On New Year’s Day 1968, the programmable logic controller (PLC) was first designed. It has been used ever since to make logic-based decisions in automated industrial processes. Despite their resilience and rugged design, PLC-based control systems can still break down and their failure can lead to costly downtime. This article discusses the top causes of PLC control system failure.

When a PLC control system breaks down, identifying the cause can be tricky. Often, a copy of the PLC software, a laptop, programming lead and a multimeter are the only tools necessary for diagnosing the fault, along with some knowledge of the processes. Sounds straightforward? In many cases it is, but the trap of complacency has a habit of biting. Below is a list of common reasons why PLC control systems fail.

I/O modules and Field Devices

About 80 per cent of PLC failures are a result of field devices, Input/Output (I/O) module failure or power supply issues. Typically, these defects manifest as a sudden process stop or irregularity of performance, because the PLC control system is waiting for a signal to allow it to step through its program sequence. In this situation, the engineer usually determines where the sequence has stopped by interrogating the software ‘on-line’, with the aim of tracing the problem to a specific I/O module and input or output point.

By identifying the I/O point, the engineer can trace the problem to its root cause. This could be a PLC configuration error, tripped circuit breaker, loose terminal block, failure of a 24 VDC supply or issues with wiring. It may be that the I/O module itself needs replacing. This relies on having a readily available supply of replacements, something that is becoming increasingly difficult for legacy systems.

Ground Integrity

Proper grounding is important in protecting both the PLC and maintenance personnel. During maintenance or diagnosis, the engineer can perform a visual check of ground wiring to establish if there has been any damage or if there are any loose connections.

The engineer can test the integrity of the ground with a multimeter. By checking the resistance of the PLC ground terminal to a main earth bonding point in the equipment enclosure, we can establish if this is the root of the problem.

Dealing with Interference

Electromagnetic interference (EMI) and radio frequency interference (RFI) are common in industrial environments that contain a variety of electrical equipment. Companies need to control electrical noise, because it can lead to intermittent faults or unusual behaviour and even PLC failure.

There are many ways to mitigate the risk of downtime caused by electrical noise. A service engineer can recommend ways to minimise noise by relocating sensitive equipment, segregating systems with high power components and adding barriers, grounding, or shielding cable between sensitive equipment.

Network and Communications

Most PLC control systems need to communicate with periphery devices such as Human Machine Interfaces (HMIs). A typical communication medium will consist of an industrial network, which industrial plants increasingly base around industrial Ethernet. A loss of communication between devices will often result in immediate plant downtime.

Engineers can mitigate against communications failures by ensuring the physical network infrastructure is correctly installed and terminated, that network devices are suitable for purpose and firmware patches are regularly installed to maintain reliable and secure operation.

Managing the Risks

By following a best practice routine, companies can minimise the chance of PLC control system failure. Engineers should ensure the environment in which the control system operates is sound. Through systematic inspections, engineers can identify any overheating or electrical noise problems.

Obsolescence management is also important because PLC manufacturers regularly cycle their product ranges. If a component is several years old, it is important to have a readily available replacement. Businesses can manage this internally or by using a third party, such as Boulting Technology, who is able to indicate which areas of a control system are more likely to lead to failure and put a contingency plan in place to mitigate that risk, including sourcing legacy components.

Although it has been around for a long time, the PLC is not invincible. However, with proactive maintenance, environment control and contingency plans, your PLC control system will be there to keep your operations up and running every day of the year, including New Year’s Day.

Source: https://www.automation.com/automation-news/article/inside-the-top-causes-of-plc-control-system-failure

Air conditioning, which includes air cooling, heating, ventilation and disinfection, provides many opportunities for engineers. These specialized technicians are responsible for the safe and efficient installation, maintenance and repair of air conditioning systems, which can be found in a wide range of buildings, such as homes, offices, factories, hospitals and colleges
Engineers work for engineering and contracting firms, as well as for manufacturers of air conditioning systems. As travel from site to site is often an important part of the job, a driver’s licence is invariably essential. A willingness to work nights and weekends may also be necessary. Numerous training providers offer relevant NVQ 2 and 3 courses, which can be studied full-time, part-time or by distance learning. Annual salaries are in the £28,000 to £30,000 range.

Air Conditioning engineers are required to design, install, maintain and repair systems such as ventilation, refrigeration, gas, air conditioning, central heating, among others. These professionals can work at factories, schools, hospitals, offices, and shops installing different types of air conditioning systems according to customer needs in order to maintain temperature and humidity within buildings.

Air Conditioning engineers usually perform many of the following tasks:

• Providing technical information to clients.
• Inspecting air conditioning systems.
• Diagnosing faulty equipment.
• Buying materials.
• Supervising craft workers.

Skills needed

• Having leadership abilities.
• Being practical.
• Having good written and spoken communication skills.
• Being able to work at heights.
• Having interpersonal abilities.
• Being able to meet deadlines.
• Having knowledge about national and European legislation on refrigerants.
• Being aware of safety issues.
• Having good math skills.
• Being able to read technical drawings.

Education

Employers in this industry require Standard grades (1-4 or A*-C) including Science, Math, English, and a technological subject. It is recommended to have a driving licence to work in different places at the same time.

Salaries

In the event of a no-deal Brexit, companies that currently require quotas under the European F-gas phase-down mechanism will need to apply for a UK quota before 30 March 2019.

The European F-gas and ODS regulations for refrigerants will no longer apply in the UK if the UK leaves the EU without a deal. Instead, new UK regulations will transfer most of the requirements of the EU regulations into UK law.

The information on what will happen in the event of a no-deal Brexit is contained in a new guide produced by the Department for Environment, Food and Rural Affairs (DEFRA). Most affected will be those who produce, supply, import, export or use bulk F-gas or ozone-depleting substances (ODS) or manufacture or import equipment containing F-gas or ODS.

If the UK leaves the EU without a deal, EU F-gas and ODS regulations will no longer apply in the UK from 30 March 2019. However, the UK will continue to restrict ODS and use the same HFC phase-down schedule as the EU.

While most of the rules for F-gas and ODS will not change, the UK will have separate quota systems, and the IT systems UK businesses use to manage quotas and report on use will change.

Companies producing, importing or exporting HFCs or ODS, or products containing HFCs or ODS, will need to apply for a UK quota to place them on the UK market and/or an EU quota to place them on the EU market. Those importing or exporting ODS, including to and from the EU, will need to apply for a UK import or export licence.

Scotland, Wales and Northern Ireland have all decided to remain part of a single, UK-wide system during the EU withdrawal implementation period. The withdrawal period is 30 March 2019 to 31 December 2020.

The Environment Agency will administer the systems for the whole of the UK and is to consult on whether to charge regulated businesses to recover costs of running the quota and reporting systems.

Companies will be contacted this month with their reference value and the Environment Agency will publish details of how to use the UK F-gas systems in early 2019.

Source: https://www.coolingpost.com/uk-news/uk-details-f-gas-quotas-in-no-deal-brexit/

Whether you’re looking to sell your home or buy a new one, you need to be aware that an electrical inspection will be part of the process. The findings of this inspection can affect the price you pay or receive for the property.

However, it is still possible to have issues after an inspection has occurred, that’s why it’s essential to be aware of the 5 warning signs regarding home electrics.

1. Shocks

If you get a small electrical shock when you flick a switch, plug in an appliance or turn something on, then you probably have an issue with the wiring or the appliance.

The most common issue in this instance, assuming your hands are dry, is that the ground has become defective. While a small shock can remind you of the power of electricity, this is something you need to get fixed by a professional as quickly as possible.

• Tripping Breakers

If your breaker keeps tripping then you are probably overloading the circuit or have a bad appliance. However, before you check the circuit it’s a good idea to look at the breaker. These can become old and faulty, or you may have a wiring issue inside the fuse box.

If checking your appliances doesn’t throw any light on the situation you’ll need a qualified electrician.

• Sockets Not Working

The most likely cause of a socket not working is loose wiring inside the socket or the socket is starting to break up, preventing the electricity from getting to your appliance.

This can often be accompanied by the small shocks mentioned in warning sign 1.

You’ll need to verify there is power to the socket, this will eliminate the problem being in the wiring and leave you needing to replace the socket. However, you may prefer to get a professional to look at this for you.

• Spark Or Burning Smell

A spark or the smell of burning is another indication that the wires are loose or the socket defective. There is a good chance this will progress to small electrical shocks and a real risk of a fire developing.

The circuit should be shut off until it can be fixed properly.

• Lights Flickering

If your lights are flickering then you may have a loose wire, damaged socket, over-rated bulb, or even too much insulation.

All of these things will lead to a faulty electrical supply or overheating of your light circuit, causing the bulbs to flicker.  This can also be an issue at the other end of the circuit, in your circuit breaker box. You’ll need professional help to verify this.

Purchasing, or even selling, your home is an exciting time. But, you need to take the right steps to ensure the electricity is safe. It won’t just affect your wallet, it can protect you and the new occupants from harm, which is difficult to put a price on.

Source: https://realtybiznews.com/5-warning-signs-of-electrical-wiring-problems/98752908/

Plans for mandatory five-year electrical safety checks in privately rented homes in England have been confirmed by the government.

The move, which requires legislation, means that landlords will be required to call in qualified inspectors to carry out the checks.

The rules will mirror those already in operation in Scotland.

New tenancies will be the first to be checked with existing lettings following later.

No date has been set for the first checks as Parliamentary time is needed to pass the relevant legislation.

Tragic death

The plans come at the end of years of campaigning by consumer and safety groups such as Electrical Safety First.

The government’s confirmation has been announced 10 years after the death of Thirza Whitall who was found dead by her five-year-old daughter Millie at their home in Porthscatho, Cornwall.

The 33-year-old had been running a bath and the inquest into her death was told the property had no earth connection. An electric current made its way through the taps and into the water

Recording an accidental death verdict, Coroner Andrew Cox said it was “inexplicable” there was no law on checking the electrics in rented homes. The inquest heard the cottage had not had a full electrical check since 1981.

Her mother, Jane Andain said: “The tenth anniversary of Thirza’s death has been a very difficult time for the family. What happened to my daughter was a tragedy, but could have easily been avoided if her landlady had made sure the electrics were properly and regularly checked.”

Phil Buckle, chief executive of Electrical Safety First, said the government announcement would go “some way” to ensuring such a tragedy was not repeated.

Minister for Housing and Homelessness Heather Wheeler MP said: “These new measures will reduce the risk of faulty electrical equipment, giving people peace of mind and helping to keep them safe in their homes.

“It will also provide clear guidance to landlords on who they should be hiring to carry out these important electrical safety checks.”

Source: https://www.bbc.co.uk/news/business-47056406

Landlords must ensure mandatory electrical inspections are carried out in private rented accommodation by competent and qualified inspectors under new rules announced by the government.

They could face tough financial penalties if they fail to comply with the new regulation, which is part of the government’s commitment to drive up standards in the sector.

A transitional period will apply in the first two years, where the new rule will affect all new private tenancies in the first year and then extend to all existing private tenancies in the second year.

Properties with an existing electrical installation condition report (EICR) will not be required to replace it for five years from its date.

For new and fully rewired properties, an Electrical Installation Certificate can be presented in place of an EICR provided the date of the next inspection mentioned on the certificate has not elapsed.

New guidance which sets out the minimum level of competence and qualifications necessary for those carrying out the inspections is to be published.

It will provide clear accountability at each stage of the inspection process – of what is required and whose responsibility it is – “but without placing excessive cost and time burdens” on landlords.

Alongside the new guidance, existing “competent person scheme operators” will be invited to set up an electrical inspection and testing scheme which inspectors and testers can choose to join.

Housing and Homelessness Minister Heather Wheeler said: “Everyone has the right to feel safe and secure in their own home. While measures are already in place to crack down on the small minority of landlords who rent out unsafe properties, we need to do more to protect tenants.

“These new measures will reduce the risk of faulty electrical equipment, giving people peace of mind and helping to keep them safe in their homes. It will also provide clear guidance to landlords on who they should be hiring to carry out these important electrical safety checks.”

Councils will also have the authority to impose fines of up to £30,000 on rouge landlords who rent out poor quality properties from 1st June 2019.

Additional Information

Scottish electrotechnical industry trade body SELECT is emphasising its message with a hard-hitting week of nationwide advertising.

On January 24, minister for business, fair work and skills Jamie Hepburn will be hosting a Working Group to further discuss the issue of introducing Protection of Title for electricians.

In the week leading up to this event, SELECT is planning a widespread radio advertising campaign to highlight the need for regulation and to warn of the dangers of allowing unqualified people to carry out electrical work.

Alan Wilson, acting managing director of SELECT, said: “Our latest media activity will keep up the momentum of the campaign for Protection of Title, which has been at the forefront of our work for a number of years and is now gaining more and more support from politicians of all parties and from the industry and the public at large.

“Electrical installations are extremely complex and they underpin modern life. Every year, fires arising from dangerous electrical installations endanger – and sometimes cost – lives and load costs on to insurance companies and emergency services.”

SELECT’s aim is the delivery of the highest standards of professionalism and workmanship. It promotes constant improvement and believes that the industry must ensure basic standards of safety and competence so that customers can rely on any electrician they may employ.

The trade body’s 1,250 member companies account for around 90% of all electrical installation work carried out in Scotland. They have a collective turnover of around £1 billion and provide employment for 15,000 people.

Source: https://www.scottishconstructionnow.com/article/select-runs-radio-campaign-to-reinforce-use-of-qualified-electricians

The certification body Refcom has published a guidance document on the implications of Brexit on the F-gas regulations.

Refcom says the document will clarify the position we are in, and the consequences of certain proposals still being discussed, after the UK leaves the European Union on March 30.

Due to the constantly shifting nature of the debates in parliament, and negotiations in Brussels, the guidance will be reviewed and updated as positions and situations change.

The document can be read and downloaded here.

Source: https://www.coolingpost.com/uk-news/refcom-publishes-f-gas-brexit-guidance/

A cowboy electrician who dangerously rewired a Hartlepool house has been jailed. The unqualified electrician has been has been jailed for 13 months thanks to a successful prosecution from Hartlepool Borough Council’s Trading Standards team.

John Drac, 35, of Rowan Place, Newton Aycliffe, pleaded guilty to fraud and consumer protection related offences after falsely claiming to be a qualified electrician accredited by several trade associations. The court heard how Draco had offered to complete a full rewire of a property for £3,000. When his shoddy work was challenged by the homeowner, he abandoned the job and kept the full sum. Worried by the quality and safety of the work that had been done, the homeowner then contacted Hartlepool Trading Standards. A qualified council electrical engineer carried out a full inspection and immediately ordered it to not be used as it posed a serious risk of fire and electrocution. The resident was forced to pay an alternative trader thousands of pounds to fix the damage Draco had caused. At Durham Crown Court Draco, who chose to trade under the name J and A Electrical Solutions, was sentenced to 13 months imprisonment and confirmed that he had repaid his victim £3,820.

Ian Harrison, Hartlepool Borough Council’s Trading Standards and Licensing Manager, said: “This successful prosecution sends out a strong message that the courts will not tolerate rogue traders conning people out of their hard-earned cash. “These criminals will face lengthy jail terms and hefty fines, and we would encourage anyone who thinks they may have encountered a cowboy builder or rogue trader to report the incident to Hartlepool Trading Standards on 01429 523362 so they can be swiftly brought to justice.”

Source: https://www.hartlepoolmail.co.uk/news/cowboy-electrician-jailed-for-dangerous-work-on-hartlepool-house-1-9526072