive control panels, which are extremely expensive to replace, along with downtime of a heating system, which no homeowner will want. If this equipment is installed, it would be recommended to look at an SPD local to the control panel or the pump, depending on the installation, to provide suitable overvoltage protection.

We have an ever-expanding technological growth right now, in the domestic market. Consumers are concerned with reducing energy usage alongside producing energy, with battery storage & prosumer installations on the rise. We can even see an emerging market for domestic voltage optimisation, aimed at reducing energy usage, technology that previously we have only seen applied in large industrial settings.

All of this is easy to navigate, with a bit of guidance, but it is definitely worth thinking about, the next time you look at what you think is just a simple job, there are not many of those left!

CPD & It’s Continuing Importance

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The industry view of Continuing Professional Development (CPD) really shifted during the pandemic. Electricians having more free time on their hands, turned to upskilling themselves, but I think this has really highlighted how little training and further learning was being undertaken by previously. Competence scheme providers have long been advocates of CPD, along with industry groups, such as the E5 group regularly encouraging contractors to ‘level up’ by increasing their knowledge, but are we slowly heading back to where we were?

As a manufacturer in quite a specialised area, I have always seen CPD as an extremely important area of the industry. With new technology emerging so fast, electricians run the risk of being left behind if regular CPD is not completed.

Due to the pressures of working as an electrician, CPD gets put on the back burner, especially for small contracting companies and sole traders, who have to lose income to complete valuable training. I saw so many people on social media who made massive accomplishments in learning and training during lockdown, that during a normal period, would have been impossible.

The availability and suitability of free CPD opportunities is something that as an industry we need to address moving forwards. From my point of view, I feel that manufacturers have an obligation to offer CPD opportunities to anybody that wants to learn. There was been a massive increase in the CPD offered during the pandemic but this does seem to have decreased unfortunately or put behind a pay wall.

Working for a company that specialises in surge protection, my career has always has always centred around training and CPD. Before the 18th edition, surge devices were not widely used within most sectors of the industry, so my job entailed lots of educational talks, seminars, CPD events, appearing on industry podcasts and writing magazine articles. When lockdown happened and it put a pause on our in-person events, I realised that I could carry on delivering quality training on a virtual basis and that led to launching the free SPD Training Academy.

I was absolutely overwhelmed with the response and one live session a week quickly became a daily event! I have now trained thousands of electricians, specifiers, electrical consultants, lecturers and apprentices throughout every level of the electrical industry, all for free, without leaving my office. I have had some lovely feedback and my sessions have been met with such gratitude, that I think it has really highlighted to me the lack of free, understandable, CPD being offered throughout the industry.

We wanted to ensure that people could still take part in training, as the world opened back up, so we recorded 10 modules, all 10-15 minutes long, which breaks down all different aspects of SPDs. It covered everything from the basics of what an SPD does and how it works, through to installation and specific requirements, such as for solar PV. It is fully online, so you can log in and do the training session in your own time then contact me directly with any questions.

I would like to see more manufacturers offering CPD as a way to help the industry, rather than a sales exercise. I have given training to contractors and consultants that have openly told me they don’t use my company’s products. What is important to me, is that the education is there to ensure that the correct devices are selected and installed, that people understand the wiring regulations regarding surge devices, understand why they are being installed and they are being installed correctly – not what brand of SPD is being used.

I hope, going forward, we don’t forget the value of CPD and its importance to ensure that we, as an industry, stay relevant and up to date.

Surge Protection & Solar PV Installations

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The number of solar PV installations is on the rise, with consumers wanting to reduce energy prices and the industry moving towards more of a prosumer approach to energy use. One of the aspects of PV system design, that is often overlooked, is surge protection.

BS7671:2018 regulation 712.443.101 states that where protection against transient overvoltage is required by section 443, such protection shall also be applied to the DC side of the PV installation. So, if the solar installation as on the roof of a building where the regulations in section 443 require SPD’s to be installed, SPDs would now also need to be installed on the DC side of the installation to protect the inverter.

Some inverters state that they include overvoltage protection.  For an incorporated SPD to fulfil the requirements of the wiring regulations, the manufacturer must specify that it is installed on the DC side of the inverter, as this ensures that it is providing protection on the correct side of the inverter. There are quite a few inverters on the market which say they have overvoltage protection included, when in actual fact, it is only providing protection on the AC side of the system. It must also state the type of SPD, the reason it is important for the type of SPD to be mentioned is that once a device is specified as a type it must conform to the product standard BS EN 61643-31 as some manufacturers incorporate individual varistors, which are not considered to be a complete surge protection device.

Another consideration is that the inverter will only ever include a Type 2 surge protection device, so if the building has an external lightning protection system, then the installation will always require the use of external Type 1 SPDs to conform to BS EN 62305.

When a PV system is installed on a building with an external lightning protection system (LPS) the PV system should be separated from all parts of the LPS in accordance with BS EN 62305-3, this is referred to as the separation distance. This is the distance that must be adhered too between the LPS and any metal work to ensure that no dangerous arcing can occur. If the separation distance is not met, then the metal work must be bonded to the LPS, therefore becoming part of the lightning protection system.  More information on separation distances can be found in BS EN 62305, but it is important to note that the separation distance depends on different parts of the lightning protection risk assessment carried out for each individual building, and therefore will be included in the LPS paperwork, if available. This calculation should only be carried out by someone with experience in the lightning protection field. If the separation distance is not met and therefore the PV system has become part of the LPS then the SPD required will need to be a Type 1, as mentioned above, this will always be external from the inverter.

From experience, there are not many installations that correctly conform to these separation distances, so as a general rule, if the building has an LPS a Type 1 SPD should be installed on the DC side of the installation. For all other PV systems, a Type 2 SPD will provide adequate protection.

Although the SPDs are still defined as Type 1 and Type 2 devices, they are different to the SPDs we see used on the AC electrical systems and only SPDs that are designed for the specific use on the DC side of a solar PV installation should be used. This is due to the continual loading and higher voltages of PV systems. The devices designed for the use on the DC side of PV systems are clearly marked with the PV symbol, as per the requirements in BS EN 61643-31. Also, they obviously look slightly different, with the live and neutral terminals being replaced by a positive and negative terminal.

Selection of a PV SPD is quite simple. From the above, you should know what type of SPD you need. The only other information needed is the operating capacity of the inverter, which is usually 600V or 1000V. There are some specialist systems which are different, and there are devices available for those too, but for simplicity we will stick with the 600V & 1000V options. That gives four options of devices.

Now we have the correct device selected, we can move on to installation. As with our AC SPDs, our DC SPDs are installed in parallel with the string, usually a DC isolator would be used. DC SPDs should be installed one per string to provide protection, although in some situations, it may be possible to protect multiple strings with one SPD, depending on the installation design.

Electric Vehicles and Surge Protection

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By their very nature, EV chargers are both sensitive (limited impulse withstand capacity) and exposed to overvoltage. In fact, quite a few EV charger manufacturers will specify that an SPD should be installable or mention surge protection in the warranty details.

So where is the risk of damage?

EV chargers are installed outside; therefore, they are liable to experience the effects of nearby lightning strikes. There is an increased risk of the charger being damaged from the effects of lightning, if the installation has an external lighting protection system, or if the EV unit is supplied directly from the main incomer of a building fed by an overhead supply.

Damage could also come from the installation, in the form of switching overvoltages. Overvoltages could also come from the supply network, or be created by equipment within the electrical installation. This form of repetitive overvoltage could damage the sensitive components used in EV chargers.

Also, EV chargers can cause issues with the electrical installation. We have to consider that any cable that enters an installation can bring with it the risk of overvoltage, as mentioned previously, the effects of nearby lightning strikes, are a risk to the electrical installation, along with the EV charger unit. Inverter technology can produce overvoltages, which can potentially cause damage to sensitive equipment inside the installation.

So, our risks are:

  • Damage to the EV charger
  • Damage to the car
  • Damage to the electrical installation

Using section 443 in BS 7671:2018 amendment 2 we can consider the requirements of SPD’s. Just as a reminder, 443.4 states that:

Protection against overvoltages shall be provided where the consequences caused by over voltage could:

  1. result in serious injury to, or loss of, human life
  2. result in damage to a safety service (deleted by corrigendum May 2023)
  • result in significant financial or data loss

For all other cases an SPD shall be installed, unless the owner accepts the risk of damage.

The obvious starting place would be to consider the result in significant financial loss. EV technology is expensive to install, not just from a charger perspective but also for the car itself. We also have to consider the implications involved, if a charger was damaged and the user could not charge their vehicle.

There is also the risk to life implication that must be considered if loss of neutral technology is used. These devices are designed for use in installations where there is a PME earthing arrangement. When the PEN conductor is broken, the neutral voltage can rise with respect to true earth and the normal protective earth forms the return path for any current that could flow. This could cause a car plugged in to charge to become live, if contact was then made with the car there is a danger of electric shock. Most EV charger units now rely on this technology to disconnect the supply to the charger in the event of a fault.  If this technology is damaged however, such as by the effects of lightning or some other form of overvoltage, this disconnection will not happen. Meaning that in the event of a fault, an electric shock could occur.

If the installation has an external lightning protection system, we also have to consider the requirements in BS EN 62305. Any cable that crosses the lightning protection zone 0 to zone 1, requires a type 1 SPD to be installed, to protect the installation. If, therefore, you are installing an EV charger (or bank of EV chargers) on an installation with an external lightning protection system, the DB supplying the external circuit will require a type 1 SPD to protect the installation, and another type 1 device in the feeder pillar supplying the chargers to protect the chargers from lightning effects on the external cable.

With all EV installations, I would recommend an SPD, this is to protect the car charger, itself, along with the installation.

I hope this article has provided some guidance on the requirements from BS 7671:2018 amendment 2, if you have any further questions, or would like to participate in any of our free CPD sessions, please do not hesitate to get in touch.

Kirsty Johnson MIET

kirsty@surgedevices.co.uk

www.surgedevices.co.uk

01484 851 747

Should you test an SPD?

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With the increase in the application of surge protection devices to our electrical installations, we have seen an increase in testers being marketed as able to test an SPD.

This raises the question: Should we test SPDs?

The simple answer is no. Any test on an SPD will involve passing voltage though the device to ensure activation, this passing of the voltage will degrade the components within the SPD and therefore shorten the lifespan of the device. The SPD does not know the difference between voltage for test purposes and a surge which it is designed to remove from circuits.

SPDs have certificates of conformity to demonstrate that they are built to the relevant part of the BS EN 61643 series for that type of device. If the SPD is unable to provide protection, weather this is due to a fault within the device itself or that the device has come to the end of its life span, the indication on the device will show the failure.

Realistically, any simple tester that can apply voltage will demonstrate that the SPD will activate when required, just because you can do something, does not necessarily mean that you should.

If you require any assistance on surge protection, please feel free to contact me.

Kirsty Johnson MIET

Site Survey’s for Surge Protection

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As a company we have always offered site surveys for complex electrical installations, but during the pandemic, when we couldn’t travel, we also found that we can offer an excellent service remotely, which helps us get to site faster. There as some situations, where an in-person site visit is still recommended, but for the majority of sites, a remote site visit is preferable.

  1. What type of situation would you recommend a company requests a site visit?

 

We can specify the surge protection required for the majority of sites with a simple phone call to our office, but sometimes site visits are recommended for complex electrical installations, usually where there will be multiple incomers, external lightning protection systems and installations where surge protection is being installed due to large amounts of previous damage.

 

  1. Where would you suggest using an on-site visit, rather than a remote assessment?

 

In person on-site visits would be recommended for very complex electrical installations, installations where internet connectivity may be an issue and also installations where data protection and safe guarding mean that video calling is prohibited.

 

  1. How does a site visit generally work?

 

Before arranging the appointment, whether in person or online, we will usually have an in-depth conversation with the electrician in charge, many sites we can specify without the need to actually come to site, so this is where we will usually establish the need for the site visit. Once the need has been established, we will work with the electrician to work out which method of survey will be the most beneficial.

 

Once on site, either in person or remotely, we will usually start the survey at the main incomer (or each main incomer individually, if it is a very large site) and assess the needs, while having discussions with the electrician regarding installation and location of devices. We will then proceed to look at sub distribution boards and finally specific equipment which may require individual protection. At this point we will have a discussion with the electrician to assess whether there are any additional things to consider for the installation, such as PV systems and EV chargers.

 

At the end of the visit, we will go away and produce a report with our findings and recommendations according to the latest regulations, which will be sent to the electrician as soon as possible.

 

 

  1. What tends to be the most common misunderstandings around the requirements of surge protection that you generally come across?

 

One of the most common misunderstandings is that surge protection can be installed at the main incomer to protect the entire installation, surge protection needs to be considered for the main incomer and then every distribution board over 10 meters from the incomer, to provide protection for the installation. If there is an external lightning protection system installed, this is even more important. This will mean that every cable that enters or leaves the installation requires a type 1 SPD installed to meet the requirements outlines in BS EN 62305.

 

  1. Are you finding there are common themes with the types of recommendations you are making (more surge protection required, for example)

 

I am finding that more thought is now being given to the protection of specific equipment pieces, such as fire alarms and data racks within installations. This is usually the sensitive equipment that is vital to the installation, in terms of safety and reliability.

 

 

  1. Give us an example of a recent/interesting visit you’ve made and how that went for all parties

 

My only in person site survey in recent times, was an extremely complex site, with multiple incomers, back up generators and external lightning protection systems.

The client had got in contact with us due to issues with an BMS panel that had been upgraded, due to the majority of the electrical services being underground, a remote session was not possible.

On visiting the site, it was quickly established that there were multiple external lightning protection systems, without adequate surge protection installed, but this was not what was causing the issues with the BMS systems.

On further discussions with the site engineers, I was told about the generator testing that happens regularly. It was my opinion that this was what was causing the damage to the BMS controls. It was discovered that the BMS systems had recently been upgraded, there were historically no issues with the old panels, but the generator testing did align with the damage that was seen on the newer panels.

As the newer controls were more sensitive, the same overvoltage was now causing damage. A plan for the rollout of site wide surge protection was then put in to place to help overcome any future issues with upgrading technology.

If you have any further questions, or would like to discuss a potential site visit, please do not hesitate to get in touch.

Kirsty Johnson MIET

kirsty@surgedevices.co.uk

www.surgedevices.co.uk

01484 851 747

Surge Protection – FAQ’s

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Since the release of the 18th edition there has been an increase in the use of surge protection devices, this is only growing with the additional requirements in amendment 2. As always, with a new subject matter, there is a few frequently asked questions that hopefully I have covered below:

Question Answer
 

Will an SPD need replacing after every surge?

 

 No, an SPD is deigned to take multiple surges and internally reset after each over voltage. An SPD will only need changing at the end of its life (the warranty is manufacturer dependent) and this will be shown in the status indication on the front of the unit.
When do I need to use a type 1? With the increase in availability of consumer units with the SPD already installed, it is becoming more of a consideration as to if this is the correct device. A type 1 will be needed in a domestic installation, if the property is supplied via an overhead cable. Outside of domestic installations, a type 1 device will also be required if the structure has an external lightning protection system.
Why do some manufacturers need an MCB before the SPD? According to BS7671, all SPDs shall be protected from overcurrent, this can be done with an MCB or an internal fuse. As a company we specify the use of MCBs with all of our devices. The MCB will provide a back up in case of a failure within the SPD, while also protecting the cable and giving a point of isolation for the SPD.
How do I measure the cable lengths to ensure I meet the BS7671 requirements? If the SPD is installed within the consumer unit, cable lengths will automatically be suitable. When installing outside of a consumer unit, you must ensure that all cables combined are less than 1M in length. Length A will be from where you take your live supply to the MCB (this is 0 if the MCB is on the busbar), Length B is from the MCB to the SPD and Length C is from the SPD to the closest earth point (not the MET). For a more detailed explanation of this, please look at our installation guide available on our website.
Will an SPD installed in the consumer unit protect the whole domestic property? An SPD in the consumer unit will massively reduce the risk of any internal damage within the electrical installation from overvoltage coming from the mains supply. Obviously, there are other routes of entry in to the electrical system, via aerials, telephone lines or any external cables, but there is no requirement in BS7671 to protect these routes.
Do I need to install type 3 devices in a domestic installation? There is no requirement to use type 3 devices. The type 2 on the consumer unit provides an enhanced level of voltage protection for the installation. Type 3 devices would only be used in specific specialist circumstances.

 

I hope that has answered some of your questions, if you have any questions I haven’t covered, or would like any specific help with an project or installation, please feel free to contact me directly at  kirsty@surgedevices.co.uk and for more information, please visit our website: www.surgedevices.co.uk

SPD Training Academy

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I am proud to announce that the team at Surge Protection Devices Ltd are launching an SPD Training Academy.

What is the SPD Training Academy?

The SPD Training Academy is a new addition to our website offering. We aim to provide attendees with up to date information regarding surge protection through our range of webinar sessions.

All of our webinars are completely free and we are CPD certified, so every attendee will receive a CPD certificate. All webinars are given by Kirsty Johnson, our technical sales director. Kirsty sits on the JPEL panel to assist with the wiring regulations, so is well placed to give training on Surge Protection to the latest regulations.

 

 

 

 

 

 

 

What topics are covered in the webinars?

SPD Ltd currently has the following courses available for immediate sign up:

Basics and the 18th Edition: This session is aimed at electrical contractors who may have limited or no experience with surge protection to give a basic understanding of what surge protection is and why we use it, through to how it works and where it needs to be installed. We will then cover the 18th edition guidance to finish off the session.

Apprentice: Introduction to SPD’s: This session is an apprentice only session where we will cover the fundamentals of surge protection to prepare apprentices to do the full basics and the 18th edition webinar (above).

Focus Training: Surge Protection Devices: These sessions are bespoke sessions for Focus Training learners, please contact your lecturer for further information.

 

 

 

 

Lightning and Surge protection in Commercial and Industrial installations…

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Lightning and Surge protection in commercial and industrial installations

 

 

 

 

 

 

 

 

Following on from my previous post on 21st November about Lightning protection in domestic installations we move on today to discuss lightning and surge protection in commercial and industrial installations.

BS7671 states that Surge Protection Devices (SPD’s) must be installed where the consequence of an over-voltage could result in an interruption of commercial and industrial activity, which in most commercial / industrial installations will be the majority of distribution boards.

When considering which device to install, we need to look at where on the electrical supply you are working. If you are working on a main incoming panel, you will need to assess whether the building needs a combined lightning and surge device (Type 1+2+3) to protect against direct lightning strikes. As discussed in the previous article, only buildings which are either fed by an overhead power line or have an external Lightning Protection System (LPS) will need a Type 1+2+3 device, otherwise a Type 2 device is sufficient. If you are working on a sub distribution board that doesn’t feed any external circuits, the device you will need is a Type 2, which will protect against any transient over-voltages.

If you were looking at protecting a whole commercial or industrial installation, rather than just the board you are working on, firstly a device will need to be installed on the main incomer, then any sub distribution boards more than 10 meters away will need their own protection. Unfortunately, surge protection has a limited range of protection, which is limited after a 10 meter radius, and as surges are most often caused inside the electrical installation rather than transmitted from the main incomer, it is important to ensure that the devices are installed as close to the equipment you wish to protect as possible.

If you want to discuss this any further please call our specialist surge team on 01484 851 747.

The Importance of CPD Post-Pandemic

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The industry view of Continuing Professional Development (CPD) has really shifted during the pandemic. Electricians having more free time on their hands, turned to upskilling themselves, but I think this has really highlighted how little training and further learning was being undertaken by the industry pre-COVID. Competence scheme providers have long been advocates of CPD, along with industry groups, such as the E5 group regularly encouraging contractors to ‘level up’ by increasing their knowledge.

As a manufacturer in quite a specialised area, I have always seen CPD as an extremely important area of the industry. With new technology emerging so fast, electricians run the risk of being left behind if regular CPD is not completed.

Working for a company that specialises in surge protection, my career has always has always centred around training and CPD. Before the 18th edition, surge devices were not widely used within most sectors of the industry, so my job entailed lots of educational talks, seminars, CPD events, appearing on industry podcasts and writing magazine articles. In fact, pre pandemic, I was driving up to 1000 miles a week covering the UK and Ireland covering these events! So, in March of last year, when I was grounded, like most people, for the first few days I didn’t know what to do with myself. After discussions with colleagues and friends, I realised that I could carry on delivering quality training on a virtual basis and that led to launching the SPD Training Academy.

I was absolutely overwhelmed with the response and one live session a week quickly became a daily event! I have now trained thousands of electricians, specifiers, electrical consultants, lecturers and apprentices throughout every level of the electrical industry, all for free, without leaving the office. I have had some lovely feedback and my sessions have been met with such gratitude, that I think it has really highlighted to me the lack of free, understandable, CPD being offered throughout the industry.

The pandemic and the following lockdowns gave people more time. It’s crazy now to think of all of the important training and CPD on vital issues, that was missed pre-COVID due to the pressures of working as an electrician within the electrical industry. CPD gets put on the back burner, especially for small contracting companies and sole traders, who have to lose income to complete valuable training. I have seen so many people on social media who have made massive accomplishments in learning and training during lockdown, that during a normal period, would have been impossible.

The availability and suitability of free CPD opportunities is something that as an industry we need to address moving forwards. From my point of view, I feel that manufacturers have an obligation to offer CPD opportunities to anybody that wants to learn. There has been a massive increase in the CPD offered during the pandemic, and I do not want to see this decrease as we move closer to a normal life.

At SPD LTD, I wanted to ensure that people could still take part in training with me, even if they are back at work. So, alongside my live sessions, I have taken the step of breaking down my training webinars in to 10–15 minute modules, which can be watched on demand. This means that contractors will have the option of partaking in a live session with me where that can ask real time questions, or if the times and dates don’t suit, they can log in and do the training session in their own time then contact me directly with any questions.

I would like to see more manufacturers offering CPD as a way to help the industry, rather than a sales exercise. I have given training to contractors and consultants that have openly told me they don’t use my company’s products. What is important to me, is that the education is there to ensure that the correct devices are selected and installed, that people understand the wiring regulations regarding surge devices and understand why they are being installed, not what brand of SPD is being used.

As much as we are all looking forward to being back to normal, I hope that as an industry going forward, we won’t forget the value of CPD and its importance to ensure that we, as an industry, stay relevant and up to date.