A LANDLORD has been fined £20,000 for not testing fire alarms in a block of flats where a major blaze broke out.

Two people were left trapped upstairs during the fire, weeks after the landlord was told the alarm did not work.

This article will take a closer look at the conditions protective devices must meet to protect a conductor against overload.

The primary purpose of a protective device is to protect the circuit from damage, and for such purposes Regulation 433.1.1 requires the operating characteristics of a device protecting a conductor against overload to satisfy the following conditions:

1. I_n ≥ I_b – The rated current or current setting of the protective device (I_n) should not be less than the design current (I_b) of the circuit.
2. I_n ≤ I_z – The rated current or current setting of the protective device (In) should not exceed the lowest of the current-carrying capacities (I_z) of any of the conductors of the circuit.
3. I₂ ≤ 1.45 I_z – The current (I₂) causing effective operation of the protective device should not exceed 1.45 times the lowest current-carrying capacity (I_z) of any of the conductors of the circuit

Condition 1: I_n ≥ I_b

To avoid unwanted operation of the overload protective device when it is carrying the steady-state load current (I_b), condition 1 requires the rated current of the protective device (I_n) to be at least equal to I_b. However, due to the starting characteristics of the load, a higher value of I_n may be necessary for certain loads (Regulation 533.2.1 refers).

In particular, certain types of electrical load such as discharge lighting, AC induction motors and transformers take a much higher current during starting than during normal operation. Consequently, a device protecting such a load must be carefully selected to ensure that it will not be operated by such ‘starting currents’.

As shown in Table 1, circuit-breakers designed to BS EN 60898-1 are classified into three distinct types – B, C, and D – according to the magnitude of current required to achieve automatic disconnection.

Condition 2: I_n ≤ I_z

This condition is intended to give protection under normal load conditions such that the steady state temperature of the conductors will not exceed the maximum admissible value (such as 70^₀C for thermoplastic insulated conductors).

This is achieved by requiring the conductors to have sufficient current carrying capacity (I_z) to carry the rated current of the circuit protective device (l_n).

Condition 3: I₂ ≤ 1.45 I_z

In circumstances when the circuit is subjected to an overload current, this condition is intended to ensure operation of the device within a time suitable to protect the insulation against damage from any high conductor temperatures caused by the overload current.

Small overloads of long duration

Regarding conditions 1 and 2, it is important that the circuit is designed so that small overloads of long duration are unlikely to occur (Regulation 433.1 refers). In other words, care should be taken that the amount of simultaneously operating load connected to the circuit (I_b), and the current rating of the conductors (I_z) and protective device (I_n), are such that there is unlikely to be a prolonged overload current lower than the current causing effective operation of the protective device (I₂).

Meeting the requirement of condition 3

Provided the requirements of conditions 1 and 2 are met, the requirement of condition 3 is deemed to be met where the protective device is a type (gG) fuse to BS 88-2, a fuse to BS 88-3, a circuit breaker to BS EN 60898 or BS EN 60947-2, or an RCBO of any type to BS EN 61009-1 (Regulation 433.1.201 refers).

Where the protective device is a semi-enclosed (rewireable) fuse to BS 3036, the requirement of condition 3 is met where I_n does not exceed 0.725 times the current carrying capacity of the circuit conductors (I_z), provided the requirements of conditions 1 and 2 are also met (Regulation 433.1.202 refers). This is to compensate for the high value of I₂ of a BS 3036 fuse, which can be up to 2 × I_z.

For cables either buried directly in the ground or buried in ducts where current carrying capacity is based on an ambient temperature of 20°C, compliance with condition 3 is afforded where I_n does not exceed 0.9 times I_z, provided the requirements of conditions 1 and 2 are also met. Regulation 433.1.203 refers.

Cable sizing procedures in Appendix 4 of BS 7671

Section 5 of Appendix 4 in BS 7671 lays out the procedure for determining the size of live conductors that will generally give compliance with the requirements of Regulations 433.1.1 to 433.1.203, discussed in this article.

Where overcurrent protective devices other than the fuses and circuit-breakers referred to in Regulations 433.1.201 and 433.1.202 are used, such as a thermal overload protective device in a motor circuit, it will be necessary for the electrical installation designer to refer to the device characteristics in order to ensure compliance with all aspects of Regulation 433.1.1.

Omission of overload protection devices

The omission of an overload protective device is permitted for both general and safety purposes. The installation of an overload protective device may not be needed for the general situations detailed in Regulation 433.3.1.

In addition, Regulation 433.3.3 permits the omission of overload protective devices for circuits supplying current using equipment where disconnection of the device could result in danger or damage. For example, the unexpected disconnection of the supply to the lifting magnet shown in Fig 2 would cause the unintended release of the object without warning.

Where overload protection is omitted provision of an overload alarm should be considered.

Source: https://www.voltimum.co.uk/articles/requirements-protection-against-overload

An investigation by North Lanarkshire Council’s Trading Standards service led to an electrician being convicted of making false claims he was an approved contractor.

The Bellshill man wrongly claimed he was an NICEIC Approved Contractor, a SELECT Approved Contractor and a Building Standards Approved Certifier. He also pled guilty at Hamilton Sheriff Court to running a fraudulent scheme by pretending he was an NICEIC Approved Contractor, authorised to issue NICEIC certificates and reports, resulting in him obtaining money by fraudulent means. The court fined him £675 for breaching the Consumer Protection from Unfair Trading Regulations 2008 and sentenced him to 11 weeks in prison for the running of a fraudulent scheme.

Councillor Michael McPake, convenor of the Infrastructure Committee, said: “I am delighted at the success of this case, which shows the continuing diligence of the council’s trading standards staff who pursue criminal enterprises, protecting consumers and the interests of legitimate trade. “We will continue to take a zero tolerance approach to individuals who rip off residents or businesses within our community.” Trading Standards are reminding landlords and residents to adopt good practices when contracting for works to be carried out on homes: always carry out checks to ensure the tradesperson operates a legitimate business; check any claims to approvals or endorsements with the relevant trade body, online or by telephone; don’t be rushed into a contract. Obtain written quotations from more than one trader before deciding. Ensure you receive all the necessary documentation prior to work commencing, which should include a detailed description of the work to be carried out, the traders’ identity and contact details, the total price and payment terms, duration of the contract and notice of the right to cancel (if applicable).

Source: https://www.motherwelltimes.co.uk/news/crime/rogue-trader-jailed-after-investigation-1-4782013

SELECT, the campaigning body for the electro-technical trade in Scotland, has been updating its members on key points from the newly launched 18th Edition of the IET Wiring Regulations.

SELECT’s Technical Standards Adviser, Bob Cairney, prepared the guide which is available in an online format to assist members to understand the changes contained in these important regulations. The guide will also feature in the next issue of SELECT’s CableTalk magazine.

Bob said: “BS: 7671:2018 (The 18th Edition of the IET Wiring Regulations) contains a number of significant changes which reflect industry best practice.

“We have recently been out on the road to highlight the changes during our recent very successful Scotland-wide Toolbox Talks. These were held a few weeks ago and the presentations were well received by the members who attended”.

A central theme of the regulations concerns improvements to the level of safety provided in new electrical installations and in particular with regard to fire safety. The 18th Edition introduces new devices called arc fault detection devices (AFDD) and these, where installed can provide an additional level of electrical safety from faults which other protective devices cannot detect specifically arcing faults. These are expected to be widely adopted by the industry.

There is also new guidance on types of RCD and arrangement of devices to achieve selectivity between protective devices. Also of interest is informative guidance on energy efficiency.

Darrell Mathews, Managing Director of SELECT, said: “These regulations incorporate the latest in technological developments across our sector and, while they do not come into force until 1 January 2019, we want SELECT members, as ever, to be in pole position.”

Source: http://professional-electrician.com/18th-edition/select-provides-industry-guidance-newly-launched-18th-edition-iet-wiring-regulations/

Soldering, brazing, and welding are all methods of joining two or more pieces of metal and selected other materials. They are also methods used to fill gaps in metal parts.

In welding, the two metals (or thermoplastic) must be similar. For example, copper cannot be welded to steel. Welding uses high temperatures to melt and join two metal parts. A filler metal is often used as well. When properly done, the finished weld is as strong as the surrounding metal. But if the process is not carried out and the welder applies too much heat, it can change the metal’s properties and weaken the weld. There are several different types of welding, including metal inert gas (MIG), arc, electron beam, laser, and stir friction. Welding is also widely used to slice apart large metal structures by melting through them.

Brazing joins two metals by heating and melting a filler (alloy) that bonds to the two pieces of metal and joins them. The filler obviously must have a melting temperature below that of the metal pieces. Brazing can join dissimilar metals such as aluminum, silver, copper, gold, and nickel. Flux is often used during brazing. It is a liquid that promotes wetting, which lets the filler flow over the metal parts to be joined. It also cleans the parts of oxides so that the filler bonds more tightly to the metal parts. In addition, fluxes are used in welding to clean the metal surfaces.

Properly brazed joints can be stronger than the pieces being joined, but are not as strong as welded joints. Brazing also has minimal effects on the two metal parts.

Soldering is a low-temperature analog to brazing. By the American Welding Society’s definition, soldering takes place with fillers (also known as solders) that melt at below 840°F (450°C). Metals that can be soldered include gold, silver, copper, brass, and iron. The filler, called solder, melts. When it solidifies, it is bonded to the metal parts and joins them. The bond is not as strong as brazed joint or welded one. Solder was once made mainly of lead, but environmental concerns are pushing industry to lead-free alternatives.

Flux is used in soldering, just as it is in brazing and welding to clean the metal surfaces and make it easy for the solder to flow over the pieces to be joined.

Soldering is also used to join electrical components. The joint is not necessarily strong or structural, but electrically connects the parts with conductive solder.

Source: https://www.machinedesign.com/fasteners/whats-difference-between-soldering-brazing-and-welding

Technology has made the transition inevitable. The ability to enhance industrial and process automation efficiency, through the application of real-time enterprise computing, cloud applications, and IoT devices, has never been more clear. Those industrial and process automation suppliers that embrace these shifts in technology and system architecture will be winners. But those suppliers should expect new challenges in the new environment. There are likely to be a number of new suppliers in this environment with unbundled new architectures, analogous to the what was seen in the advent of the computer industry with PCs and open software. This complicates investment decisions for industrial and process automation system users – while the transitions can be challenging, too long of a delay could make you noncompetitive with the other manufacturers in your industry.  But why do you have to face this future alone? Such a future would logically seem to demand cooperation between industrial automation organizations and suppliers with enterprise computing and the new IoT industry.  

The Wild Card for Industrial Automation –  The Computer & IoT Industry

While such investments can be a gamble, the cards are laying in the automation industry’s favor. A flood of new technology and open source application tools are lowering cost and improving ease of use, while accelerating the adoption of IoT in industrial automation. This is enabling a burgeoning community in enterprise computing to perform industrial and process automation middleware software functions more effectively.   Cloud computing from names like Amazon Web Services, Microsoft Azure, etc. are providing platforms that are more efficient means to accomplish historians, analytics, and advanced optimization. Further, the IoT devices that already exist, for a range of non-industrial applications, in many cases satisfy the same environmental and performance requirements needed in industrial and process automation.

Why Are Traditional Vendors Resistant to Change?

While such investments can be a gamble, the cards are laying in the automation industry’s favor. A flood of new technology and open source application tools are lowering cost and improving ease of use, while accelerating the adoption of IoT in industrial automation. This is enabling a burgeoning community in enterprise computing to perform industrial and process automation middleware software functions more effectively.   Cloud computing from names like Amazon Web Services, Microsoft Azure, etc. are providing platforms that are more efficient means to accomplish historians, analytics, and advanced optimization. Further, the IoT devices that already exist, for a range of non-industrial applications, in many cases satisfy the same environmental and performance requirements needed in industrial and process automation.

In the book, Innovation: The Attacker’s Advantage, by Richard N. Foster covering the history of industry change, the key conclusion discusses two types of companies: Attackers try to make money by changing the order of things and Defenders protect their existing cash flows extracted from customers.  In today’s automation industry, these Defenders are some of the established industrial automation suppliers that are not buying into the technology industry open systems that have led to great advances.

A Clear Path Forward?

It would seem that the way forward for the industry is clear. Open source multivendor interoperability – including peer to peer seamless integration between multivendor controllers in a single application platform – are accelerating the industrial automation industry. If the industrial automation vendors don’t work together to make this happen, the computer and IoT community will.  Plain and simple.

The influx of new technologies has made industrial automation revolution inevitable. The Industry 4.0 vision of ‘flexible, make-to-order manufacturing’ is just one example of what is being achieved leveraging these technologies. The competition is already building. Manufacturers in developed countries are increasingly faced with competitors, from other parts the world, who are embracing Industrie 4.0 and other new architectures, and reaping the fruits.

Yet this is where there is opportunity for the traditional suppliers. These rapid advances have created not only value, but also an ‘IIoT Wild West’, which could see an increase in industrial supplier infighting to displace traditional automation and control suppliers. If industrial and process automation organizations come together, they can set the standards that allow for mutual growth and enhanced productivity for all. Whatever they do, IoT solutions will continue to proliferate for sensing, control, and computing in edge devices. These devices can increasingly be seen in highways, medical, smart cities and other applications that meet requirements for a wide range of industrial applications.  With the rise of enterprise computing, and increasing absorption of middleware industrial software functions, the external IoT standards could become the de facto industrial automation standards. With or without the input of traditional vendors.

Source: https://www.automation.com/portals/factory-discrete-automation/programmable-logic-controller-plc/who-will-set-future-industrial-automation-standards

Type AC residual current protection has been applied in UK domestic premises, with little consideration for the nature of appliances and loads connected downstream of the RCD. The impact of increased leakage currents can result in unwanted tripping, which results in other safety complications – loss of lighting and supplies for essential equipment. The 18th Edition addresses these issues and the selection of Types of RCD as applicable to the revised regulations.

Regulation 531.3.2 deals with unwanted tripping and the requirements for reliable performance. Regulation 531.3.3 covers the selection of different Types of RCD, based on the type of residual current and applies to all installations.

Why should we improve safety in Electrical Installations?

Electrical Safety First highlight that far greater demands are placed on domestic electrical installations than at any time, with more electrical appliances per head and increased complexity leading to increased risk of electrical accidents…” Government statistics show that electricity causes more than 20,000 fires a year – almost half of all accidental UK house fires. Each year, about 70 people are killed and 350,000 are seriously injured due to an electrical accident in the home”. In their words…” It’s easy to make an electrical circuit work – it’s far harder to make the circuit work safely “

RCD selection: What the 18th Edition Regulations say

Regulation 531.3 (formally 531.2) covers the selection of RCDs for fault protection by automatic disconnection of the supply. There are several changes in this section giving more detailed requirements and advise on selection of RCDs to improve the quality and safety of domestic installations.

531.3.2 Unwanted tripping

LED lighting, PCs, TV power supplies i.e. any equipment containing capacitors (just about everything these days) produce higher leakage currents than conventional loads we had in our old homes. Customers should be advised of the possibility of unwanted tripping, where too many appliances are connected downstream of one RCD. Examples are given in Table 1 below.

Allow for the reliable provision of lighting circuits in all installations and any medical equipment for home treatment/diagnostics, stair lifts etc. (see See 314 Division of Installation). Domestic Lighting Circuits must now incorporate RCD protection <30 mA – see Regulation 411.3.4.

RCD protected circuits: Consider any earth leakage current likely to occur in normal operation, to reduce the chance of unwanted tripping – see comments page 2.

(i) The sum of the leakage currents shall not exceed 30% of the RCD residual current.

Note 2 Reminds us that RCDs are designed to trip if the residual current is > 50% IΔn

(ii) Short time-delayed* transient resistant 30 mA RCDs with 5 x IΔn <40 ms characteristic can be used to reduce unwanted tripping associated with capacitors charging in power supplies.

*Not to be confused with Selective / Timed delay RCDs which are not suitable for 30 mA applications.

Equipment with leakage currents > 3.5 < 10 mA must be permanently connected see 543.7.1.201.

531.3.3 Types of RCD

This Regulation specifies the different Types of RCD based on their ability to deal with various types of residual current.

The appropriate RCD shall be selected from the following Type: AC, A, F or B, See Table 2 below for a summary of the RCD characteristics given in 531.3.3.

Note: Type EV is related to Reg. 722.531.2.101 for car charging installations, not for inclusion in Domestic Consumer units.

Appliances including certain types of washing machine, induction hobs, LED lighting, power supplies for TV, PC and AV equipment, speed control on pumps etc. can produce residual currents that are not compatible with type AC RCDs.

Incorporating these requirements into consumer units

Most equipment using single phase SWM power supplies e.g. PCs, TVs, game consoles, LED lamps should be suitable for use with Type A RCDs. Some equipment mainly related to kitchens and or utility rooms is designed for connection to circuits protected by Type F RCDs. These appliances are becoming more common as older appliances are replaced with energy efficient ones. This is likely to have a greater impact on New Builds, where appliances are supplied as part of the fixtures and fittings. The House Builder is also responsible for the electrical specification and installation certificates for each property. What are the risks if you use Type A instead of Type F; residual currents generated by the equipment <1kHz cannot be detected and they may also result in the RCD overheating / non-tripping for 50Hz residual currents.

For lighting circuits incorporating LED lamps, consider the individual LED driver’s inrush current and leakage current. The high transient currents that flow when the LED drivers are powered up (typically 50 -80 x Lamp current), may cause unwanted tripping if there are too many lamps on 1 circuit (standard RCDs – maximum 250A 8/20μs). If this is likely to be an issue, restrict the number of lamps per circuit or use transient resistant RCD such as Type AKV or Type F – see table 2. The Leakage current is harder to determine as it will be linked to the type of fitting, type of lamp and the location e.g. in a bathroom or other humid environments. These two areas require practical experience and advice from the LED lamp manufacturers, to help installers design reliable lighting installations, when associated with 30mA RCD protected circuits.

Design for safe and reliable operation

In a modern installation, it is unlikely that Type AC RCDs can be used safely, unless the circuit is restricted to the use of general purpose equipment, such as resistive heating and lighting loads. The example consumer unit contains a single module Type A RCBO for lighting circuit with room for other RCBOs, alarm circuits etc. Type F RCCB protected circuits for kitchens, utility rooms, plus any other circuits and Type A RCCB for circuits supplying family rooms and bedrooms, in line with the requirements of the 18th Edition Regulations.

Source: https://www.voltimum.co.uk/articles/consumer-units-and-rcds-18th-edition-bs

This article reviews the recommendations of the emergency lighting standard BS 5266-1: 2016 for the provision of emergency lighting in escape routes, open areas and other locations.

As a result of a number of legislative requirements such as those relating to health & safety, fire and building regulations some form of emergency lighting will normally be required in most, if not all, non-domestic premises.

Defined escape routes

The defined emergency escape routes within buildings should be provided with at least the minimum levels of illumination recommended by clause 5.2.5 of BS 5266-1. For escape routes up to 2 m in width, the horizontal illuminance along the centre line (at floor level) should be at least 1 lx. In addition, clause 4.2.1 of BS EN 1838 requires that the central band of the escape route (consisting of not less than half the width of the route) should be illuminated to at least 50 % of that value. Wider routes should be treated as a number of 2 m wide strips, or open area (anti-panic) lighting should be provided.

It should be recognised that in earlier editions of BS 5266-1, a reduced level of illumination of 0.2 lx was permitted in escape routes, provided they were kept unobstructed at all times. However, in practice, ensuring corridors and stairways (that formed part of an escape route) were clear and hazard free at all times proved difficult to manage, mainly because items such as photocopiers, display cabinets, and seating were often located in such locations. As a result, where such locations are found to have a reduced level of emergency lighting it must be confirmed that this provision remains suitable for the application.

Some occupants, such as the elderly or those with impaired vision, will take longer to perceive objects and adapt to changes of illuminance. Therefore, the illuminance provided along the escape route(s) may need to be higher than the minimum value specified. (BRE Information Paper 9/97 [28] identifies conditions that benefit from a minimum illuminance of 3 lx on the centre line of the escape route, clause 5.2 refers).

Open areas and rooms

The objective of open area (anti-panic) lighting is to provide a sufficient level of illumination so that occupants can feel safe and move towards a place of safety when the supply to the normal lighting fails. Excluding a 0.5 m strip around the perimeter of the area, clause 5.2.6 recommends that a minimum illuminance of 0.5 lx is provided at the floor surface in the following open areas:

• rooms greater than 60 m² in floor area
• areas of any size with an escape route passing through them
• any areas that the site risk assessment has identified as requiring emergency illumination; for example, a school laboratory where students handling acids would be at risk if they were in total darkness.

The following example illustrates the recommendations of BS 5266-1 for the provision of emergency lighting in open areas and rooms.

Typical factors for consideration in a risk assessment include underground or windowless areas, high levels of occupancy, whether an escape route passes through the area or if there is a need to switch off equipment before leaving.

For the designated escape routes shown, luminaires will need to be provided at all points of emphasis in accordance with clause 5.2.8, such as, for example, at changes of direction, exits and outside the building to a place of safety.

High-risk task area lighting

Greater levels of emergency illumination may be required in areas of particular risk to allow for the safe shut-down of potentially dangerous processes or activities. Clause 5.2.7 recommends that an emergency illumination of not less than 10% of the normal lighting (average value) is provided at the relevant point of the location of the risk. However, depending on the activity higher values may be needed. Requirements for high-risk task area lighting are specified in BS EN 1838.

In premises where the occupants are not intended to be evacuated immediately, ‘emergency safety lighting‘ should be provided in accordance with clause 5.3.

The NICEIC and ELECSA snags and solutions publication; Emergency Lighting Part 4 provides guidance on the design, installation and inspection and testing of emergency lighting systems.

Source: https://www.voltimum.co.uk/articles/what-are-recommendations-emergency

ACRIB has called for more support from Government to improve training take up and increase skills levels in the air conditioning and refrigeration industry.

ACRIB, the Air Conditioning & Refrigeration Industry Board, was reacting to the government’s recent response to the Environmental Audit Committee report on the UK’s progress in reducing F-gas emissions.

Echoing the recent reaction of manufacturers’ group FETA, ACRIB welcomed the Government’s willingness to work with industry on training but said it believes this “lacks teeth” and called for mandatory qualifications and the establishment of a national register.

“One of the key recommendations of the EAC report was that government work more closely with industry to deliver solutions to ensure effective implementation of the F-gas regulation and reduction of emissions,” explained ACRIB chairman, Graeme Fox of BESA. “One of the critical issues for our industry is training in low GWP alternatives, and this is an issue that ACRIB has been swift to address. However more support is needed from government to improve training take up and increase skills levels in the industry.”

With breaches of the F-gas regulations and illegal refrigerants seemingly becoming an increasing problem in the UK, ACRIB, like FETA, was critical of the government’s rejection of calls for increased resources for DEFRA and the Environment Agency (EA).

In a statement, it said: “ACRIB would, of course, like to see both departments given greater prioritisation for resources by Central Government. In the interim, we will continue to highlight blatant infringements of regulations, particularly by on-line retailers.”

ACRIS is the umbrella organisation representing trade associations and professional institutes operating in the RACHP sector.

Source: https://www.coolingpost.com/uk-news/governments-f-gas-stance-lacks-teeth/