The Technique Learning Solutions summer sale will end this coming Friday (the 18th of August, 2017). Customers still have 3 days to take advantage of this offer and make savings of up to £424.20.
Use code ‘SUMMER10’ at the checkout to activate the discount.
(offer only available when paying for the course in full. Not available for ELCAS bookings, Terms and Conditions apply)
A refrigerant gas used to cool some of the island’s industrial spaces, commercial spaces and homes is being phased out.
The move is in line with the Montreal Protocol of 1987, designed to reduce ozone depletion, and is likely to affect local supplies, according to the Department of Environment and Natural Resources.
“Those with heating, ventilation and air-conditioning (HVAC) systems which use R-22 may be best served by changing to a non-ozone-depleting gas in the near future,” a statement said.
“Industry stakeholders and those with permits to handle refrigerant gases have been aware for some time that hydrochlorofluocarbons (HCFCs) would be phased out internationally, including a refrigerant gas commonly used in older HVAC systems in Bermuda, called R-22.”
The statement added that manufacturing has also been affected, with a tightening of requirements necessary before the gases can be exported.
“In addition, an amendment to the original protocol has not been extended from the UK to Bermuda and other Overseas Territories.
“The OTs are required to ratify the amendments before this extension from the UK can be provided. As a result, the original manufacturers of HCFCs cannot send gases to Bermuda until this extension process has been completed.”
While HCFCs can still be bought from other suppliers after approval by the Environmental Authority, this is expected to cost more.
“The department is currently working to complete this ratification of the amendment to the original protocol so it can be extended from the UK,” the statement added.
“In the interim, the department advises that consumers installing new HVAC systems ask for non-ozone-depleting refrigerant gases and encourage existing customers who have R-22 based systems to consider changing them to non-ozone-depleting refrigerant gases.
“It is also important to note that there are some compliant refrigerant gases that can be substituted in existing R-22 systems without the need to replace blowers, condensers and associated pipework.
“An HVAC supplier’s service personnel should be able to advise on any compatibility issues.”
To make it easier to talk about automation, especially when done in a factory setting (industrial automation), engineers and plant managers have divided the topic up into three categories.
Automation takes mechanization one step further. While mechanization replaces manual labor with machines, automation replaces human guidance with controls hardware, computers, and programming (PCs, PLCs, and PACs, for example), together with some help from communication devices and hardware.
But automation systems can be complex, with a large number of devices working in synchronization. To make it easier to talk about automation, especially when done in a factory setting (industrial automation), engineers and plant managers have divided the topic up into three categories: field-level automation, control-level automation, and enterprise or information-level automation. Here are short explanations of each:
It is the lowest level of the automation hierarchy and consists of field devices such as sensors and actuators. Sensors, the eyes and ears of automation, collect data on temperature, pressure, speeds, feeds, and so on, convert it to electrical signals, and relay it up to the next level. The main task of these field devices is to transfer data on processes and machines for monitoring and analysis.
It also includes the actuators, which are controlled by the next level through electrical or pneumatic signals, converting them into actions. Actuators are similar to the body’s muscles, which are the only way humans can interact with their environments. Actuators turn valves, relays, motors, pumps, and other devices on or off, or adjust their outputs to control the processes.
This level consists of various automation controllers such as CNC machines that gather process parameters from various sensors. The automatic controllers then drive the actuators based on the processed sensor signals and the program or control technique.
Programmable logic controllers (PLCs) are the most widely used and durable industrial controllers that can deliver automatic control functions based on sensor inputs. They consist of various modules such as the CPU, analog and digital I/Os, and communication modules. It lets technicians program control functions or strategies that carry out certain automatic operation on process.
In this level, automatic devices and monitoring systems facilitate the control and adjustment functions. These include Human Machine Interfaces (HMI), Distribution Control Systems (DCS), and supervisory control and data acquisition (SCADA) devices for monitoring various parameters, setting production targets, historical archiving, and setting machine start and shutdown.
This top level of industrial automation, which is also called Information-level automation, manages the whole automation system. The level handles production planning, customer and market analysis, and orders and sales. So it deals more with commercial activities and less with technical aspects.
Industrial communication networks tie all these levels together, sending data from one level to the other. These communication networks can be different form level to level. These networks include RS485, CAN, DeviceNet, Foundation Field bus, and Profibus.
With this hierarchy in place, there is a continuous flow of information from high level to low level and vice-versa. As data goes up, information gets aggregated, and as data goes down, it provides detailed information about the process.
Types of Industrial Automation Systems
There are three general types of automation systems:
Fixed or Hard Automation performs fixed and repetitive operations to achieve high production rates. It uses special-purpose or dedicated equipment to automate a fixed sequence of assembling and processing operations. Once put in place, it is relatively hard to change or vary the what the system builds or creates. Therefore, while it is inflexible in providing product variety, it increases the efficiency with higher production rate and reduces unit cost.
Programmable Automation consists of assembling and processing operations that can be changed by modifying the overall control program in the automated equipment. It is best suited for a batch production process where product volume is medium to high. It is still difficult to change and reconfigure the system for a new product or sequence of operations. Therefore, new products or reconfiguring the sequence of operations requires a long setup.
Flexible or Soft Automation systems provide the automatic control equipment with the flexibility to change the product design. These changes can be performed quickly through the commands given in the form of codes to various machines by technicians. It lets manufacturers turn out several products on the same production line. Some examples of this type of automation equipment include automatic guided vehicles and multipurpose CNC machines.
Benefits of Automation
There are five basic reasons for automating a process or an entire assembly/production line:
To increase productivity. Automating a factory or manufacturing process speeds production by better controlling it, which can significantly slash assembly time per product. Therefore, for a given labor input, automation generates more output.
To lower operational costs. Integrating various industrial processes with automated machineries minimizes cycle times and effort and therefore lowers the need for manual labor. This cuts labor costs. Automated equipment properly used should also cut material costs. of human labor gets reduced. Thus, the investment on employees has been saved with automation.
To improve product quality. Automation removes human involvement from production, so the possibility of human errors should also be eliminated. Uniformity and product quality can be maintained with automation by adaptively controlling and monitoring the industrial processes in all stages from product inception to finished product.
To reduce routine checks. Automation reduces the need to manually check various process parameters. Industrial processes can automatically adjust process variables to set or target values using closed-loop control.
To improve safety. Industrial automation substitutes machinery for personnel in hazardous or risky working conditions. Traditionally, industrial robots and robotic devices serve in these environments.
The 18th Edition of the Wiring Regulations, aka BS 7671:2018, is now available as a Draft for Public Comment on the British Standards Institution’s website. The draft is an opportunity to see the proposed content of the revised wiring regulations ahead of publication and to have your say about the changes.
One of the proposals is the addition of a new section, Part 8. This has been introduced to reduce the energy consumption of electrical installations. It is based on the International Electrical Commission’s new standard IEC 60364-8-1 Low Voltage electrical installations Part 8-1 Energy Efficiency.
The new section covers several energy efficiency areas including limiting the voltage drop within an installation in order to reduce power losses in the wiring system which are evident as heat.
We welcome any initiatives that are designed to improve the safety or efficiency of electrical installations: we know that the simplest way to bring down power losses is to reduce the voltage drop and to use a cable with a larger cross-sectional area of conductor.
The draft document states that the decision on whether or not to increase the conductor size ‘shall be made by assessing the savings within a time scale against the additional cost due to this over-sizing’. In other words, the reduction in power loss from increasing the cable’s conductivity should be higher than the additional cost of the cable over the lifetime of the installation.
If, for example, a long run of cable is supplying a constant high load it may well be more cost effective for the cross-sectional area of the cable to be increased in order to reduce power losses. For that reason, the use of the term ‘over-sized’ is not appropriate in this instance. If it is more cost effective over the lifetime of an electrical installation to use a copper conductor with higher conductivity then it is not ‘over-sized’ but optimally sized. A more appropriate term would be ‘upsized’.
There will, of course, be an increased cost for the additional copper in larger conductor cables when compared with traditional ‘minimum sized’ solutions, as well as accessories and supports, but aside from that installation costs will be broadly the same for new build installations, assuming the same sized conduit or cable tray are still appropriate for the larger diameter cables.
As a manufacturer, Prysmian Group has always supported the view that quality should be our aspiration rather than lowest price. This is reflected in the rigorous testing of all of our products and our refusal to compromise where safety or long-term performance is at stake, which is why we feel we can justify the claim that professionals choose Prysmian. With this in mind, it is perhaps not surprising that we would suggest that, in addition to reducing power losses, there are some other benefits to be had from cable ‘upsizing’.
These would include increasing the cable’s capacity, which may help future-proof the system and reducing heat emissions from the wiring from harmonic currents. And, because an ‘upsized’ cable will generate less heat, there will also be energy savings, albeit minor ones, from reducing the speed of cooling fans and perhaps even the size of building’s air conditioning system.
Other changes proposed in the Draft 18th Edition of the Wiring Regulations include:
- Redrafting the section relating to protection against transient over-voltages of atmospheric origin, such as lightning strikes, to ensure protection is in place mitigating against the risk of fire caused by arc fault currents in electrical equipment and
- Extending the scope of the section on embedded electric heating systems for indoor and outdoor surface heating, such as those for de-icing or frost protection.
The Wiring Regulations apply to the design, erection and verification of electrical installations in commercial, residential, public and industrial premises along with infrastructure and even caravans.
The Wiring Regulations are written by industry experts whose objective is to focus on achieving the best and safest electrical installations. The panel aims to represent the industry, but recognize that the industry is actually made up of the thousands of professionals who carry out installations every day. Therefore, the Regulations are open to comment and we would urge everyone who will be affected to take a look at the draft. There is an opportunity to have your say – the draft is open for comment until 23 August 2017.
The Environment Agency (EA) could receive increased powers of prosecution following concerns of installations and refrigerant purchases by non-F-gas-certified companies.
Concerns over qualification and competence checks and a rise in non-compliant ID cards were topics raised by F-gas certification body Refcom during a recent meeting on key industry issues with representatives from DEFRA.
While suppliers and distributors have a legal responsibility to check the operative purchasing gases has original F-gas certificates or an ACRIB SKILLcard, Refcom says it is worried about the development of alternative ID methods claiming to be acceptable representation of a company’s F-gas certification. Refcom maintains that DEFRA shares those concerns.
“In other areas, there are still reported cases of split systems being bought by non-qualified companies and installed illegally, often badly, so that legitimate Refcom registered companies have to go in after the installation and put right the many deficiencies in install quality,” the group claims on its website.
Article 11(5) of the regulation aims to stop the sale of split systems that would then be installed by non-certified companies or personnel. End users are allowed to buy a pre-charged split system but they must provide evidence of who will carry out the installation and their registration number for the authorities to check.
“It is a legal requirement that the seller check this evidence,” says Refcom, “although it is clear this is not always happening.”
As a result of its revelations, Refcom maintains that new legislation is now being drafted to give the EA increased powers of prosecution against non-conforming companies and end users under increased domestic civil penalty laws.
How long have you been with the company?
CA: I have been with TLS for 1 year & 5 months. I started in January 2016 after I was interviewed and accepted as a new member of the team. My first induction day was 21st December 2015.
What is your role within the business?
CA: I manage day-to-day enquiries, whether these are emails, live chats or telephone calls. I organise practical assessments & written exams for those who complete a course with TLS, and ensure that certificates are posted to the correct addresses. I also organise certain parts of the company’s social media, such as Facebook posts and the Blog feature on our website.
Tell us an interesting fact about you?
CA: Black Belt instructor in Jiu-Jitsu, known as ‘Sensei’
What do you like doing away from work?
CA: I enjoy any types of sports with friends, helping run my Jiu-Jitsu club & training, holidays away in the caravan, & going to the cinema. I’m also a big follower of F1 & tennis.
If you could have 5 celebrities round for dinner, who would they be?
Ed Sheeran, James Corden, Lewis Hamilton, Camila Cabello, Harrison Ford.
What are your favourite 3 films?
What are your favourite tv shows?
Game of Thrones
The Walking Dead
You’re hosting a festival, you can choose 5 headliners (dead or alive), who do you chose?
The Weeknd, Linkin Park, Maroon 5, Zara Larsson, Ed Sheeran
What’s your favourite thing about working for Technique Learning Solutions?
The friendly atmosphere in the workplace.
What is the difference between discrimination and backup protection? This is a question that has troubled some.
The fact that, ‘selectivity’ is now the preferred word for discrimination and that back-up protection is also called, ‘cascading’ doesn’t help.
Add related terms like, ‘pre-arcing energy’ and ‘energy let-through’ and it’s not difficult to understand the potential for confusion.
Co-ordination of protective devices
Series-connected protective devices, as shown in Fig. 1, are normally co-ordinated to prevent danger and to ensure proper functioning of the installation. (The exception is where disconnection of the supply is not permitted, as in the case of life-support systems.) Regulation 536.1 of BS 7671 indicates that the word, ‘coordination’ generally means consideration of selectivity and /or any necessary back-up protection. Clearly then, selectivity and back-up protection are not the same and we will now consider each one.
Discrimination (Selectivity), is defined in Part 2 Definitions as, ‘Ability of a protective device to operate in preference to another protective device in series’.
The purpose of selectivity is to isolate a part of an electrical installation with a fault condition from the rest of the installation such that only the protective device located immediately on the supply side of the fault operates to disconnect the supply.
The traditional means of achieving selectivity are by current or by time.
Current selectivity utilises overload or fault current while time selectivity uses devices with different trip time settings.
Current selectivity is the more common method and the one which we will deal with here.
There has frequently been discussion within the industry about which devices will discriminate with which other devices and at which level of fault current.
Regulation 536.2 requires that the manufacturer’s instructions be taken into account in the design of selectivity between overcurrent protective devices.
For selectivity between fuses, the rule of thumb is that an upstream fuse will discriminate with a downstream fuse of half its rating.
For selectivity between circuit- breakers, the 2 to 1 ratio is generally valid for the thermal trip section of the curve.
Selectivity is a basic requirement for a reliable and safe installation.
The pre-arcing energy and the energy let-though
It will be appreciated that protective devices do not operate instantaneously and, after a device starts to open, some fault current will continue to flow through it for a certain time. To explain selectivity further, we must introduce two terms – the pre-arcing energy and the energy let-through.
Both terms are important characteristics in the design of selectivity (and backup protection systems) and both can be seen in Fig. 2.
At point A (time t1), the contacts start to open and arcing begins
At point B (time t 2), disconnection begins
At point C (time t 3), the fault has cleared
Area 0B t 2 portrays the pre-arcing energy
Area 0B t 3 represents the total energy let-through
The pre-arcing energy I2t is the energy required to make a fuse element start to melt or contacts begin to open. (The term, ‘melting’ only applies to fuses but all overcurrent protective devices develop an arc when their circuit contacts open. Thus, the term ‘pre-arcing’ applies generally to overcurrent protective devices.) The total energy let-through I 2t is the total energy which is let through by the device until the arc is quenched. (The unit of I2t is amps squared per second.)
Selectivity is achieved when the pre-arcing I 2t of the upstream device is less than the total energy let-through I 2t of the downstream device.
In plain English – for fuse to fuse discrimination – this means that the smaller fuse must complete its operation before the larger fuse reaches its melting point.
Selectivity between fuses is shown in Fig. 3.
In terms of cable protection, the I²t must be less than or equal to K²S² which is the ‘energy withstand’ of the cable. (See Regulation 434.5.2 for an explanation of these terms.)
BS 7671 requires that the rated breaking capacity of each protective device must be not less than the maximum prospective short-circuit current or earth fault current at the point at which the device is installed – unless backup protection is provided.
The basic principle of back-up protection is contained in two regulations:
- Regulation 434.5.1, which deals with the characteristics of fault protective devices, and,
- Regulation 536.1, which concerns the coordination of protective devices
The term, ‘energy let-through’ is mentioned in both of these regulations in the context of backup protection.
Back-up protection is provided where the characteristics of the devices are suitably co-ordinated such that the energy let-through (I 2t) of the device on the upstream side (ie. the supply side) does not exceed that which can be withstood, without damage, by the device(s) on the downstream side (that is, the load side).
Back-up protection permits the installation of downstream devices (and cables and enclosures) which have a short-circuit breaking capacity lower than the prospective short-circuit current where they are installed, giving substantial savings.
Perhaps back-up protection is best illustrated by the cartridge fuses (BS 1361 or BS 88-3) in domestic cut-outs.
Protective devices in a consumer unit, such as circuit-breakers and RCBOs with a rated short-circuit capacity of 6kA or 10kA and rewireable fuses to BS 3036 with a rated short-circuit capacity of 1 – 4 kA are ‘backed up’ by the cartridge fuse in the cut-out.
Where backup protection is provided, it must be in accordance with the manufacturer’s information.
The design of selectivity and backup protection are greatly assisted by studying the graphs in Appendix 3 of BS 7671 and /or seeking guidance from the relevant manufacturer.
While it is hoped that this article has proved helpful, it should be considered only as an introduction to these topics.
The Technique Learning Solutions summer sale will end on Friday the 18th of August, 2017. Customers still have 2 and a half weeks to take advantage of this offer and make savings of up to £424.20.
Use code ‘SUMMER10’ at the checkout to activate the discount.
(offer only available when paying for the course in full. Not available for ELCAS bookings, Terms and Conditions apply)
UK: F-gas registration body Refcom is urging companies to renew their certification in a timely manner, amid concerns that some companies risk trading illegally.
Certificates require renewal every three years, so with the bulk of the companies who are registered and compliant attaining full certification by 2011 this year represents a peak renewal period.
While online renewal is a relatively quick and simple process, it can be delayed if companies do not have the necessary up to date paperwork – particularly latest engineers’ certificates.
Refcom says it is working hard to process renewals for registered members as quickly as possible, but any delays could see companies being without a valid F-gas certificate and trading illegally.
Without a valid certificate it might be impossible for companies to obtain supplies of gas and equipment and a company’s registration with its own clients as an approved installer or service provider could be affected. In addition, it could even result in prosecution if an inspection finds a company wasn’t complying with the law at the time of work being carried out.
Concerned that some companies have been slow to renew despite sending out regular email reminders, Refcom recommends that the renewals process is carried out as soon as possible. It even advises renewing ahead of the expiry date as the new certificate will only commence from the date the old one expires.
Daikin’s R-407H has been submitted for EPA SNAP approval as a replacement for R-22, R-404A, and R-507A. Daikin America Inc., a subsidiary of Daikin Industries, announced the availability of R-407H refrigerant for research and development, and test marketing samples in the United States.
Samples are applicable to OEM systems and R-404A and R-22 retrofits. Contractors and distributors should reach out to equipment manufacturers for specific guidance. This follows the official product launch of Daikin R-407H on March 8.
Daikin R-407H has been submitted for approval to the EPA SNAP Program as a replacement for the legacy ozone-depleting refrigerant R-22, and high global warming potential refrigerants such as R-404A and R-507A, which are widely used today for supermarket, warehouse, and marine vessel refrigeration equipment.
“Due to increased regulations, high GWP and ozone-depleting refrigerants, such as R-22, are being phased out,” stated Jim McAliney, executive vice president of sales and marketing, Daikin America. “Daikin’s 407H was developed to comply to global regulations while allowing for simple and economical retrofits.”
Daikin’s nonozone-depleting, GWP 1495, non-flammable refrigerant R-407H compares favourably to R-404A, which is commonly used today. You can view a comparison of the two here. R-407H has been classified by ASHRAE as safety group A1, and is compatible with common POE oils. Performance details, test results, case studies and compatibility information are available upon request.