If you’ve ever stood in a manufacturing plant at 2 a.m., watching a line of machinery hum through a critical production run, you know how easy it is to take the quiet work of control and special cables for granted. I’ve spent the last 12 years sourcing, testing, and installing these cables for everything from food processing lines in rural Ohio to offshore wind farms in the North Sea, and the one lesson that’s stuck with me more than any other is this: a cable that seems fine on the spec sheet can fail catastrophically if it’s not built to withstand the corrosion it’ll face in the real world. As someone who runs a control and special cables supplier, I don’t just sell wire and insulation— I sell reliability, and corrosion resistance is the backbone of that. Let me walk you through what makes control cables different from special cables, how their corrosion resistance properties work, and why that matters for your operations. Control And Special Cables
First, let’s get clear on what we’re talking about, because the terms “control cable” and “special cable” get thrown around a lot, and mixing them up is a costly mistake. Control cables are the workhorses of industrial automation: they carry low-voltage signals to sensors, motors, and relays, telling a conveyor when to speed up, a valve when to open, or a batch tank when it’s full. They live in a lot of environments, but most often they’re exposed to mild to moderate stress— slight humidity, occasional dust, maybe some mild chemicals from cleaning processes. Special cables, though, are built for the extremes. These are the cables that go into coastal refineries where salt spray is constant, mining sites where acidic runoff seeps through equipment enclosures, or high-temperature furnaces where even standard insulation would melt in weeks. Their corrosion resistance isn’t just a “nice to have”— it’s a non-negotiable performance requirement.
Let’s start with control cables’ corrosion properties, because that’s where most of our customers first come to us confused. A few years back, we had a customer in a meat processing plant call us in a panic— their old control cables were failing every six months, and unplanned downtime was costing them $150,000 a day. When we pulled the bad cables to test them, we found the copper conductors inside had corroded so badly that the signal lines were fraying and breaking. What was going on? Their old cables had generic PVC insulation, and the facility used a lot of acidic, ammonia-based cleaning solutions. Over time, those fumes seeped through the PVC, reacted with the copper conductors, and created a thin layer of copper oxide that increased resistance until the signal cut out. That’s the thing about control cable corrosion: it’s often slow, insidious, and easy to miss until it’s too late.
The good news is that modern control cables are engineered to fight that. The most common corrosion-resistant feature we specify for standard control cables is tinned copper conductors. Tinning is exactly what it sounds like: a thin layer of solder (usually tin) is applied to the copper wire during manufacturing. Tin is naturally more resistant to oxidation and mild chemicals than bare copper, so it acts as a barrier between the copper core and any corrosive elements that get through the insulation. We also use PVC compounds with added stabilizers for control cables that will be exposed to mild chemicals or high humidity— not all PVC is the same. Our standard control cable PVC formulations include heat stabilizers that break down at a much slower rate when exposed to acidic or alkaline fumes, and they also have water-repellent additives that prevent moisture from seeping into the conductor strands.
But control cables aren’t one-size-fits-all. For example, control cables that go into outdoor enclosures, like those used for garden sprinkler systems or small solar farm monitoring, need a little extra corrosion protection. We offer a hybrid control cable that combines tinned copper conductors with a cross-linked polyethylene (XLPE) insulation layer. XLPE is far more chemically resistant than standard PVC, so it can hold up to months of UV exposure, light rain, and even contact with garden fertilizers without breaking down. Last year, we installed 2,000 feet of these XLPE-insulated control cables for a 50-acre apple orchard’s irrigation system, and when we checked in after a year, there was zero sign of corrosion— something the orchard’s previous cable supplier couldn’t promise, as their generic control cables would corrode within 18 months.
Now, special cables are a whole different ballgame, and their corrosion resistance is tailored to the specific extreme environment they’ll face. Let’s use that coastal refinery example I mentioned earlier. Saltwater and salt spray are some of the most corrosive substances on Earth— they create an electrolyte solution that speeds up galvanic corrosion, where two different metals in contact create an electrochemical reaction that eats away at both. Standard copper conductors would fail in months here, so we use two main approaches for these marine-grade special cables. First, we use nickel-plated copper conductors, not just tinned. Nickel is far more resistant to saltwater and strong chemicals like hydrocarbons and sulfur dioxide, which are common in refineries. Second, we use a thermoset elastomer insulation called EPDM (ethylene propylene diene monomer) that’s resistant to both saltwater and oil, and it has a closed-cell structure that blocks moisture from penetrating the cable core.
We also do a lot of work with mining companies, which face a different kind of corrosion: acidic runoff from ore processing. This runoff has a low pH, often around 3 or 4, and it can seep through concrete, steel, and even generic cable insulation. For mining special cables, we don’t just rely on plating— we use copper-clad steel (CCS) conductors for heavy-duty applications, or even stainless steel conductors for cables that will be fully submerged in acidic water. The stainless steel adds incredible corrosion resistance, and we pair it with a cross-linked chlorosulfonated polyethylene (CSPE) outer jacket, which is resistant to both acids and abrasion from rock and equipment. Last year, a coal mining client told us their previous cables would corrode so badly after six months that the jackets would split, and water would get in, shorting the conductors. The CSPE-jacketed, stainless steel conductor cables we installed for them 18 months ago are still running without any signs of corrosion— that’s a game-changer for a mine where a single failure can shut down an entire section of production for weeks.
Another big category of special cables is high-temperature cables, which are used in furnaces, kilns, and power generation plants. At temperatures above 200°C, even tinned copper starts to oxidize rapidly, and PVC insulation melts. For these applications, we use magnesium oxide (MgO) insulated special cables. MgO is a ceramic material that’s not only heat-resistant up to 1000°C, it’s also completely corrosion-resistant to acids, alkalies, and moisture. The conductors inside are usually nickel-chromium alloy, which holds up to high temperatures without corroding, and the whole cable is sealed with a stainless steel outer sheath that acts as an extra barrier. We installed one of these MgO cables for a glass manufacturing plant that was having issues with old cables corroding when they were exposed to the high-temperature, acidic fumes from the glass furnaces. The old cables would fail every 12 months, but the MgO cables we put in three years ago are still going strong.
I get a lot of customers asking me: “Can’t I just buy a generic cable and add a corrosion coating later?” Let me be clear: that’s never a good idea. Adding a coating after manufacturing can create gaps or thin spots where moisture or chemicals can seep through, and it also adds extra bulk and flexibility issues, which matter a lot when you’re routing cables through tight spaces or moving machinery. The corrosion resistance of control and special cables is built into every layer— the conductor plating, the insulation formulation, the outer jacket material, and the overall design— and there’s no shortcut to that.
Let’s also talk about the unseen corrosion that’s not from chemicals or salt: galvanic corrosion from improper installation. I’ve seen so many cases where a perfectly good cable installed by an unqualified technician fails just because it’s run too close to a steel pipe, or another metal that’s more reactive. For example, if you run a standard copper control cable alongside a steel water pipe that’s exposed to moisture, the copper and steel will create a galvanic cell, and the copper will corrode over time. That’s why as a control and special cables supplier, we don’t just sell cables— we offer free consultation to help customers design their cable routing, pick the right conductor plating, and choose the right insulation for their exact environment. Last year, a customer was about to install a set of control cables alongside steel support beams in a new warehouse, and we caught that potential galvanic corrosion risk by suggesting a nylon spacing barrier between the cables and the beams. That small change saved them from a potential $20,000 replacement and downtime.
When it comes to testing corrosion resistance, we don’t just rely on manufacturer specs. Every batch of control and special cables we sell goes through our own in-house salt spray test, which exposes the cables to a fine salt mist for 1,000 hours (that’s equivalent to about 10 years of coastal exposure) and then checks for conductor corrosion and jacket degradation. We also do immersion tests where we submerge cables in solutions of different pH levels to simulate acidic or alkaline environments, and we test them at high temperatures to make sure the insulation doesn’t break down and the plating stays intact. For custom special cables, we can even run field tests with small prototype batches installed at the customer’s site for 6 months before full production, so we know exactly how they’ll perform in their specific environment.
I think a lot of people in the cable industry overcomplicate corrosion resistance with technical jargon, but at the end of the day, it’s about one thing: keeping your operations running. A control cable that corrodes is a production line that stops. A special cable that corrodes is a maintenance team working overtime to replace cables at 3 a.m., or a whole offshore rig shutting down because a signal line failed. That’s why we spend so much time perfecting our corrosion-resistant designs— we’ve had customers switch to us after losing $2 million in a year to unplanned downtime from corroded cables, and that’s the kind of impact that matters more than any spec sheet number.
If you’re dealing with corroding control or special cables, or if you’re planning a new project in a harsh environment and want to make sure your cables will hold up, I’d love to talk through your needs with you. We work with small manufacturing plants and large global energy companies alike, and every cable we design is tailored to your specific environment, not a one-size-fits-all solution. Don’t let corrosion turn your downtime into a monthly expense— reach out to discuss your cable needs today.
Aluminum Alloy Cable References
- Underwriters Laboratories. (2022). Standard for Control Cables and Signaling Wires. ANSI/UL 62.
- International Electrotechnical Commission. (2021). Corrosion-Resistant Cables for Industrial and Marine Applications. IEC 60227.
- National Electrical Manufacturers Association. (2020). Standard for Special Purpose Cables for Harsh Environments. NEO 38-2020.
- ASTM International. (2019). Standard Test Methods for Salt Spray (Fog) Testing. ASTM B117-19.
- IEEE Standards Association. (2021). Corrosion Mitigation for Electrical Cables in Industrial Facilities. IEEE Std 1580-2021.
Hebei Fengbo Electrical Equipment Co., Ltd.
Address: No.100 meters south, East Ring Road & Wei’er Road intersection, Huang’erying East Village, Jiajiakou Town, Ningjin County, Xingtai City, Hebei Province, China
E-mail: fonbocable@gmail.com
WebSite: https://www.fonbocable.com/
