Call us on: +44 (0) 20 8405 6789
(0) Your Quote
  • 24hr. Next Day UK delivery
  • Nationwide distributor of power cable accessories
  • Supplying the trade for over 30 years

Question and Answer

  • Guest Blog: Cable Cleats V Stainless Steel Cable Ties

    Should you be using cable cleats instead of stainless steel cable ties for your next project? ETS stocks both product types and we’re often asked which is the most suitable for a particular installation.

    ETS recently caught up with Richard Shaw from cleat manufacturer Ellis for his thoughts on stainless steel cable ties and cable cleats. Here is what he said.

    "Claims have recently begun to emerge from certain quarters that imply stainless steel cable ties can be placed on an equal footing with cable cleats.

    Amongst the claims being made are:

    • 'Metal ties actually provide as much protection in the event of a short circuit as cleats.'
    • 'Stainless steel cable ties are less expensive on average than cable cleats.'
    • 'Stainless steel cable ties provide an equal or better level of risk mitigation at lower cost and quicker time to install.'

    My problem with these assertions is that although stainless steel cable ties and cable cleats are complementary products, the area of overlap is extremely small – and when explored fully, it’s immediately apparent that it’s an area of considerable risk. What this means is that the kind of claims being made about stainless steel cable ties are, at best, extremely misleading.

    Product v Product

    Cable cleats are made in a variety of materials to accommodate a wide range of installation conditions and locations. Our product range alone features stainless steel, mild steel, extruded aluminium, cast aluminium and a wide range of polymers. Many of our cleats combine metals and polymers to deliver the best solution.

    Cable cleats also come in a number of different varieties. Again using our product range as an example, we supply cable saddles, cable straps, flexible cable cleats, hinged cable cleats and even the most straightforward of cable clamps.

    In contrast, a stainless steel cable tie is just that – a cable tie available solely in stainless steel.

    Creating an analogy about the two products highlights the scale of the differences between them perfectly: A stainless steel cable tie manufacturer may claim their wrench is as good, if not better, than the cable cleat manufacturer’s. But the cable cleat manufacturer retorts by pointing out they don’t just have one wrench, they have an entire tool kit.

    Price

    Before even considering the question of price, we first have to decide which of the many types of cable cleat we should compare the stainless steel cable tie with.

    In the examples I’ve seen, the price comparisons between the two tend to pit cable cleats at the upper end of their range against cable ties. While this may seem unfair, the comparison has been made so let’s see how it stands up to scrutiny.

    First, it’s obvious that a single stainless steel cable tie will be cheaper than what is the strongest of stainless steel cable cleats – after all, you get what you pay for.

    But even so, would the entire cost of both product and installation be cheaper if you used cable ties rather than cleats? It may surprise you to discover that the answer is almost certainly no – but why?

    When considering the strongest stainless steel cable cleat it is ludicrous to try and equate it to a single stainless steel cable tie. Yes, both products are made from similar material, but there is, of course, a lot more steel in a cleat than a tie.

    Therefore, in order to make a direct comparison you need to consider the cross sectional area of the material being used – a calculation based on width, thickness and the number of times it is wrapped round the cables.

    Cable ties are typically less than 20mm wide and less than 0.4mm thick and so have a cross sectional area of less than 8mm2.

    If the strap is wrapped round twice we have material with a maximum cross sectional area of 16mm2 securing the cables. In comparison, a top of the range stainless steel cleat will have a cross sectional area of 100mm2.

    Harking back to simple physics, the ultimate tensile strength of a material is proportional to its cross sectional area – and that’s something you simply can’t argue with.

    Using the information above, and all relevant supporting short circuit test data, if the calculated fault level for a system required the installation of an Ellis Emperor cleat every 300mm, it would come as a great surprise if the cost of the equivalent appropriate number of cable ties was less than the cost of the cleats – and that’s before you even take into account the time it would take to install them all.

    Short-Circuit Testing

    The final point I’d like to address is short-circuit testing, and in particular the question of whether the data gathered from a test is transferable to a real life installation?

    As far as cable cleats are concerned, the answer is usually yes. This is because, under fault conditions, a cable cleat constrains all the forces generated between the cables. The mounting structure has no influence on the cleats performance and so it should perform at the level indicated on the short-circuit test certificate.

    The situation is nowhere near as cut and dried when it comes to stainless steel cable ties – mainly because of the difference in fixing methods. Typically there are three ways in which a cable tie is used to attach cable to ladder:

    1. The cable tie can be wrapped around both the cable and the rung.
    2. The cable tie can be installed using a mounting bracket, which fixes to the rung.
    3. The cable tie can be fed through perforations on the ladder rung if they are present.

    Of these three methods, both option 1 and option 3 introduce significant variables that will have an impact on likely performance during a fault. In both cases a foreign body is being introduced to the loop that contains the cable.

    As such everything from ladder material to rung profile; types of hole and sharpness of edges; and even surface finish and cable diameter can have an impact on the whole arrangement.

    As such, it’s impossible to say that the result of a short-circuit test on a stainless steel cable tie is transferrable to the real world, unless the installation is identical to the testing set-up.

    Of course, installation option 2 is more likely to deliver real-life performance that matches short-circuit testing performance for a cable tie. But in this scenario both the cost of the parts required, and the installation time will increase significantly, making it even less competitive when the number of ties to cleats ratio is taken into account.

    The Final Decision

    What needs to remembered when considering the respective merits of both stainless steel cable cleats and cable ties is that the primary concern for all those involved in electrical cable installations should be safety.

    In order for an electrical installation to be deemed safe, cables need to be restrained in a manner that can withstand the forces they generate, including those generated during a short-circuit.

    Yes, both cable ties and cable cleats have their place in the specification picture. And yes, there is a minimal amount of overlap where it is feasible that an installer or specifier could choose one over the other. But it is minimal, and the specification decision shouldn’t be made based on misleading claims aimed squarely at undermining the sales of a tried, tested and trusted solution.

    All cable cleats designed and manufactured by Ellis Patents undergo a thorough testing program prior to launch, including short-circuit testing. Even after launch, products are regularly short-circuit tested and will perform at the level on the relevant certification during a real life short-circuit scenario.

    Not one of our installed cable cleats has ever failed. Therefore, make sure you make the correct specification decision on your next electrical installation.

    If you don’t the dangers posed by a short-circuit are plentiful – costly damage to cables and cable management systems, plus the risk to life posed by incorrectly installed live cables.

    Official Suppliers

    ETS Cable Components are an official supplier, stockist and distributor of Ellis Patents cable cleats.
    ETS also supplies a range of stainless steel cable ties as well as tooling.

    If you would like any help with choosing the right product for your next project, please get in touch with the knowledgeable ETS sales team: +44 (0) 20 8405 6789 | sales@etscablecomponents.com

    Cable Cleats Brochure

    Cable Cleats

    A brochure is available setting out ETS' wide range of cable cleats. To find out more click here.

    Please share if you found this article useful.

  • What Is Exothermic Welding And Why Is It Used?

    Exothermic welding – also known as thermite welding or exothermic bonding – is a process for permanently joining earthing (grounding) or lightning protection conductors together.

    An exothermic weld can be especially useful for joining dissimilar metals. The process has the advantage in that it requires no external heat source and works by employing a chemical exothermic reaction of a thermite composition (weld powder) to heat the conductors to a point where a low resistance, mechanically sound molecular bond is formed once cooled.

     

     

    Exothermically Bonded Connections

    Although mechanical connections and exothermically welded connections are very similar in their applications, their performance can differ greatly.

    Our “Traditional” and “PLUS” exothermic welding material is suitable for welding these materials together:

    • Copper
    • Mild steel
    • Bronze
    • Brass

    Specialised applications would also include cast iron and stainless steel materials, please speak to our Sales Team: 020 8405 6789 or email: sales@etscablecomponents.com.

    Exothermic welding is the only reliable means of bonding galvanised mild steel to copper conductors, e.g. fence earthing or structural steel applications. ETS is the authorised UK re-seller and stockist for ERICO CADWELD® exothermic welding products

    CADWELD®:

    • Will not deteriorate with age.
    • Eliminates any risk of loosening or corrosion due to its molecular bonding characteristics.
    • Will resist repeated faulty currents.
    • Offers the lowest possible earth path resistance.
    • By visual inspection can be quality controlled.

    Exothermic Welding Training

    ETS can provide in-house training at short notice (UK only), either at our training facility or at a customer’s site for the ERICO CADWELD® exothermic welding system.

    These courses are designed to show and teach the correct preparation procedures, use and applications of the CADWELD® welding system. You can find out more about our exothermic welding training courses here.

    Watch this video on exothermic welding:

    Please share if you found this article helpful or interesting.

     

     

  • Q&A: What are the differences between crimp connectors and mechanical shear-bolt type connectors?

    Question:

    What are the advantages or differences between using mechanical connectors over the traditional crimp connector system?

    Answer:

    Crimp connectors have been popular for many years, but mechanical connectors with bolt heads, which shear off once a certain torque, are becoming universally acceptable.

    The advantages a modern mechanical connector has over crimp connectors are:

    1. They are range taking.
    2. They do not require the additional expense of crimping systems.
    3. Eliminates the chance of the jointer using an incorrect die set.
    4. No sharp edges, which may be caused when using hexagonal die-sets.

    However, there are 3 distinct disadvantages to using connectors with shear-bolt technology:

    1. Mechanical terminals can be considered more expensive than traditional crimp systems, especially if the end user is fully tooled up for crimping.
    2. It has a larger profile than its crimp connector equivalent, therefore all systems may not be easily installed. Especially push-on types.
    3. The cross-section may not always be symmetrical, which can make treatment over the connector area more critical.

    These pro's and con's need to be considered when deciding on choosing a mechanical or crimp connector system. Contact our sales team for more information on the best lug types for your application and to find out more about our range of cable connectors and terminals.

    If you found this article helpful or interesting, please share it!

  • Q&A: What are the Advantages and Disadvantages of Using Separable Connectors?

    Question:

    I'm thinking of using separable connectors for a termination, what are the pro's and con's of using these deadbreak connectors over traditional Heatshrink or Coldshrink terminations?

    Answer:

    Separable connectors, also know as screened elbows or tee connectors, offer an alternative method of terminating cable.

    As with any method of cable termination there are positives and negative, as listed below:

    Advantages:

    - The connector is fully screened making it unaffected by adverse environmental conditions.
    - The two Faraday cages featured within the connector eliminate the need for separately installed stress control and taping of components.
    - Tee connectors can 'piggybacked', allowing more than one cable to be attached to a single bushing.
    - Each unit is factory tested for partial discharge and power frequency withstand (dependant on manufacturer).
    - Can be installed both indoor and outdoor environments.
    - Connectors can be utilised to joint cables together, using the appropriate mating part.

    Drawbacks:

    - The equipment and connector must have the correct bushing interface, unlike with heat shrink and cold shrink terminations.
    - Separable connectors are best suited for single core cables (Although three-core cables can be modified to suit).
    - Tends to be more expensive than the equivalent cold and heat shrink terminations.

    For more information on our range of separable connectors, heatshrink and coldshrink terminations, please contact our Sales Team.

    If you found this article helpful or interesting, please share it!

  • Q&A: What are the different earthing uses of the two forms of Bentonite?

    Question:

    What is the difference between the two forms of bentonite, do they both serve the same earthing applications?

    Answer:

    Bentonite moisture retaining clay is available in two forms, Granulated and Powder. Granular is the preferred option for filling trenches where the conductor is covered and then water poured over and mixed in the trench. The powder form of Bentonite, on the other hand, is the preferred method for pouring into bore holes to ensure the mixture is of a thin enough consistency to reach the bottom of the bore hole.

    Over time both types would be washed through and potentially, to maintain the required resistivity reading, more product would need to be added in the future. An alternative to using bentonite as a ground enhancement material, is Marconite which offers a more permanent solution.

    If you found this article helpful or interesting, please share it!

  • Q&A: Maintaining an IP66 seal throughout a cable gland connection and equipment entry

    Question:

    I need to install a brass CW gland into an IP66 enclosure, however I need to ensure the IP rating is maintained throughout the cable connection and equipment entry. How is this done?

    Answer:

    All cable glands are supplied with an IP (ingress protection) rating, which refers to the level of sealing effectiveness as defined in IEC 60529 (Formerly BS EN 60529:1992).

    It is important to note that the IP rating of a cable gland relates to the outer seal of the cable gland, where the cable itself is connected to the gland. 

    maintaining an IP66 seal throughout cable gland equipment entry

    The IP rating supplied with the gland, usually does not related to the protection offered to the equipment or enclosure entry. Even if the enclosure itself is, for example, IP66 rated, most glands will only provide protection to IP54.

    Where this is the case, a nylon washer (also known as an entry thread washer) should be installed between the cable gland and the equipment entry, as per the diagram above. The addition of a nylon washer, or red fibre washer for Hazardous Areas, increases the ingress protection to IP66.

    Although there are gland types that come supplied with entry thread washers, it is important to check individual cable gland design for more information regarding outer seal and equipment entry Ingress Protection ratings.

    If you're unsure, please contact a member of our Sales Team and we'll be happy to advise you on the correct cable gland and IP rating for your requirements.

    If you found this article helpful or interesting, please share it!

  • Q&A: When Should A Hazardous Area Cable Joint Be Used?

    Question:

    In what situation and applications should I use a Hazardous Area cable joint over a standard resin-filled joint?

    Answer:

    A Hazardous Area joint kit should be used if you have a requirement for your cable jointing solution, to be flame retardant, halogen-free or hydrocarbon resistant.

    All of our 3M Hazardous Area joints have been tested extensively to prove their performance within hazardous and harsh environments and the effects of hydrocarbons and chemical solvents on resins and joint bodies.

    The LVI-3 range of cable joints have been successfully installed within ATEX rated Hazardous Area including mines and quarries, underground applications, petrochemical sites and offshore areas where there is a risk of flame or explosion.

    The specialist joint shell, which is flame retardant, hydrocarbon resistant and halogen free, is filled with a specially designed polyurethane resin, which is a highly modified joint resin mix, which makes the resin flame retardant, halogen free and virtually unaffected by immersion in either hydrocarbon or chemical solvent solutions.

    If you found this article helpful or interesting, please share it!

  • Q&A: Are bushing extenders available for Euromold Interface C bushings?

    Question:

    Are bushing extenders available for the Nexans Euromold Interface 'C' bushings? I have noted extenders are available for Interface D and E bushings but cannot find any examples for the interface C range.

    Answer:

    Unfortunately 400series bushing extenders do not exist. Being a European-designed product, it as always felt that sufficient control could be exerted over equipment manufacturers to negate the need for such a product. Unfortunately that hasn't always worked and Nexans Euromold were forced some years ago to come up with a solution which is:

    - Use a 400series tee connector, i.e. (K)400TB, for which Euromold produce an insulated rod/contact assembly to take the place of the cable which would normally be present.
    - The bushing is then “extended” by using a conventional (K)400CP connecting plus and thread assembly.

    Euromold 400 series bushing extension solution

    Although it doesn't look conventional, it is however the only solution and usually available within a few weeks, from ETS Cable Components.

    Please note that this solution is only valid up to 24kV maximum.

    If you found this article helpful or interesting, please share it!

  • Q&A: How to Properly Remove A Bonded Screen With A Removal Tool?

    Question:

    I'm about to use a bonded screen removal tool for the first time, how do I make sure it works correctly and the screen is properly removed from the cable?

    Answer:
    When terminating or jointing MV cables with a bonded semi-conductive screen, this will have to be shaved from the cable primary insulation to the dimensions given within the accessory installation instructions. There are a variety of tools available that will perform this task, however when using a purpose-made screen removal tool the following points should be noted to ensure the cable is prepared correctly:

    Ensure the blade is set to the correct depth. Excessive removal of the cable insulation could increase the electrical stress at the point of removal, particularly with air-clearance terminations (Heatshrink and ColdShrink types). The best way to ensure the correct depth is to practice on a piece of unused cable first.

    Some tools require the application of silicone grease to the semi-conductive screen in order to lubricate and ease tool rotation. Fully familiarise yourself with the usage instructions supplied with the tool you are using and practice on a few lengths of unused cable to “get the feel” of the tool.

    Ensure the core is perfectly straight. Any bend in the cable can lead to the screen not being removed evenly around the circumference. This could happen to the underside of the cable and may not be immediately noticed, potentially causing partial-discharge issues.

    Using a specialist tool usually results in a perfectly prepared core, but if small amounts of bonded semi-conductive screen are left on the cable these can be removed with the use of a fine abrasive, non-linting cloth (120grit minimum). Care should be taken to only abraid cables circumferentially (NOT longitudinally) to avoid creating a partial-discharge path along the cable insulation.

    Once you have prepared your core(s), the primary insulation will require cleaning to ensure any loose particles are removed. Always clean polymeric insulation from the exposed conductor end, along and TOWARDS the semi-conductive layer in one direction, avoiding inadvertently contaminating the insulation with any semi-conductive compound residue.

    There are a number of different types of bonded screen used on cables. Although the aforementioned procedures are common to most polymeric semi-conductive compounds, it is important to confirm that your tool and cable/s are compatible before commencing work.

    ETS Cable Components offer a variety of quality-manufactured cable preparation tools from GBZ-Mannheim and Nexans. Please contact our Sales Team for further information, prices and advice.

    If you found this article helpful or interesting, please share it!

  • Q&A: How Do I Use A Trefoil Cleat on Triplex Cables?

    Question:

    I need to secure a cable in triplex formation with the use of a trefoil cleat, how would I go about doing this?

    Answer:

    Triplex cables are formed by having their three cores twisted around each other, this causes an issue when trying to secure the cable with traditional trefoil cleats. As the relative position of the cable varies along the cable run, the three cores will be in a different 'twisted' position at each cleat interval.

    triplex cable

    The overcome this problem, a SFT triplex cable former is available. The inner liner is applied around the cable, giving it a uniform profile allowing it to be fixed within a two-bolt LSF, VRT Vulcan or single way ES Emperor cable cleat.

    The triplex liner is manufactured from LSF Zero Halogen (LSZH) materials and thus is suitable for applications where LSZH properties are required.

    nylon-two-bolt-cleat-triplex vulcan-cleat-triplex emperor-cleat-triplex
    2LSF Cleat with Triplex Liner Vulcan Cleat with Triplex Liner Emperor Cleat with Triplex Liner


    If you found this article helpful or interesting, please share it!

10 Item(s)