Power resistor manufacturer development!

Telema S.p.A has appointed Andrew Keith, former engineering director at the group’s subsidiary company, Cressall Resistors, as its new group product development director.

Andrew Keith

The Telema group forms the largest resistor manufacturing group in the world, spanning across 20 countries with over 1,500 employees. In the newly created role, Keith will collaborate with companies from across the group to develop a standardised range of load banks.

A load bank is an electrical load made from resistors, inductors or capacitors, or a combination depending on the application. Its purpose is to validate that an electrical power source will perform correctly to full capacity, this can be either upon completion of manufacture, installation or as part of on-going maintenance.

Each subsidiary part of the group has its own wealth of knowledge and experience in delivering bespoke power resistor solutions for the most demanding of applications. Keith’s work will build upon these individual successes and will use the expertise of each company to develop a standard range of load banks that will suit the wider marketplace.

After starting at Cressall in 2007, Keith worked on a variety of projects before progressing to the position of engineering manager and then to his latest director role. During his time at the company, Keith specialised in the design and manufacturing of power resistors for electricity transmission and distribution and for industrial applications. This included work on bespoke designs for Neutral Grounding Devices (NGR / NER), Harmonic Filtering Resistors, Dynamic Braking (DBR) and load banks.

The abundance of experience that Keith gained at Cressall will be of great benefit to his new role, which will begin with a research project that will see him work across the entire group in order to create a new range of standardised load banks for multiple sectors. This project is the first to be conducted across the group, allowing each subsidiary to build upon the others experience and offering.

On his new appointment, Keith explains, “the newly created role is a positive investment for the group and marks an exciting opportunity to bring together the expertise and resources of the Telema subsidiaries to offer our customers the benefits of our shared knowledge.

“By making the most of each member of the group’s own proficiencies in the load bank field, my new role will help to bridge the gaps between each company’s individual expertise, to create a standardised product that will also help to fill a gap in Telema’s existing product range”.

Following the extensive research of each company’s offerings, Keith’s work on the development of a standardised product will enhance the value of the group’s product range which will, in turn, contribute to an increase in sales.

#Telema @CressallR #Electronics @StoneJunctionPR

Engineer brings FEA expertise to resistor manufacturer.

To mark another successful year, power resistor manufacturer Cressall Resistors has appointed Damiano Natali as research and development and finite element analysis (FEA) engineer. Natali relocated from Genoa (I) to join the Leicester-based company (GB) after working as a computational fluid dynamics (CFD) engineer for three years. He also has a PhD in Fluid Dynamics and Environmental Processes from the University of Genoa.

Damiano Natali

Since joining the team in November 2015, Natali has already developed a complex piece of R&D software that allows the department to accurately record test voltage waveforms. The software increases the productivity of the testing process, enhances the reliability of the outcomes and increases the precision with which Cressall meets customer specifications. The software, coined by Natali as CR Lightning also allows Cressall engineers to quickly verify that tests comply with BS EN 60060 requirements.

In a constantly evolving marketplace, ensuring its product range is both cost-effective and flexible enough to satisfy its customers' technical and commercial requirements is one of Cressall's main focuses. To stay ahead, the resistor manufacturer recently invested in advanced software packages, including Ansys Workbench. This, along with the guidance of Cressall engineers, will help Natali develop Cressall's innovative products even further, as well as optimising their existing product range.

"So far, Damiano has had an enormous impact on the Cressall team," explained Andrew Keith, engineering director of Cressall Resistors. "Damiano has a wide skill set, ranging from the ability to accurately analyse raw materials, to conducting advanced CFD operations effectively.

"Damiano joins the team at an exciting time, and the biggest impact of his initial work will come in the next few months, when he will use our 3D modelling and FEA software to optimise an existing design as part of one of our largest projects to date."

In his spare time, Natali is an enthusiastic cyclist and is keen to tackle some of Leicester's toughest cycling routes, including Beacon Hill and Polly Botts Lane.

"Cressall is one of the leading manufacturers for resistor production and its worldwide customer base and wide range of product requests was certainly appealing when considering the job prospect," commented Natali. "At Cressall, I have the opportunity to apply my mechanical engineering background to a wide spectrum of applications, such as the seismic analysis of resistor enclosures, to wind loading on high-stacked banks."

@CressallR #PAuto 

Staying grounded!

A cost-effective range of neutral earthing resistors (NERs) has been designed by Cressall to help generator manufacturers and end users around the world protect distributed generation systems. The NERs have been specifically designed to be supplied with multiple vacuum contactors, for applications requiring the earthing of multiple parallel-connected generators.

NERs are used in medium-voltage AC distribution networks to limit the current that would flow through the neutral point of a generator in the event of an earth fault. The resistors limit fault currents to a value high enough to be detected but low enough to prevent damage to switchgear or generators.

These switched NERs have been designed as a cost-effective method of providing a single resistance earth for generators that are connected in parallel.

When generators are connected in parallel, there are typically three options for earthing - using a single fixed earthing point, earthing all of the neutrals or using a single earthing point through individually switched neutrals. Using a Cressall switched NER gives the user the flexibility to select which generator is to be earthed. Because there is only one earth path, protection relay coordination is straightforward and the risk of damage due to circulating currents is reduced.

Applications for Cressall’s NERs range from backup supplies for airports and hospitals to generation for small towns and industrial centres that are too far from the main grid.

“As the price of energy increases, so does the requirement for alternative sources,” explains Martin Nicholls, sales director of Cressall. “For example, in remote applications it is not cost effective to build and maintain power transmission lines over long distances. Therefore, remote diesel or natural gas generators are used, operating independently off the normal grid. These effectively mimic a normal power station, only smaller.

“We have been supplying switched NERs for standby and combined heat and power projects for more than 20 years; however the demand for cost effective solutions for multiple point earthing resistors led us to introduce this modular range. Previously when earthing of multiple generators was needed, the main option was to source fully specified metal clad switchgear and package it with a stand-alone resistor, which makes the project large and very expensive. By creating and developing a standard range, Cressall has improved the response time to customers, shortened delivery times, lowered cost and improved quality.”

New MD for power resistor!

Cressall Resistors has appointed Simone Bruckner as managing director. Bruckner relocated from Italy earlier this year to join the company, bringing with him 15 years' experience working in the marine and oil and gas industries. The appointment follows a successful year for Cressall, having recently launched a new, on-site research and development (R&D) department.

Simone Bruckner 

After serving in the Italian Navy, Bruckner began working as a project engineer for Fincantieri, the largest Italian shipbuilding company. It was here that Bruckner developed the valuable design and production skills that would help him throughout the rest of his career.

Bruckner later landed a managerial role at Azimut-Benetti, where he used his technical and project management skills to help develop new yacht prototypes and onboard systems. For ten years, he worked in various roles at Azimut-Benetti, before being approached by heavy metal products manufacturer, Fusani for the role of general manager.

One of Bruckner's biggest achievements to date is successfully leading the merger of Fusani and SIEM, a company focused on the oil and gas market. Bruckner's role included gaining an understanding of the new products that were to be sold as a result of the merger and passing this knowledge on to other employees. Bruckner also trained Fusani employees on the structure of the merged company and how to interact with new customers. Bruckner prides himself on the fact that, six years on, SIEM Fusani is still going strong.

"Moving to Cressall is the right thing to do at this point in my career," explained Bruckner. "Over the years, I have gained valuable R&D and project management skills that I can use to help Cressall continue competing in the worldwide industrial market.

"As a former rowing coach, it's in my nature to provide as much training and encouragement as employees need, so they can be confident and flourish in their work. My experiences recruiting from different industries will help bring diverse perspectives into the company, allowing us to maintain fast product turnaround in line with the UK standard.

"I haven't had much time to row since moving to Leicester, but I'll be sure to get back on board. In fact, I've been told by my new colleagues that the River Soar is lovely in the summer!"

International trade qualification brings expertise to resistor manufacturer.

Hard work and expertise in the field of international export has paid off at Cressall.  Hina Sharma of the company's commercial engineering team has achieved an International Trade Operations and Procedures (ITOPs) qualification.

ITOPs is a recognised international trade qualification that covers the main elements of export administration. This includes documentation, customs and excise - as well as other legal requirements - payments, dispatch and shipping.

The East Midlands Chamber of Commerce delivered the course in conjunction with Fidelitas Training.

Sharma, who began her career with an engineering degree at De Montfort University, is involved in post sales management, handling contracts and schedules and ensuring safe delivery at Cressall.

The Leicester based resistor specialist exports products worldwide with distributors in 17 countries, spanning four continents.

"For Cressall, exporting internationally is an incredibly important aspect of the business," explained Sharma. "In gaining my ITOPs qualification I've learned a great deal and have already started to implement small changes to the way we operate that will have a positive impact on our overall efficiency.

"The course has enabled me to take a step back and look at Cressall's international trade procedures from an objective point of view. The skills and knowledge I've acquired thanks to ITOPs will help Cressall operate internationally for years to come."

Sharma also achieved a British Chambers of Commerce Foundation Award in International Trade alongside her ITOPs qualification.

Power resistors added to range!

Anglia Components has added a range of power resistors covering 0.1W – 2000W following its appointment as the Britain and Ireland distributor for US specialist manufacturer Ohmite. Anglia will also offer Ohmite’s heat sink range, and will be able to support opportunities for custom resistors under the agreement.

M Series Heatsink

According to Anglia Marketing Director Graham Bridger, “Ohmite is one of the best regarded names in resistive components and our new relationship with them gives us a complete portfolio of resistors for high current, high voltage and high power applications. We believe Ohmite is the only company to include all four major power resistor technologies in its portfolio.  A key strength is their ability to produce custom resistors for specific applications. The relationship also widens our range of heat sinks.”

Peter Craik, International Sales Director for Ohmite, added, “Around 90% of our European sales is through distribution, and we take our relationships with our distribution partners very seriously. Anglia has convinced us that their strong team of Field Applications Engineers and their internal technical support desk can identify new opportunities for Ohmite and expand our market share. We also believe that their UK stock profile will be a great benefit for our UK customers. Ohmite believes that local and regional distributors can co-exist very successfully with larger global organizations, serving different parts of the market, and think that Anglia will be very successful with our resistive and heat sink products.“

The agreement between Ohmite and Anglia covers the full portfolio of over 10,000 product lines, including wirewound, wire element, thick film, and ceramic composition resistors as well as heat sinks, and rheostats. Ohmite offers axial, tubular, surface mount, and current sense resistors. Key elements of the range will be held in stock at Anglia’s  warehouse and can be ordered for same day shipment from Anglia Live.

Testing, testing, one two...

Exciting business growth at Cressall, has allowed the firm to launch a new research and development (R&D) department. The expansion comes about after long-serving test engineer, Michal Nowotny was promoted to R&D engineer earlier this year.     

Nowotny's promotion now means that more time and manpower can be devoted to Cressall's R&D projects at the newly equipped headquarters. The company has seen the demand for bespoke products skyrocket in the last few years. To respond to this industry need, Cressall has invested in its research, design and test capabilities. 

Newly implemented data capture systems provide a more accurate level of recording test results. The facility boasts computerised 32 channel data logging equipment where test variables such as temperature, power and current can be recorded within the system. 

Cressall’s new test facility provides it with the means to carry out impulse tests of up to 400,000 Volts in order to truly prove designs and test prototypes. Testing facilities also include ingress protection proving, in which a resistor enclosure is tested to ensure that water cannot harmfully penetrate it. 

Cressall's equipment ensures that a product complies with the IEC 60529 standard prior to being submitted to a third party accredited ingress protection test facility, if this is a specific customer requirement.

"The new test facility and data logging equipment allows us to carry our more tests and to record results more accurately," explained Michal Nowotny, Cressall’s chief R&D engineer. "In turn, this enables us to make more accurate predictions when designing resistors. When carrying out impulse testing for instance, we can make performance forecasts for different specifications scaled against our previous findings and results.

"We've come a long way here at Cressall; from having no R&D department, to now looking to expand the facility further. Part of the proposed move is based on our testing facility strategy which includes testing of the EV2 water cooled resistor, in which a dedicated test cell would have to be constructed. This is something we’re very keen to get up and running." 

ARCOL Resistors Extend Global Distribution with RS Components #Components

Arcol Resistors is increasing the availability of their power and specialist resistor range worldwide through closer cooperation with RS Components, widely recognised as the world's leading high service distributor of electronics and maintenance products.

The latest Arcol Resistor types to be added to the RS Components product range are the market leading RWS7 and RWS10 surface-mount resistors which have been uniquely designed to meet the rising power requirements for surface mount components.

The 7 watt RWS7 has a value range from R1 to 5K and the 10 watt RWS10 is available from R1 to 10K. Both types feature an optimised thermal design for greater efficiency, improved surge capacity and overload characteristics. TCR options available are ±20ppm/°C, ±50 ppm/°C, or ± 90 ppm/°C depending on resistor value.

Mike Pritchard, Commercial Director of Arcol Resistors, comments, "With operations in 32 countries and market-leading suppliers from across the globe RS Components will play a major role in extending our market reach. Their innovative online sourcing solutions and DesignSpark electronics design software will provide Arcol with unrivalled sales opportunities."

Arcol Products already available from RS Components include the market leading high power HS aluminium housed resistors, the AP725 20W D²PAK packaged resistors, MRA metal film resistors, MSR bare element resistors, RCC carbon composition resistors and ACPP precision passivated chip resistors.

Mike Pritchard continues, "We are continually working with RS Components to ensure they have the stock profile their customers require. Customers looking for stock of our products at RS can use our simple to use “stock locator” which is easy to access from our homepage and allows customers to find available stock of any resistor available via distribution. Powered by the proven netComponents global electronic component database, users may refine their search by geographic region and complete or partial part number."

ARCOL offer one of the widest ranges of resistors available to electronics designers and manufacturers including the market leading HS aluminium housed high power range, the MSR series of bare element resistors, the RWS precision power wirewound SMD resistor family, axial thin film, silicon coated types and precision passivated chip resistors and resistor packs.

Typical applications include traction, snubbers, switched mode power supplies and non-inductive resistors for high frequency and pulse applications,

Resistors easy to access!

ARCOL Resistors now offers customers an online facility to locate and purchase their wide range of resistor products from their global distribution network.

The simple to use “stock locator” is easy to access from Arcol’s homepage and allows customers to find available stock of any resistor available via distribution. Powered by the proven netComponents global electronic component database, users may refine their search by geographic region and complete or partial part number.

Tony Daly, Sales Manager of ARCOL Resistors, comments; “We understand how important it is for our customers to have fast delivery of our resistors from stock and how time consuming it can be to make telephone or email enquiries around a number of distributors to find what they need. Our new, online stock locator will greatly simplify this process as all of our major franchised distributors will make their own stock available to the netComponents search-engine. From now on a single visit to our website should direct our customers immediately to the stock they need.”

ARCOL offer one of the widest ranges of resistors available to electronics designers and manufacturers including the market leading HS aluminium housed high power range, the MSR series of bare element resistors, the RWS precision power wirewound SMD resistor family, axial thin film, silicon coated types and precision passivated chip resistors and resistor packs.

Typical applications include traction, snubbers, switched mode power supplies and non-inductive resistors for high frequency and pulse applications,

Resistors for measurement and control systems!

MSR Bare Element Resistors from ARCOL, have been developed for current sensing and shunt applications in intelligent power systems and instrumentation.

The MSR series feature a special alloy element, copper-clad steel leads and welded construction. Built in stand-offs and standard lead spacings make for simple PCB mounting.

ARCOL MSR Bare Element Resistors offer values from 0.0005Ω to 1Ω, are low inductance (less than 10nH), have a flameproof construction, a TCR of 20ppm/°C and are RoHS Compliant. MSR resistors will operate up to 275°C and have power ratings up to 5W at 85°C.

Tony Daly, Sales Manager at ARCOL, comments; “OEMs increasing need to automate manufacturing and our high power RWS range offer previously unavailable SMD assembly of high power resistors offering time and manufacturing cost savings.”

Resistors provide heat in space probe

Yesterday we talked about Keeping Cool in heated enclosures so we couldn't avoid mentioning this very different application where the opposite is required!

ARCOL Resistors has a great deal of experience of providing products for custom requirements but faced a unique challenge when asked to provide resistors for a space programme.

The THEMIS heliophysics constellation of satellites was commissioned by NASA to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of colour. Discovering what causes auroras to change is intended to provide scientists with important information on how the planet's magnetosphere works and the important Sun-Earth connection. Now in its sixth year in space THEMIS is helping to show how even small variations in the magnetosphere can sometimes cause extreme space weather.

These satellites have proven to be so reliable that NASA has been able to repurpose two already in-orbit spacecraft to extend their useful science mission in a new project known as ARTEMIS (Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon’s Interaction with the Sun). This additional use has removed the need to build and launch new spacecraft, saving NASA tens of millions of dollars.

Arcol were commissioned to provide a highly reliable heat source to protect the sensitive data gathering and processing electronics and proposed their HS range of high power resistors. The resistor design process started in 2007 when a number of the products were tested for out gassing when exposed to 10-6 - 10-9 torr conditions. SSL Berkeley undertook the design confirmation process to ensure that the resistors provided the appropriate thermal range under worst case conditions. From those tested, the ARCOL parts were found to have the lowest out-gassing characteristic. This was due to ARCOL’s unique moulding process producing a highly reliable insulation that ensures the case is completely filled, minimising voiding and imperfections.

Further, there was the requirement to withstand rigorous preparation processes applied from mechanical and electrical characteristics modelling to ultrasonic cleaning with Isopropyl alcohol for installation in the module. It was through this process that the HS type device was tested and selected by the Space Sciences Laboratory at Berkeley for inclusion in the THEMIS module.

ARCOL's HS Series are a range of high quality, high stability high power wire-wound resistors which are packaged in a compact and robust aluminium casing designed for direct heat-sink mounting or panel attachment using a thermal compound to achieve maximum dissipation of heat into the surrounding environment. The resistive element is wound onto a high thermal conductivity ceramic former ground to a close tolerance finish ensuring maximum contact for rapid heat transfer. The element is encapsulated into the aluminium housing by a transfer moulding process which ensures a good humidity seal and a permanent compression fit. The encapsulant is a high temperature moulding compound and the special ARCOL mould tool design ensures accurate concentricity of the element inside the housing ensuring a high level of voltage protection.

Key specifications include; RoHS compliance and manufacture in line with the requirements of mil -18546 and IEC 115. Standard temperature coefficients are typically < 1K 100ppm Std. > 1K 25ppm.

Tony Daly, Sales Manager of ARCOL Resistors, comments; “Arcol has over 60 years of experience in manufacturing resistors and regularly provide custom designs to meet extreme requirements. Our HS series of power resistors are accepted as the industry standard design and footprint manufactured in the UK, very competitively priced and available on low minimum order quantities.”

The HS series of resistors are available in 10 standard power ratings from 10 to 600 watts. Liquid-cooled versions are also available extending the range from 600 to 900 watts. Ohmic resistance values are available over the range R005 to 100K, depending on wattage.

Designed for ease of assembly the HS series offers 7 different termination options, more than any comparable product. A wide range of thermal transfer accessories are available as are customised resistor values and terminations.

ARCOL’s HS series power resistors are optimised for stability, linearity and reliability, making them suitable for many renewable energy, power supply, traction and industrial applications including; inverter/converter, snubber, braking resistor, inrush limiter, balancing resistor, voltage divider, capacitor discharge , cross over, shunt and power supplies.