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RoHS Examined

RoHS Compliant SymbolThe Restriction of Hazardous Substances Directive 2002/95/EC, (RoHS), short for Directive on the Restriction of the use of certain Hazardous Substances in electrical and electronic equipment, was adopted in February 2003 by the European Union. 

China RoHS (Restriction of Hazardous Substances), officially known as Administrative Measure on the Control of Pollution Caused by Electronic Information Products is a Chinese Government regulation to control the same materials as RoHS 2. Unlike EU RoHS 2 Directive, however, this does not allow any technology exemptions. This article will be concerned with EU RoHS.

This RoHS 1 directive took effect on 1 July 2006, and was required to be enforced and become law in each member state. This directive restricts (with exceptions) the use of six hazardous materials in the manufacture of various types of electronic and electrical equipment. It is closely linked with the Waste Electrical and Electronic Equipment Directive (WEEE) 2002/96/EC which sets collection, recycling and recovery targets for electrical goods and is part of a legislative initiative to solve the problem of huge amounts of toxic electronic waste.

The RoHS 2 directive (2011/65/EU) was an evolution of the original directive and became law on 21 July 2011 and took effect 2 January 2013. It addresses the same substances as the original directive while improving regulatory conditions and legal clarity. The CE logo indicated compliance and RoHS 2 declaration of conformity was now detailed.

The RoHS 3 directive (2015/863) adds four additional substances. Slated for adoption and publishing by EU governments internally by the end of 2016, the additional four substances shall be applied by 22 July 2019 except where exemptions permit.
The restricted substances are;

1.    Lead (Pb)
2.    Mercury (Hg)
3.    Cadmium (Cd)
4.    Hexavalent chromium (Cr6+)
5.    Polybrominated biphenyls (PBB)
6.    Polybrominated diphenyl ether (PBDE)
7.    Di-(2-ethylhexyl) phthalate (DEHP) RoHS 3 directive (2015/863)
8.    Butyl benzyl phthalate (BBP) RoHS 3 directive (2015/863)
9.    Dibutyl phthalate (DBP) RoHS 3 directive (2015/863)
10.  Diisobutyl phthalate (DIBP) RoHS 3 directive (2015/863)


All well and good. But in everyday speak, we always talk of RoHS compliance, and rarely consider which Directive to which it complies. At my previous company, if we were asked if a product, stocked upon our shelves was RoHS compliant, the answer was “Yes, at the time of manufacture” When requesting RoHS compliance, because the directive is rarely, if ever, stated, we must always consider, and be aware of, the date of manufacture of the product before we implement its use. This is not usually a problem at Aerco Ltd, as we are proud to offer Full Traceability on the majority of the items that we hold in stock, and can inform you if the product we offer does not. So ask when you request a quote. 


Also, new substance restrictions being considered for introduction in the next few years include phthalates, Brominated Flame Retardants (BFRs), Chlorinated Flame Retardants (CFRs), and PVC. Yes, PVC. This means that all PVC insulated wires will no longer be RoHS compliant. However, Alpha Wire’s EcoGen™ Wire and Cable products are free of all of these, so, if you are involved in designing new products, call us at Aerco Ltd and we shall insure that your products are future proof. 

To learn more cable and wire services and products at Aerco, please message us  or call us on 01403 260206.

Defense de Fumer

ecogen from AlphaWire logo in various green letteringOn the 4th May 1982, HMS Sheffield, a Type 42 Guided Missile Destroyer being deployed in The Falklands Conflict, was attacked by two Argentinian Super Etendard aircraft armed with Exocet Anti-Ship Missiles. The missiles scored a direct hit, but whether or not they exploded is open to conjecture and debate. However, what is beyond debate is that damage caused by the missile impact severed the high-pressure fire main on board, and the resultant fire, caused by burning rocket propellant, ignited diesel oil from the ready-use tanks in the engine room, and other inflammable materials used in the ship's construction. Twenty crew lost their lives, and the fires continued to burn unchecked for a number of days after the ship was abandoned. The ship finally floundered on the 10th May.

On the 18th November 1987, a lit match dropped on an escalator at Kings Cross Tube Station resulted in a fire. Thirty-one people, including London Fire Brigade officers, died and 100 people were taken to hospital, 19 with serious injuries.

Although there were other major contributing factors in both cases, the use of PVC insulated cable is both situations did not help, and probably made bad things worse.

When PVC burns, contained within the smoke is Hydrogen Chloride gas. When this condenses with water vapour, or onto a wet surface, Hydrochloric Acid is formed. On the Sheffield, this acid burnt through the printed circuits on the Fire Fighting equipment, allowing the fire to get out of control, and at Kings Cross, people in poorly ventilated areas, trying to escape, choking and suffocating in the dense acrid smoke, were unable to safely evacuate.

We learn by our mistakes, and new materials were sought that could replace PVC, but without the harmful effects of acidic smoke. Hence the introduction of Zero Halogen cable, which is produced without using any of the Halogen group of elements, Florine, Bromine, Iodine and Astatine, as well as the Chlorine found in PVC. Materials within the Polyethylene family have always been favourite, as well as Silicone, but recently a new weapon has been added to the arsenal.

Alpha Wire Inc, for whom Aerco Ltd are Premier Distributors in the UK, have recently introduced the EcoGen range of cables. EcoGen products contain no halogens, phthalates, or heavy metals. The mPPE thermoplastic insulation and jacketing can also be easily recycled. They meet RoHS and WEEE requirements for the elimination of hazardous substances and recyclability.

If you have a need or desire to move away from using PVC insulation, contact us at Aerco Ltd, and we shall be happy to guide you to the right product for your requirements.

To learn more cable and wire services and products at Aerco, please message us  or call us on 01403 260206.

Breaking Old Habits

Close up of cable split into 4 various coloured wiresWe all do it. We stick with the familiar, the ol’ faithful, the trusted recipe and the lucky pants. It’s worked before, so we know that it will work again. But if that’s the case, why isn’t everything made of wood, bone, leather and stone?

Because every now and again, something new comes along, a new material, a better way, one that will, in time, become the new standard, and that is what is happening today.

Alpha 3070 is a 24awg, 600V  and 105°C rated, UL1015 PVC insulated hook-up wire, and as standard as you can get. A 1000ft reel weighs 2.46kg, and it has an overall diameter of 2.23mm. This is what a colleague of mine called electric string, it was the base level in any design requiring 600V and 105°C

But, Alpha 6712 is also a 24awg, 600V and 105° rated cable, part of the EcoGen™ range. Approved to UL AWM 11028 it contains no halogens, phthalates, or heavy metals. The mPPE thermoplastic insulation is also easily recycled. It meets RoHS and WEEE requirements for the elimination of hazardous substances and recyclability. But, that’s not all. The overall diameter of this product 1.09mm a reduction of over 50%, and a 1000ft reel weighs 1.03kg, a reduction of 58%!

If it wasn’t for the other approvals that apply, this would bring it close to the requirements of cables used in avionics, and the savings in so called lifetime cost are not to be ignored either. With lighter, reduced diameter looms, the payload or the cost of transportation can be greatly reduced, decreasing the Carbon Footprint of your products.

So, if you are working in a design capacity, and you are about to go with the ol’ faithful, stop a moment, and contact us at Aerco Ltd, and we shall be pleased to help you break a habit of a lifetime

To learn more about the cable and wire services and products at Aerco, please message us  or call us on 01403 260206.

Aerco stocks zero-halogen EcoGen cable from Alpha Wire

Three EcoGen cables showing internal multi coloured wiringAs a premier UK distributor of Alpha Wire, Aerco stocks the EcoGen™ range of high-performance wire and cable products that contain no halogens, phthalates or heavy metals. With mPPE thermoplastic insulation and jacketing that can be easily recycled the product range fully meets RoHS and WEEE requirements for the elimination of hazardous substances and recyclability while offering considerable size and weight savings when compared to traditional PVC and XLPE wire and cable.

The dangers of PVC insulated cable when major fires occur cannot be overstated.  When PVC burns hydrogen chloride gas is formed and when this condenses with water vapour or on to a wet surface, hydrochloric acid is formed sometimes with catastrophic consequences.

This has been proved to be a major factor in conflagrations such as, in 1982, when HMS Sheffield was lost in The Falklands conflict with 22 members of the crew losing their lives and in the 1987 escalator fire at Kings Cross tube station when 31 people died.

The recognition of these dangers led to the introduction of zero halogen cable that is produced without using any of the halogen group of elements, florine, bromine, iodine and astatine, as well as the chlorine found in PVC. Materials within the polyethylene family have always been favourites for this technology as well as silicone, but recently EcoGen products with mPPE insulation and jacketing developed by Alpha Wire have taken the technology to a new level. 

To learn more about the cable and wire services and products at Aerco, please message us  or call us on 01403 260206.

The incredible shrinking world

Porthcurno Bay, CornwallIf you are ever down near Land’s End, you could do worse than visiting The Porthcurno Telegraph Museum, located in the small eponymous coastal village. This was the point at which many submarine telegraph cables came ashore. The museum, which opened in May 1998, is housed in the former telegraph facility. Above the beach was a small building, where the operator would send and receive messages to and from the far reaches of the Empire.

Transatlantic cables of the 19th century consisted of an outer layer of iron and later steel wire, wrapping India rubber, under which was a layer of gutta-percha, which surrounded a multi-stranded copper wire at the core. The portions closest to each shore landing had additional protective armor wires. Gutta-percha, a natural polymer similar to rubber, had nearly ideal properties for insulating submarine cables, with the exception of a rather high dielectric constant which made cable capacitance high. Gutta-percha was not replaced as a cable insulation until polyethylene was introduced in the 1930s.

Each cable carried but a single message at a time. For the Empire. The British Empire. The biggest Empire the world has ever known until now. One line of communication for India, one for Canada and one for Australia. One. If you only have one line, what data is sent, and what isn’t?

Even so, it was the envy of the world. This was the biggest and the most important communication hub in the world. Until then, the only way to send messages was by Packet Ships, and they could take months.

This is an incredible concept in this day and age of mass, constant communication, most of which is ephemeral and inconsequential, after all, who really needs to know what you are having for lunch? One thing is certain though. Technical development and Innovation is snowballing, driven by ever increasing speeds and levels of communication. But we have to keep up. There is no point of talking if nobody is listening. We at Aerco Ltd listen. Call us with your requirements. We will tell you if there is a standard product that meets them, and if not, we will guide you through the design process to produce one that does, advising you of the pitfalls, and coming up with an affordable solution within a realistic time scale.

Modern undersea cables are constructed of armoured fibre optics, sending data at the speed of light, and we rush head long into the future, surfing on the wave of ever increasing speeds and levels of communications.

Aerco Ltd are currently looking into entering the Fibre Optic world, and hope to be making announcements in the near future, so, if you have any requirements regarding Fibre, give us a call. We shall endeavour to treat them with the level of professionalism you have come to expect of us.

And the museum? Start with a visit to their website at www.telegraphmuseum.org and as for the world, it may be getting smaller, but I wouldn’t want the job of painting it!

To learn more cable and wire services and products at Aerco, please message us  or call us on 01403 260206.

Whats in a name? Clarity for wire and cable definitions

Multiple black cables on a blue background"What's in a name? That which we call a rose, by any other name would smell as sweet." Said Juliet in Act 2 scene 2 of the bard’s classic play. My son always says that Romeo was a dilettante, who would have abandoned Juliet once he had had his fun, if the antagonism between the families hadn’t forced him into making commitments he would not have otherwise made. So, as in cable, names are important, very important indeed.

As an example, it is not unusual to receive a phone call on the lines of “Do you do Cable?” to which we answer yes, “because I want it installed by Saturday for the football!” is the response!

So, definitions are important. But the definitions in the cable industry have been carried over from terms originally used in the industries whose technologies were borrowed, such as the production of rope, ribbon and textiles, and they didn’t always mean the same thing. A wire can be a cable, and a cable can be made of wires. If a conductor is carrying a signal, we tend to call it a wire, whether solid or stranded. The strands themselves will also be referred to as wires. If it is carrying power, we tend to call it a cable. Confused? You will be.

So, a wire is a single insulated conductor, usually employed on its own, or built into a loom or cable assembly. We try not to employ the term for anything else, to reduce confusion.

A cable is a jacketed construction, containing cores or conductors, whether singles, pairs, triples or rarely, quads. These conductors are insulated, in a range of materials depending upon the function, and are constructed of strands, usually solid, 7 strand or 19, although larger numbers of strands are available when greater flexibility is required.

Once a wire gets above a certain size, I would say about 1.0mm², then it becomes a power cable.

As always, it all boils down to communication. Be precise in your description, make sure that both you and the person you are talking to, both understand what you are talking about and are using the same language, and then give us a call at Aerco Ltd, and we’ll make sure that you get the right product for your application, just make sure that it’s not about the football on Saturday.

(by David Cairns)

To learn more cable and wire services and products at Aerco, please message us  or call us on 01403 260206.

That depends....

Computer image of blue electric cable showing internal wiresHow many times have you asked an engineer a question, and had that for an answer? Well, there’s usually a bit more to this statement, and it’s usually “on where you’re starting from”. And this is the case when we try to decide upon a conductor size for a given current.

We are looking for the Goldilocks condition, not too big, not too small, but just right. If the conductor we choose is too big, we will increase the cost of the materials, the weight and the size of the finished unit. If the conductor we choose is too small, we will reduce the life of the unit, and will incur a serious risk of fire. (I know, I did it myself as a very young, very green, design engineer, but only once!) So, we need to look at the factors that choose the conductor size for us.

When we draw power through a conductor, its inherent resistance will cause a rise in temperature, irrespective of the material. This is why, unless other factors decide otherwise, annealed copper is the first choice as a conductor. It has a low conductivity, 94% at 0°C, at £3.60/kg, in comparison to 100% for silver, at £382.30/kg. (The latter figure is why we use copper!) However, that loss of energy will be converted into heat, and as we’ve discussed before, heat is the enemy of cable. The major factor will be the insulation material, PVC for instance, will rapidly fail at temperatures above 105°C, so any current that causes a PVC insulated cable to go above this temperature is too high. Bear in mind, also, that 105°C is pretty hot, especially if you touch it, so you will need to consider what temperature rise the system can tolerate.

But, “that depends on where you’re starting from.” If the ambient temperature of the environment in which the cable is being used is, say 20°C, then you can deploy a higher temperature through the conductor, than if the ambient temperature is say 50°C.

Added to this, we have bundling. Penguins on an ice floe huddle together to keep warm, and take turns at being on the inside, where it is more difficult for the heat to escape. So it is with cable. On the inside of a bundle, the heat generated is shared rather than escapes, in effect, raising the ambient temperature. So, we have to apply a de-rating factor to the applicable current, dependent upon the size of the bundle.

So, the size of a conductor required for a given current depends upon the ambient temperature of the environment in which the device will be used, the temperature increase that can be tolerated in normal usage, the ability for the generated heat to escape, and the insulation material that has been chosen.

If you’re not sure after all of that, (I refer you to my fire), call us at Aerco Ltd, and we shall be only glad to help you choose the right products for your application. And sell you them.

(by David Cairns)

To learn more cable and wire services and products at Aerco, please message us  or call us on 01403 260206.

 

Curly Cords Untangled

Red, green and blue phone handsets dangling on their curled cords We are all familiar with curly cords, but most of us never give them a second thought. Yet these babies have a backstory of their own that borders on alchemy. All solids have a “memory” of what shape they are supposed to be, and if deformed, their molecular structure will endeavour to return to the original shape. This memory can be changed or adapted by applying certain principles, and I will attempt to explain them here.

The molecules in an extruded thermoplastic insulated jacket will be connected to each other by so called bonds. When a force is applied, stretching these bonds, like elastic bands, they will pull themselves back together. In making a curly cord, we rearrange these bonds to suit our design. To do this, the cable is first warmed to make it more pliable, and then wrapped around a mandrel. The number of turns, and the diameter of the mandrel chosen will be defined by the requirements of the finished product. The tails, as specified, will be cut to the required length. The whole assembly will then be placed into a warming oven for a few hours, and cooked. This causes the bonds in the material to break down. Once removed, the assembly is allowed to cool gently, during which process new bonds will be formed at a molecular level, creating a new memory. This is one time when the thickness of a cable jacket is defined by a factor other than voltage. The more material we have, the stronger the memory will be.

There are limits. If we overstretch the cable, we will exceed the elastic limit, and cause the internal bonds to break, and the cable will not return to its original shape. Hence a stretch of 4:1 is usually stated as the norm. Some materials are better than others, polyurethane is usually the best.  The size of the mandrels and of the ovens employed are another limiting factor, 2.5m for the coil in its relaxed state is usually the norm, but this can be exceeded in exceptional circumstances by feed the assembly slowly through the oven, by hand, in one side and out through the other.

The important thing to remember here is that each cord has to be manufactured individually, with the relaxed length, the coil diameter, the number of turns, and the length of the tails being specified at the time of order. You cannot supply curly cable by the yard.

(by David Cairns)

To learn more cable and wire services and products at Aerco, please Contact us .

 

Alpha Wire Expands Coaxial Cable offering sizes down to 50 AWG

New Micro Coax cable offered in smaller sizes to meet the growing need for signal transmission in confined spaces

Alpha Wire has expanded its Coaxial Cable product line to include Micro Coax sizes from 32 AWG to 50 AWG.  With the addition of Micro Coax, Alpha Wire now offers Coaxial cable products ranging from 10 AWG to 50 AWG.

The new Micro Coax cable line will be offered as standard constructions and are ideal for customers looking for signal transmission options, especially when designs offer limited space for cable routing.  “Alpha’s new 50 Ω Micro Coax line will provide customers with the ability to ensure signal integrity within the increasingly small confines that many designers are working with,” says Hillary Riden, Product Specialist at Alpha Wire. “With an operating temperature range of -70°C up to 200°C, the new micro coax line is ideal for everything from medical endoscopes to industrial inspection applications.” 

To learn more about the new Micro Coax product line, please Contact us .

Appealing Annealing

Close up of reels of annealed copper wireTinned annealed copper wire. We’ve all seen and used the term, but what does it mean? Annealing is a process in metallurgy when a metal is heated to a specific temperature, and allowed to cool gently. This creates a lattice within the wire comprised of small crystals, resulting in improved ductility and reduced hardness, making it more workable, and thus more flexible. By having small, regular sized crystals in a lattice, the molecules can move around each other when the cable is flexed, and more importantly, return to their original position when relaxed.

However, this ideal can be compromised if we subject the cable to excessive bending. If we go beyond the elastic limit of the material by exceeding the minimum bend radius, we create localized heating, which will change the structure of the material, causing large crystals to form. These then become like grit in your suntan lotion, or rocks in a bag of sand, and will cause fracturing in the lattice when it is flexed. The fracturing causes the resistance of the wire to increase, and the resultant heat will create more large crystals.  The phenomena will snowball, until the conductor fails, and the cable will no longer work.

Hence, we incorporate strain relief devices into our designs, and publish minimum bend radii for cables. We can also design cables to be more flexible, and to be able to cope with torsional flexing, if necessary. There are quite a few techniques we can employ, including the shape of the finished cable, (this is why telephone cords are flat and not round) and the inclusion of fillers to absorb the energy. It helps if we know at the design stage what the requirements of the finished cable are.

So, the next time your teenager, who always wraps their headphones tightly around their phone, tells you that they no longer work, and that they need some new ones, you can tell them why. Not that they’ll listen.

 

Contact us for queries on cable/wire

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