A guide to metal cable management

The cable management system you choose impacts speed and ease of installation. It can also help or hinder your installation design and layout. The reasons include, just to name a few:

• Fixings
• Loadings
• Bend radius

Correct specifications are vital, as this will affect future-proofing and scalability. It determines whether or not your cable management is fit for purpose. For example:

• Is it robust enough to stand up to normal levels of vibration from its environment?
• Can it deliver the application’s intended service life?

What you need to consider:

Material type determines how long a correctly installed cable management system will last. Under-specification can result in corrosion and shorten your application’s service life. On the other hand, over-specification can increase material costs and installation times without giving you any more value in terms of durability or service longevity.

Specifying the correct cable management for different environments is no easy task, no matter how experienced you are. First you have to determine the best solution – cable ladder, cable management tray, cable management basket or cable trunking, for instance.

It’s not just the material and finish that have to be considered, but width and depth and the correct weight – heavy, medium or standard duty?

With so many variables, it’s erroneous to view cable management with a one-size-fits-all approach.

The importance of the environment:

Before you can decide that, you need to understand the environmental factors that will impact your application.

• Will it be outdoors, exposed to the elements?
• And what of the atmosphere?
• Will it be inland or in a coastal location?
• If it’s indoors, will the air be polluted?

Standard cable management systems are usually pre-galvanised or hot-dip galvanised steel. There are corrosion risk categories for zinc, of which there are six categories in all. These start with C1 (very low), which would typically be inside an insulated building with relative humidity.

The scale rises to C5I, which is very high industrial. In this situation, we’re talking about several possibilities:

• External environment with a significant amount of humidity and an aggressive atmosphere
• Interior location with almost constant water condensation and high levels of pollution
• Coastal areas with high salinity

You can familiarise yourself with the scale here.

Understanding indoor environments is straightforward. Outdoor environments require more investigation. If you don’t know about the British Galvanisers’ Corrosion Map of the UK, check it out. It tells you which locations are most at risk of accelerated corrosion.

While galvanisation protects the base metal from rust, there are other corrosion risks with galvanised cable management.

White rust

When a fresh zinc surface is stored in a wet environment without enough oxygen and carbon dioxide, a white, powdery and porous substance called white rust appears. If your cable management solutions’ zinc coating is light, as it is with electro-zinc or pre-galvanised products, white rush can cause damage. Systems with heavier coatings should not suffer weakened integrity due to white rust.

Galvanic corrosion

Also called bimetallic corrosion, this electrochemical process happens when two dissimilar metals are immersed in a conductive solution and are electrically connected. One metal (the cathode) is protected, whilst the other (the anode) is corroded.

Zinc Whiskers

This type of corrosion is a particular risk to business-critical equipment in data centres. Metallic filaments that can grow on any galvanised surface and detach into the atmosphere, zinc whiskers need to be considered in the specification for any environment involving sensitive equipment. You should specify a powder-coated or stainless steel over galvanised cable management solutions.

The need for insulating materials

Cable management systems made of insulating materials are unaffected by corrosion and ensure good protection against outdoor exposure, UV rays and chemical agents. This resistance is ensured by the raw material in itself, not by applying a coating to the final solution.

Galvanised solutions

Galvanising steel is a cost-effective way of protecting the material, which works in different ways:

• The zinc coating weathers at a very slow rate for a long life
• The zinc coating corrodes preferentially, providing sacrificial protection to any small areas of exposed steel
• The surrounding zinc prevents ‘creepage’ on larger exposed areas

Pre-galvanised vs hot-dipped galvanised solution

Pre-galvanised means that sheet steel has been through a hot-dipped galvanising process at the point of manufacture. Hot-dipped galvanised products are completely immersed in a bath of molten zinc at 450°, until the temperature of the item is the same as that of the zinc.
During this process the molten zinc reacts with the surface of the steel to form a series of zinc/iron alloys. When the item is removed from the zinc bath, it has a zinc coating and solidifies. The excess zinc is removed for a smooth finish. This extra covering of zinc during the hot-dip process makes hot-dipped cable management solutions much more robust and resistant to corrosion.

Best for dry interiors

Pre-galvanised cable management is suited for dry, interior environments. When cable management is on display, its clean, smooth finish is also ideal for exposed cable management installations.

Electro-zinc finishes give you low-cost protection in non-corrosive environments. If appearance counts, you’ll like the look of electro-zinc. It also gives you the opportunity to achieve colours in post-treatment.

One good example of an indoor solution to use is cable conduit – specifically, PVC coated metal. This type of conduit protection works extremely well in industrial environments, such as factory wiring and connections to machines, or as one of your HVAC components, providing high abrasion resistance.

Best for outdoors

Hot-dipped galvanised cable management does tend to cost more, but you’re getting more effective protection, as long as any exposed steel after cutting is coated with galvanised paint.

Note, it’s good for external installations as long as there is no additional risk of corrosion, such as exposure to chemical or marine elements.

If you need a long service life, consider Corten A steel, which may provide a good solution:

• Material is galvanised after manufacture, with a thicker steel and higher silicon content
• This attracts more zinc in the galvanising bath

For harsh environments, go with stainless steel.

Two choices are:

	Type	Why	Application
Good	Stainless steel 304L	Good weld ability	Brewery, dairy, food and pharmaceutical production
Better	Stainless steel 316 L	Corrosion resistance	Mass transit, ship building, oil rigs, hazardous areas, mining, petrochemicals and rail

 

A great example of stainless steel 316: stainless steel cable ties, with ladder structure for strength and durability. These are also ideal for underground applications.

Where is your best value?

Hot-dipped galvanised cable management costs more – about 35 to 40% more on average. Stainless steel will cost around 40% more than hot-dipped galvanised. While pre-galvanised and electro-zinc look like an attractive option based on price, don’t look at material costs by themselves.

Factor in all variables, including life and installation costs, and consider replacement intervals and operational efficiencies. Without these considerations, you won’t have a well-thought-out strategy for selecting materials.

Download free CADs and try before you buy

Free CADs are available for most solutions, which you can download for free. You can also request free samples to ensure the solutions you’ve chosen are exactly what you need. If you’re not quite sure which product will work best for your application, our experts are always happy to advise you.

You’ll like our flexibility too, if it’s just a small order you need, no problem. Whatever your requirements, you can depend on fast despatch.

Request your free samples or download free CADs now.

Questions?

Email us at sales@essentracomponents.co.uk or speak to one of our experts for further information on the ideal solution for your application 0345 528 0474.