ABB introduces the next generation of monitoring equipment for surge arresters: EXCOUNT-III, utilising unique features previously unseen on the market.
Interest for online surge arrester monitoring is growing, and so the EXCOUNT-III Surge Counters have been designed to fulfil this need by providing the user with remote real-time monitoring of arresters as well as useful input to the insulation co-ordination of the station as a whole.
Surge Counters are used to monitor the health of Surge Arresters and protect against potentially damaging events which could lead to deterioration and ultimate overload. It is important to also schedule regular checks of surge arresters including visual inspection and diagnostics to detect and prevent a costly power outage.
The EXCOUNT surge counter range draws upon over 70 years of experience by ABB in the development of arresters and associated accessories. Safety, functionality and longevity are key elements which are given priority in selection and design of components. In stark contrast to many other competing products, the EXCOUNT surge counters has not neglected short-circuit safety which lies inherent in the design concept.
With market pressure on utilities to obtain near 100% power availability, taking all actions to avoid even a rare unplanned outage is vital. As users push their systems harder accordingly, it can be expected to see stresses from system events leading to the arresters also being called upon to act more often than they perhaps did in the past. Monitoring how they handle those stresses – as well as what the consequences of those events are on the system itself – may be included as part of the user’s strategy for improving the overall availability. EXCOUNT-III has been developed with this strategy in mind.
EXCOUNT-III is a complete remote real-time surge arrester monitoring, diagnostics and analysis system. It permits the registration of the total number of discharges, the surge amplitude and wave-steepness, the date and time of occurrence, the total leakage current as well as the resistive leakage current through the surge arrester. In addition, the equipment can be used to define the residual voltage across the arrester for the actual surge, which in turn can be used to better estimate overvoltages in the station for a more detailed insulation co-ordination evaluation.
Not only does the EXCOUNT monitor the arrester itself, it can also give an estimate of overvoltage occurring at nearby apparatus within the arrester’s protection zone – providing valuable information about whether the protection against potentially damaging surges is sufficient or not. In this way, EXCOUNT-III provides the user with remote real-time monitoring of arresters as well as useful input to the insulation co-ordination of the station as a whole.
ABB EXCOUNT-III surge counter supports the protocol IEC 61850, Ed. 2, and communicates remotely via the fibre optic cable to permit the user to add signals into an existing data collection system (SCADA). Enabling remote retrieval of data, EXCOUNT-III eliminates the need for substation visits solely to monitor surge arrester condition, while also enabling the highest possible personnel safety standard by not having to approach an energized arrester to perform online diagnostic measurements.
The EXCOUNT-III system consists of individual sensors that are connected by an optical fibre connection. Each sensor can be interrogated individually and be integrated to existing SCADA system. For use with all makes and types of gapless arresters.
EXCOUNT-C |
EXCOUNT-I |
EXCOUNT-II |
EXCOUNT-III |
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For each surge arrester it is fitted on, the advanced version (EXCOUNT-IIIA) registers the total number of discharges, the surge amplitude and wave-steepness, the date and time of occurrence, the total leakage current as well as the resistive leakage current through the arrester by thirdharmonic analysis (method B2 according to IEC 60099-5). Using high speed sampling and sweep time, complete surge current impulses at the arrester’s connection point are recorded and available for analysis.
The standard version (EXCOUNT-IIIM) is available for users who do not desire to analyse the overvoltages in detail. With this, discharges are only categorized by their amplitude along with a date and time stamp of occurrence. Other generic features are the same between the versions.
A web browser interface via an optical fibre connection permits online interrogation and data analysis from each unit individually and is also used for configuration setup. The introduction of smart grid and the communication protocol IEC 61850 has made users more focused on integration with existing SCADA systems. EXCOUNT-III supports this protocol and communicates remotely via the fibre optic cable to permit the user to add signals into an existing data collection system.
Excount-III ABB Surge Counters
In addition to surge counting, a special feature of the advanced version is the registration of the surge amplitude and wave-steepness. This can be used to define the residual voltage across the arrester for the actual surge, which in turn can be used to better estimate overvoltages in the station for a more detailed evaluation of insulation coordination than has been possible in the past.
This added-value feature will help users to verify if they have adequate protection or if they need to reconsider their choice of arrester or even increase the number of arresters in the station. Furthermore, there is particular interest to correlate front time and overvoltage levels with pre-existing transformer monitoring equipment as a means to support total system condition monitoring diagnostics.
EXCOUNT-III gives the user the possibility to measure both the total leakage current as well as the resistive component of the current through the arrester. The measurement of the resistive current especially gives a good indication of the arrester’s condition and fitness for continued service. With the aid of the SCADA system, these measurements can readily be used to co-ordinate maintenance work and possible replacement in order to assist with minimizing unnecessary and costly unplanned outages.
EXCOUNT-III remote retrieval of data via the optical fibre cable eliminates the need for substation visits solely to monitor arrester condition, while also enabling the highest possible personnel safety standard by not having to approach an energized arrester to perform online diagnostic measurements. All components are housed in a sealed, weather-proof case, suitable for outdoor use. The base unit is mounted on the support structure and interconnected similar to a traditional counter, while the separate field probe is fixed at the bottom of the arrester. An external power connection from the station auxiliary supply (100 – 250 V, AC or DC) as well as a fibre optic cable connection are additionally to be provided by the user.
T&D are Specialist Distributors of LV MV HV Cable Installation, Jointing, Substation & Electrical Equipment – we supply companies in the onshore and offshore wind, solar, rail, oil/gas, data centre, battery storage and utility sectors with products to enable the energisation, operation and maintenance of underground cables and overhead lines.
Products | Surge Counters | Sealing Cable Ducts | Cleats, Clamps & Hangers | LV MV HV Electrical Safety | Arc Flash Clothing & PPE | Jointing, Termination & Stripping Tools | Cable Pulling & Laying | Feeder Pillars | Cold Shrink | Heat Shrink | Joints Terminations Connectors MV HV
HV Joints Terminations Connectors | 11kV/33kV up to 66kV Ex Stock
Top 5 Challenges In Wind Power Cable Management
Roxtec Top 5 Challenges
Thorne & Derrick are Approved Distributors for Roxtec, the leading manufacturer of sealing solutions for cables and pipes, to protect electricity Transmission & Distribution assets including windfarm substations against water ingress, gas migration and fire hazards.
Below Roxtec have compiled the top 5 most common issues we all struggle with on offshore substations.
1. Specifications & Certificates
We all want to ensure safety and operational reliability, and use high quality products to deliver the best result we can. Therefore, we often meet specifications and requirements demanding a multitude of certificates. However, it is not guaranteed that all types of cable sealing methods are approved.
The best thing would be to find a sealing solution that has passed all tests and certifications.
2. Uncertain Estimates
It can be difficult to know how many cables or pipes, or what size power and instrumentation cables, we need to route. We can never be sure about making the right openings, or about how to seal all those penetrations. Even the best of estimates cannot predict all late design changes.
What we need is a sealing system that is as adaptable as possible to the number and size of cables, pipes or openings. It should be so flexible that we would be able to have spare capacity.
3. Hard Cables To Handle
It is difficult, or almost impossible, to move and bend a large high-voltage or medium-voltage power cable into the desired position for routing through a deck or bulkhead. It takes a lot of time to reorganize the routing path in order to gain a couple of millimeters of bending radius.
What you need is a solution where you can position and apply a seal to fit around the cables, even if they are in an off-center position.
4. Tricky Design Work
Given the issues mentioned above, the work of design engineers often becomes a nightmare. We need to plan, calculate and design in cable and pipe penetrations at an early stage considering both rollout and maintenance. Sometimes, it means recalculating each opening.
Imagine a web-based design tool that we can use to design and redesign transits in no time.
5. Time-Consuming Installation
We know renewables can save the climate, and we know speed is crucial and time is money. Therefore, it is so frustrating to struggle with sealing solutions that are neither flexible nor easy to install. We cannot accept that project plans fail due to complicated installation work tasks. We should only engage suppliers of user-friendly products who will also train the installation team.
Roxtec provides offshore wind farms with an “all in one” solution for cable entry sealing, cable management and vibration damping. Standardise with Roxtec seals for efficient offshore windfarm cable protection design, quick roll-out and certified protection – cables are securely fixed, sealed and cable lifetime is extended.
Thorne & Derrick are Specialist Distributors to the UK and international Offshore Wind & Renewable industry to provide safe and reliable
LV HV Electrical Cable & Power Distribution Systems up to 66kV – we are highly customer responsive and absolutely committed to providing a world-class service.
Contact our UK Power Team for competitive quotations, fast delivery from stock and technical support or training on all LV-HV products.
Key Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV
See how T&D support, supply and service the Renewable Energy industry.
ENERGYx2022 North | Chester Racecourse | 21st September 2022 | Book Now
What: ENERGYx2022 North | Electrical Industry Event
Where: Chester Racecourse, New Crane Street, Chester, CH1 2LY
When: Wednesday 21st September 2022 09:00 – 16:00
Exhibition Space Bookings: BOOK NOW
Free Delegate Attendance: BOOK NOW
ENERGYx2022 North is an Exhibition and Conference for anyone working within the Electricity Industry (distribution network operators, private network operators, energy transmission, renewable energy, telecommunications, and rail companies). This Net Zero event combines Overhead Lines, Plant and Cables as well as featuring the Health & Safety aspects.
Thorne & Derrick are delighted to announce that we are exhibiting at ENERGYx2022 North taking place this September at Chester Racecourse. Earlier in the year we were Exhibition Sponsors for ENERGYx2022 South in Chester. We would like to take this opportunity to invite our supply chain to attend this prestigious event.
Thorne & Derrick will be showcasing a range of products including the Strutslayr Rigid Tool, HV Joints, Terminations and Connectors, Arc Flash PPE & Electrical Safety Equipment and Cable Jointing Tools.
There is much to see and do at ENERGYx2022 North, be that hear from leading industry figures, meet the best of the supplier base, take part in practical health and safety demonstrations, and sample the food drink and entertainment available at the Networking event the evening prior.
This event will be attended and supported by a wide mix of people working in Electrical Utilities, Network Operators, DNOs, Railway Companies, Transport Specialists, Renewable Companies, Civil Works, Health & Safety, Telecom, data centres and Industrial Manufacturers with private networks.
Following on from ENERGYx2020/21, COP26 and the UK government’s drive for us all to reduce the use of fossil fuels ENERGYx2022 will be a great place to benchmark our progress. The challenges reaching Net Zero creates for transmitting and distributing electricity whilst maintaining safe and reliable networks, though not insurmountable requires a lot of joined up and collaborative thinking.
With the proliferation of working from home it has become more difficult to meet and network with potential customers and suppliers and therefore events such as ENERGYx and The Electrical Engineers Circle have grown in importance.
Contact Louise Purcell Events Director at Energy Network Events Limited to discuss further:
Tel: +44 (0)121 736 0411
Mobile: +44(0)7581 779661
Email: [email protected]
Liam O’Sullivan – Licence Director, SP Manweb, SP Energy Networks
Liam O’Sullivan is the Licence Director for the SP Manweb area for SP Energy Networks. He started his professional career in ScottishPower in 2000 and has gained a wealth of experience in several senior roles, in both the Retail and Networks businesses, including Customer Collections, E-Commerce, Network Operations, Customer Connections and Large Capital Investment Projects.
In his current role, he is responsible for the electricity distribution network in North West England, North and Mid Wales. As a result of the decarbonisation of transport and heat networks, demand and reliance on our electricity network infrastructure is expected to increase significantly. Liam is committed to ensuring a smooth transition to low carbon technologies for all industrial, commercial and domestic customers in Merseyside, Cheshire, North Shropshire and North Wales.
Cara Blockley – Head of DSO Strategy, Electricity North West
Cara has been with Electricity North West for 14 years working in network innovation and transition to distribution system operations for the last 8 of those. Cara has responsibility for the teams who are charged with leading the North West to Net Zero.
This means ensuring we understand what the needs of our customers will be in relation to network capacity requirements, seeking innovative, flexible solutions to those requirements through running tenders for flexibility and supporting the adoption of low carbon technologies.
Geoff Murphy – Head of Delivery for Low Carbon Technology and Low Voltage Cables, SP ENERGY Networks
Geoff is currently the Head of Delivery for Low Carbon Technology and Low Voltage Cables in the SP Manweb Licence Area. He is a Chartered Engineer that has worked for SP Energy Networks for 18 years.
During this time, he has held several varied positions within the organisation, with a strong focus on developing, trialling an implementing innovation strategies and solutions.
Kailash Singh – Lead Engineer – Future System Strategy, SP Energy Networks
Kailash Singh is a Lead Engineer within Future System Strategy team at SP Energy Networks. With over 15 years of industry experience, Kailash is specialised in power system planning, design, and network innovation.
At SP Energy Networks Kailash is involved in development of the state-of the art Engineering Net Zero (ENZ) Model which underpins Load Related Expenditure (LRE) within SPEN’s RIIO-ED2 Business Plans. Kailash has been instrumental in development of SPEN’s flexible network planning process and have been involved in assessment of over 1.5GW of flexibility capacity across both distribution license areas of SPEN.
Professor John Barrett OBE
John is a Professor in Energy and Climate Policy at the Sustainable Research Institute, University of Leeds with over 20 years of experience in energy and climate policy. John’s research interests include energy demand, resource productivity, energy and economy modelling, carbon accounting and exploring low carbon transitions.
John has been the Director of a number of large research centres that has employed a range of modelling approaches to understand how changes in production and consumption can contribute to a low carbon future. John was the Director of the Centre for Industrial Energy, Materials and Products (CIE-MAP – www.ciemap.ac.uk), a £4 million initiative funded by the UK Research Council. The centre explored how using material and products differently could contribute to the UK carbon targets. John is now a Co-Director for the Centre for Research in Energy Demand Solutions (CREDS – www.creds.ac.uk). This £19 million initiative is a new research centre established in 2018 with a vision to make the UK a leader in understanding the changes in energy demand needed for the transition to a secure an affordable, low carbon energy system.
John’s research is applied in various arena having been an advisor to a number of UK Government departments, Government Select Committees and agencies such as the Committee on Climate Change. John’s research team are responsible for providing annual headline Government indicators, including an indicator on “Consumption-based GHG emissions” and “Resource Productivity”. His research findings have provided evidence and influenced many Government publications related to energy demand projections, climate policy and resources and waste strategies. John was also a lead author for the International Panel on Climate Change, Working Group III.
Helen Gaier-Laidlaw – Licence Programmes Manager, SP Energy Networks
Helen is responsible for the development and delivery of investment programmes for SP Energy Networks including Overhead lines, vegetation management, telecoms, civils, Low Carbon Technology connections and investments including EVs and heat pumps.
Management of budgets, asset and business performance as well as preparing for the next Price Control contract from Ofgem and enabling SP Energy Networks transition to Net Zero.
Tom Walsh – District General Manager – Scottish Power
Tom leads a multidiscipline team to build, operate and maintain the EHV, HV & LV electricity distribution network in Merseyside and delivering a world class customer experience.
Tom is an experienced GM with a demonstrated history of working in the construction and utilities industries.
Guy Shapland – Lead Commercial and Policy Analyst, SP Energy Networks
Guy started his career in Manweb in 1993 as an apprentice jointer and has worked in many areas throughout his time. More recently Guy has been taking a lead role in developing the processes and systems to manage the procurement and operation of flexibility services.
Jason Hicks – Offshore Network Strategy Manager, National Grid ESO
Jason started his career at National Grid in 2011. During this time, Jason has been responsible for producing the Network Options Assessment (NOA) signalling the future transmission network requirements needed to deliver the renewable energy revolution.
With 10 years’ experience in onshore network planning Jason recently pivoted into the offshore network planning space. Since then, Jason has developed the Holistic Network Design, a first-of-a-kind plan to coordinate the connection of 23GW of offshore wind and recommend the key onshore and offshore infrastructure requirements necessary to facilitate the Government’s ambition of connecting 50GW of offshore wind by 2030.
In his current role, Jason is continuing to develop the strategy that delivers a future offshore transmission network, unlocking access to large volumes of renewable generation and paving the way to Net Zero.
Simon Sutton
Simon has over 25 years’ experience in the electricity transmission and distribution industry predominantly in the cables sector. He has worked in the cable materials supply industry, as the cables policy manager for a transmission utility and in the research sector. His interests also include condition monitoring, diagnostic testing, forensics and asset management.
Simon now works as Director of Professional Services for Altanova and is based in the UK. His responsibilities include business strategy, external relationships, and the coordination of technical activities around the world.
Simon holds a degree and PhD in Physics both from the University of Reading. He is active in International professional bodies and recently became chairman of CIGRE Study Committee D1, Materials and Emerging Test Techniques. He is also a member of the editorial board of the IEEE Electrical Insulation Magazine and a Visiting Senior Research Fellow at the University of Southampton.
Sebastian Ebert – M Sc of Engineering / Diplom-Ingenieur Elektrotechnik (FH)
Sebastian graduated from the University of applied sciences Zittau, Görlitz (Germany) as a Electrical Engineer and has worked in the industry for nearly 20 years in Germany and across the world. He has been with Suedkabel since 2019 and as a keen environmentalist he and his team want to play their part in helping with the drive to Net Zero.
Based on what we learnt at previous ENERGYx events we thought it fitting to have a speaker from a world class manufacturer, Suedkabel, who have been producing high quality cables and accessories for more than 120 years.
Sebastian will speak about the importance of maximizing the use of European power cable system manufacturing with technological leadership and sustainable advantage as contribution to meet the climate targets to drive the energy transition in the UK and in Europe.
T&D are Specialist Distributors of LV MV HV Cable Installation, Jointing, Substation & Electrical Equipment – we supply companies in the onshore and offshore wind, solar, rail, oil/gas, data centre, battery storage and utility sectors with products to enable the energisation, operation and maintenance of underground cables and overhead lines.
Products | Sealing Cable Ducts | Cleats, Clamps & Hangers | LV MV HV Electrical Safety | Arc Flash Clothing & PPE | Jointing, Termination & Stripping Tools | Cable Pulling & Laying | Earthing– Tapes | Rods | Bars | Feeder Pillars | Joints LV – Cold Shrink | Resin | Heat Shrink | Joints Terminations Connectors MV HV | Tools – Cutting | Crimping
HV Joints Terminations Connectors | 11kV/33kV up to 66kV Ex Stock
Portable & Fixed Gas Detection Monitors from Crowcon
Introduction
The Paris Agreement on climate change holds nations accountable for reducing their greenhouse emissions and reliance on fossil fuels, thus driving them to invest and use renewable energies, such as solar and wind.
However, the sun doesn’t always shine and it’s not always windy – or it might be very sunny or windy, leading to over-supply of the grid. To ensure that renewables are used for maximum benefit, any excess energy they produce (i.e., that isn’t needed for the grid at that time) is stored in local storage facilities, which take the form of large batteries.
These release energy later – when the grid requires more power, or when there is less sun or wind, such as overcast nights or calmer, duller days. However, these batteries can only release energy for a few (between 1 and 12) hours, so their use is limited to short-term, energy-on-demand requirements.
Batteries are effective at reducing power outages since they can also store excess traditional grid energy. The energy stored within batteries can be released whenever a large volume of power is needed, such as during a power failure at a data centre to prevent data being lost, or as a back-up power supply to a hospital or military application to ensure the continuity of vital services. Large scale batteries can also be used to plug short-term gaps in demand from the grid.
These battery compositions can also be used in smaller sizes to power electric cars and may be further scaled down to power commercial products, such as phones, tablets, laptops, speakers and – of course – personal gas detectors.
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Transportation | Welding |
Battery technologies can be segregated into four main categories:
Chemical – e.g. ammonia, hydrogen, methanol and synthetic fuel
Electrochemical – lead acid, lithium ion, Na-Cd, Na-ion
Electrical – supercapacitors, superconductive magnetic storage
Mechanical – compressed air, pumped hydro, gravity
The range of portable gas detectors and portable monitors for personal and temporary gas monitoring from Crowcon, consists of a wide range of single and multi gas products.
This range of portable gas detectors are used to protect staff and personnel in many industries (including battery storage) around the world and are specified to ensure that each product is fit for purpose.
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The Gasman personal monitor manufactured by Crowcon is a compact and fully ruggedised single gas detector for the toughest of industrial environments – the gas detector is compact and lightweight design for industrial gas detection in battery storage, oil and gas, chemical plants (with exotic gases), steel works (special CO sensor), hospitality (CO2), renewable energy (hydrogen) and waste and water works. More about Crowcon Gasman |
| Gas-Pro portable gas detector is designed and manufactured by Crowcon for confined space entry monitoring and can detect up to 5 gases. The Crowcon Gas-Pro offers a compact and rugged solution for works and fleet managers entering confined spaces. More about Crowcon Gas-Pro |  |
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Crowcon T4x is a new and improved portable multi gas monitor you can take almost anywhere. Now with added industry leading sensor technologies to improve worker safety and cost you less over time. Exclusively with long-life O2 and MPS™ sensor technologies.
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| The Crowcon Tetra 3 portable gas detector is a compact, robust and simple to use multigas monitor. The Crowcon Tetra 3 mainly detects the common four gases (carbon monoxide, methane, oxygen and hydrogen sulphide), but also an expanded range: ammonia, ozone, sulphur dioxide, H2 filtered CO (for steel plants) and IR carbon dioxide (for safe area use only) – this portable gas detector is specified in harsh environmental conditions. More about Crowcon Tetra 3 |  |
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The T4 is a portable gas detector manufactured by Crowcon which provides a personal gas detection solution against four of the most common gas hazards – carbon monoxide, hydrogen sulphide, flammable gases and oxygen depletion. The T4 also now has improved detection of pentane, hexane and other long chain hydrocarbon. This portable gas detector offers compliance, robustness and a low total cost of ownership. More about Crowcon T4 |
Portable gas detectors are typically smaller, handheld devices that provide gas detection in smaller locations and are often used in confined spaces or working areas – mobile, transferable and transportable. Crowcon Gas-Pro portable gas detector is designed for confined space entry monitoring and can detect up to 5 gases. The Crowcon Gas-Pro offers a compact and rugged solution for works and fleet managers entering confined spaces.
Fixed gas detectors manufactured by Crowcon have been proven in many harsh environments around the world and are used in industries such as offshore, oil and gas, petrochemical as well as steel mills and chemical plants.
The range of fixed gas detectors from Crowcon are suitable for detecting single and multi gases and can be configured to suit specific requirements – including hazardous area workplaces according to ATEX and IECEx Certification.
| Crowcon Xgard is a versatile range of fixed gas detectors which meet gas detection specifications for a wide range of applications and industries worldwide. The Crowcon Xgard can be found in research facilities, water treatment, power, oil and gas and manufacturing facilities. More about Crowcon Xgard |  |
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Xgard Bright is a versatile platform offering flammable and toxic gas detection and oxygen monitoring, while providing ease of operation and reduced installation costs. The Xgard Bright is now available with MPS (Molecular Property Spectometer™) technology. |
| The Crowcon XgardIQ is an intelligent and versatile fixed gas detector for the detection of seven different gases dependent upon product setup. Gases include CO, H2S, H2, HF, LPG, CH4 and O2. There is a non-intrusive calibration where functions are performed via the display and keypad, without the need for a hot-work permit or any special tools. More about Crowcon XgardIQ |  |
Crowcon gas detectors, both fixed and portable, provide life saving alerts and notice of the presence of potentially fatal gases in working areas. Typically, a fixed gas detector is used as a permanent gas monitoring solution installed in a specific location such as a process area of a control or a plant room.
Dangers
Li-ion battery fires
Leakage of toxic gases prior to thermal runaway
Hydrogen and explosion risk
Panels | Plugs | Isolators | Enclosures | Lighting | Control Stations | Motor Starters | Heat Trace | Gas Detection | Flame Detection | Process Instrumentation | Process Heating | Fans | Security Locking & Access Control
In this article, Castell discusses how trapped key interlocking is implemented within switchgear control whilst maintaining system integrity.
Factors such as aging infrastructure, technological advancements, lack of investment, demands for cleaner and reliable ever-present energy, have significantly altered the scenery of the energy sector with switchgear systems becoming increasingly complex.
Switchgear systems can utilise or involve several incomers, earthing systems, making the integration of HV (High Voltage), MV (Medium Voltage), LV (Low Voltage) or switching incomers and common supply busbars potentially complicated. This not only increases the potential level of complexity but also the need for robust and reliable safety systems to ensure personnel safety, electrical equipment protection and its correct, safe mode of operation at all time.
The safe and effective operation of switchgear can be achieved through a sequential release system which sets out a process that must be followed removing the need for reliance on work instructions alone.
The system designer should consider the operational processes in conjunction with the safe state of equipment. A challenge with switchgear if one or more supplies shuts down due to an overload or power failure or for planned maintenance purposes is that the remaining supplies will have to carry the load. Therefore, the sequence of operation must be controlled in such a way to ensure that power is maintained, the shutting down of the remaining supplies due to overload is avoided and the collapse of the entire system is prevented.
Trapped key interlocking constitutes an effective way to control the sequential operation of switchgear systems. A trapped key interlocking system can ensure a process is followed and cannot be circumvented. The transfer of a key ensures that wherever personnel find themselves, in either starting or shutting down operations, they can be assured that they are safe through the control of switchgear isolation.
Management of complex switchgear systems can be controlled through a blanking system. The blanking system means that some of the symbols on the busbar locks have a part coded lock which denotes it can be isolated by more than one of the keys forming the switchgear system.
For instance, if we part coded a lock to A ‘Blank’ we can use any 2-character symbol keys with a prefix of ‘A’ to operate the lock (see below for more examples). The system’s integrity is maintained by the design of the nomenclature chosen for the incomer and busbars.
This means the open and closing operation of the switchgear can be controlled with less locks and keys. Blanking systems, although not suitable for every switchgear application, offer some significant advantages. More specifically, they remove the need for excess keys and additional key exchange boxes allowing for a simpler interlocking system. Implemented correctly, they can also provide cost and time saving benefits.
Applications for incomer and busbar interlocking or incomer, generator and busbar interlocking are used in any environment where there is a demand for reliable energy sources such as data centres or building management services like factories, hospitals, airports, rail and stadiums.
This system requires five locks and three keys. In the normal operation the keys are trapped in the incomers in the closed position and both bus couplers are open.
The symbol sequence will allow appropriate incomers to be open allowing the key to be released, transferred and inserted and trapped to the associated bus coupler allowing it to be closed. The symbols used here are AA, AB and BB for the Incomers and A_ (A BLANK) and _B (BLANK B) for the bus couplers.
This system will require four locks and two keys. The keys are trapped in incomer 1 and 2 with the switches in the closed position.
Both the bus coupler and incomer 3 open.
The symbol sequence will only allow incomer 3 or the bus coupler to be closed after the appropriate key has been released, transferred and inserted into the bus coupler or incomer three lock.
The system ensures that only two incomers are supplying at any time.
The symbols used here are AA and AB for the incomers and A_ (A BLANK) for the bus coupler.
The normal operation is the two incomers are closed with bus coupler and generator are both open. The symbol arrangement using key symbols AA, AB, A_ (A Blank) on locks with just keys AA AB will ensure safe switching operation.
It will not be possible to have incomer 2 and generator closed at the same time to avoid paralleling.
The symbols used here are AA and AB for the incomers and A_ (A BLANK) for the bus coupler.
The design of an interlocking system is a process that must be carefully undertaken. A good interlocking scheme requires all risks and operational procedures are considered in advance ensuring integrity. This can proactively address how the system will respond in both operational and failure modes along with routine maintenance.
An interlocking system will set out the process and steps that must be followed to ensure personnel cannot access potentially dangerous areas. When maintenance activities are being performed, trapped key interlocking systems can ensure that the switchgear system is always put in a safe state. Trapped key also ensures that the system operates efficiently and there is no chance of, for example, switching two incoming feeds on to a common busbar significantly reducing risks (such as fire, arc flash) as well as the possibility of equipment damage.
Complicated switchgear systems need to have a robust management system to protect personal and machinery. Designed correctly, an interlocking scheme can contribute to eliminating human error on site while permitting safe access to electrical equipment. Integration of older equipment with new switchgear can be a challenge, trapped key interlocking allows for the safe integrating with OEM switchgear, ensuring safe site operations and negating the need for complicated controls.
Castell have been delivering safety solutions for switchgear since 1922. Working closely with original equipment manufacturers (OEMs) has enabled Castell to produce interlocks designed specifically for use on the leading manufacturers own breakers, isolators, disconnectors and earth mechanisms. Castell offer a range of isolation products for switchgear applications.
The FS lock range can perform in the harshest environments using figure symbols as the unique identifiers enables defining a unique blanking system which allows for easier use of switchgear within the integrity of the trapped key system. FS locks can be incorporated into all Castell product for isolation equipment. Where isolation requires an un–masterable solution on switchgear, Castell Q range offers the ability to uniquely code locks to site requirements and as with the FS range, the Q range of locks can be used on all Castell isolation products.
To discuss any switchgear application requirements please contact our team of technical experts: [email protected] or visit our website: https://www.castell.com/
HazardEx supports hazardous area and process industry professionals and are the leading technical authority on explosive atmospheres – protecting people and plant through a series of Exhibitions, Conferences, Workshops, Seminars and Webinars across the globe.
HazardEx is where industry leaders meet to discuss and engage to ensure workplace and worker safety in potentially explosive atmospheres.
T&D are Specialist Distributors of LV MV HV Cable Installation, Jointing, Substation & Electrical Equipment – we supply companies in the onshore and offshore wind, solar, rail, oil/gas, data centre, battery storage and utility sectors with products to enable the energisation, operation and maintenance of underground cables and overhead lines.
Products | Surge Counters | Sealing Cable Ducts | Cleats, Clamps & Hangers | LV MV HV Electrical Safety | Arc Flash Clothing & PPE | Jointing, Termination & Stripping Tools | Cable Pulling & Laying | Earthing– Tapes | Rods | Bars | Feeder Pillars | Joints LV – Cold Shrink | Resin | Heat Shrink | Joints Terminations Connectors MV HV | Tools – Cutting | Crimping
HV Joints Terminations Connectors | 11kV/33kV up to 66kV Ex Stock
Published 12 Mar 2026
Compound Box Filling Compound end boxes rarely get attention — until one fails. Across ageing networks, replacement of compound-filled end boxes is becoming more frequent, particularly where original insulation systems have deteriorated and air insulation is not practical because...
Published 06 Mar 2026
Nexans 240–300mm² Multi-Joint – Medium Voltage Cable Joint Installation Medium voltage cable jointing requires reliability, consistency and safe installation practices. The Nexans 240–300mm² Multi-Joint is designed to simplify medium voltage jointing while maintaining high electrical performance for demanding power...
