Electrical Cable & Wire Selection Guide for Industrial Use
by Simcona on Jun 27, 2023 4:31:52 PM
Sure, an intricate layout and fancy technology can make an electrical product design sing. But choosing the right industrial cables and wires is just as crucial to optimizing performance, safety, and durability in your build.
With an absurd amount of variety available, it can be overwhelming to browse a manufacturer’s e-store. This cable selection guide hits the high notes of industrial-level sourcing so you can make a wise decision for your application.
8 Cable Selection Guidelines
Following these eight electrical wire/cable guidelines will help you meet your unique requirements, down to the smallest detail:
- Mechanical durability
- Electrical performance
- Heat, flame, & cold resistance
- Corrosion resistance
1. Mechanical Durability
Several elements of a wire assembly influence its strength, starting with its size and protective layers.
The gauge of an industrial cable refers to its thickness. Today’s customers are demanding smaller and smaller designs, which makes the physical side of cable performance a little harder to manage. A thinner cable is easier to sever or smash but there are ways to add protection:
Armoring to Try
Conductor to Try
Polyethylene, Neoprene, nylon, thermoplastic rubber
Avoid jacketing and insulation with weak mechanical properties if your cables are at risk of being stepped on, run over, or cut. Materials to stay away from include:
- Thermoplastic rubber (for cut-through resistance)
- Paper (for filler)
2. Electrical Performance
In a “normal” situation (no chemical fire, unexpected submerging, etc.), there are two main factors in a cable’s electrical performance: length and shielding.
Size requirements are different from at home, where “How long?” might be your only question. For the factory floor, there are entire electric cable guides dedicated to sizing best practices.
Gauge matters too, as thicker cables generally have lower resistance and can handle higher electrical loads across longer distances. Consider the current requirements of your application and select a gauge that can safely carry it without overheating or losing voltage.
Length is still important too, but for more than just physical spacing of its connection points. A cable’s signal decreases as it travels, making excessively long cables a poor fit for applications that need low losses.
Oversized cable is also a waste of money, so only buy what you need. That said, if your assembly might change in location or expand in function later, include some slack and perhaps a service loop.
Shielding, meanwhile, is a feature dedicated specifically to preserving a cable’s ability to carry current.
Electromagnetic interference (EMI) is the enemy of electrical cabling, as it causes cross-talk (noise) and signal degradation. Shielding is a conductive layer that minimizes EMI by acting as a barrier. It may prove a more cost-effective design, as it helps you run farther with less cable before the signal degrades.
Take note of your project’s end-use location and whether nearby objects will play nicely with each other. If you’ve got 20 induction heating machines or automated conveyors in one room, dialing in a specific frequency will be challenging due to cable cross-talk. If you’re spec’ing cables for traffic signals, there’s no need for shielding because only air will surround them.
Your needs in this department are highly dependent on the cable’s intended use.
Benefits of a flexible industrial cable include:
- Fits in tighter spaces
- Less likely to snap
- Easier to use
Consider the flexibility requirements of your equipment, because not all connections need to or should be flexible.
A flexible cable would make sense for a robotic arm that rotates all day. A semi-rigid cable is easy to configure to your desired shape while maintaining its set, making it useful in metal-bending operations. A rigid cable is usually the top performer in high-power applications, like computer setups. They also cost less (usually), so it may be worth going that route if cable flexibility is irrelevant to your project.
A cable’s shielding (if any) is the biggest factor in its flexibility, with spiral shields the most flexible. Jacketing and insulation materials matter too, with thermoset and rubber types offering the most flexibility. Last and probably least important is the conductor type, of which stranded conductors are the most flexible.
Certain cables contain filler materials to improve flexibility:
- Aramid fiber
- Paper (note this is flexible, but has a short flex life)
4. Heat, Flame, & Cold Resistance
Some types of electrical wires and cables can endure high heat, some thrive in freezing temperatures, and a few excel at both. Meanwhile, some cables are popular because they don’t emit toxins while burning, while others are popular because they’re not flammable to begin with.
Choose cables with temperature ratings and fire reactivity appropriate for your application.
- High temperatures – A poorly rated cable will turn to mush, causing mechanical issues, conductor overheating, and insulation breakdown.
- Flames – UL rates cables for circuit integrity during a fire, as well as any smoke, toxic fumes, or corrosives produced when burning.
- Cold temperatures – Certain materials become brittle, lose flexibility, or otherwise degrade.
Cable jacketing and wire insulation choices are the #1 factor of success or failure relative to heat and cold:
Silicone, fiberglass, PVDF,
PVC, Neoprene, SBR
Thermoset materials, CEP (thermoplastic), FEP (Teflon), (PVDF), silicone
Thermoplastic elastomer (Santoprene),
PVC, polyurethane, polyethylene, rubber
“Highly resistant” is a relative term, so consult with your cable and wire distributor to best balance needs with budget. What’s “highly resistant” in an indoor appliance may not suffice for a military submarine.
5. Corrosion Resistance
Corrosion comes in many forms in an industrial environment: moisture, chemicals, oil, and UV light. To source a corrosion-resistant cable, consider:
- What corrosives may be present
- How much concentration (intensity) of the corrosive may appear
- How long exposure may last
The cable’s coating will be influential here, ideally keeping the assembly safe and reliable for years to come.
Hazards: Reduced insulation integrity, conductor corrosion, short-circuiting, electrical failure.
Solutions: TPU, cross-linked polyethylene (XLPE), polypropylene
Hazards: Corrosion, loss of mechanical and electrical properties
Solutions (depending on specific chemicals involved): FEP, PTFE, TPEs such as Santoprene
Hazards: Swelling, softening, degradation, loss of electrical properties, failure
Solutions: Polyurethane, EPR, silicone rubber
Hazards: Degradation and deterioration of insulation, reduced electrical performance, brittleness, insulation failure
Solutions: XLPE, TPE, EPR
This one’s about efficiency of production.
- Will the wire require processing such as stripping or cutting?
- Will processing be done by hand or with an automated machine?
- Will your desired cabling be easy to strip or terminate?
Consider the strippability of potential cable purchases to save time and effort during production, installation, and repairs. The last thing you want is to automate a process, only for the production line to slow to strip each wire entering the machine.
Some cables have specially designed insulation that allows for effortless stripping.
- EPR (ethylene propylene rubber)
- Other thermoplastics
Note that the hardness of certain materials, like PVC, may differ between manufacturers and affect ease of processing. Different equipment may produce different results, but making machine adjustments can typically accommodate these variations.
Price shouldn’t be the sole factor when buying control, supply, and other cables, but it’s an important consideration (unless your budget’s infinite).
Consider the needs of your design, your budget manager, and your customers:
- Specifications – Match your investment level to the caliber of voltage rating, flexibility, and length you need.
- Long-term performance – If you’re building equipment whose failure could result in catastrophe or death, don’t automatically buy the cheapest wire. Even in less-dangerous situations, it may be more cost-effective to buy expensive cabling that’ll last longer in rugged environments. Don’t forget to include maintenance and downtime costs.
- Sourcing partnership – Rely on a full-service distributor with experience in your market. It can recommend cheaper alternatives, prepare for demand spikes so you don’t overpay, and pass down bulk discounts.
Nobody wants to get ripped off, but when you’re sourcing heavy-duty cables, you need heavy-duty materials and engineering. Those come with a cost.
Ensure that the cable materials you spec are readily available in the quantities you need. Or, if they are obscure ones, at least use a distributor with a vast supplier network and track record of resourcefulness and preparedness.
This ensures easy replacements and expansions in the future, preventing unnecessary downtime and redesigns.
More Cable/Wire Buying Guidance
Even among industrial-specific cables, there’s an outrageous number of varieties to sort through. Assuming all options are available at a reasonable cost and lead time, focus your decision on:
- How mechanical & dimensional specs will affect usability
- How robust the electrical signal protection must be
- Environmental factors – temperature, moisture, & chemicals
Stick to those tenets and the eight tips above, and your cables and devices will exist in harmony – in any industrial application.
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