You are wiring a new automated production line. The control cabinet is twenty feet away from the conveyor. Cables will run along cable trays, past hydraulic units that leak oil, and through areas where temperatures vary. You need a cable that won't crack after six months, won't pick up electrical noise from nearby VFDs, and won't require expensive conduit for the entire run.
This is where industrial control cable, specifically TC-ER cable, becomes the right choice. This buying guide walks you through the decision step by step.
1. What Makes a Cable "Industrial Control" vs. Ordinary Building Wire?
Ordinary building wires like THHN are designed to sit inside conduit, in dry walls, with minimal movement. Industrial control cables live a harder life. TC-ER cable, which stands for Tray Cable with Exposed Run rating, is built for these conditions.
Key differences include:
- Insulation – XHHW-2, a cross-linked polyethylene material, is standard. It stays flexible in cold weather, resists oil and chemicals, and is rated 90°C in both dry and wet locations.
- Jacket – A black PVC jacket resists sunlight and general industrial fluids.
- Exposed run rating – TC-ER can be installed without conduit in cable trays and exposed locations, saving labor and material.
- Shielding options – Available with overall foil shield and drain wire to block electromagnetic interference.
For automation systems, where sensors, PLCs, and drives communicate continuously, these features directly affect uptime.
2. Three Common Control Cable Specifications for Automation
The right gauge and construction depend on signal type, distance, and environment. Here are three typical configurations.
12 AWG 4/C Shielded TC-ER Cable for Control Circuits and Sensors
- Use for – 24V DC sensor wiring, PLC input/output signals, encoder feedback.
- Why 4/C – Three conductors for signal and common, plus an insulated ground for noise drain.
- Shielding – Overall foil shield prevents EMI from nearby power cables.
- Typical application – Connecting a remote I/O panel to a main PLC cabinet in a bottling line.
8 AWG 3/C with Ground Unshielded TC-ER Cable for Motor Control and Power Feeders
- Use for – Small motor starters up to 10 horsepower, control transformer primaries, panel feeders.
- Why 8 AWG – Carries up to about 50 amperes, enough for many auxiliary motors in automation cells.
- No shield – Acceptable when run in a dedicated tray away from VFDs or sensitive signals.
- Typical application – Feeding power to a conveyor drive motor from a local control panel.
350 kcmil Unshielded TC-ER Cable for Main Automation Power Feed
- Use for – Main distribution from a motor control center to large automation panels or multi-motor control centers.
- Why 350 kcmil – Handles high current in the range of 200 to 300 amperes for entire production cells.
- Unshielded – Cost-effective for pure power; signal circuits handled separately.
- Typical application – Feeder from a substation transformer to an automation control room panel.
When ordering, always specify XHHW-2 insulation and UL listed TC-ER cable. Look for the TC-ER marking on the jacket.
3. Shielded or Unshielded? A Common Decision Point
Automation systems mix power and signals in the same tray, creating a risk of electromagnetic interference, or EMI. Here is how to decide.
- Analog signals such as 4-20 mA loops and thermocouples – Use shielded TC-ER cable with foil and drain wire to prevent noise from corrupting measurements.
- Digital I/O such as 24V DC and proximity sensors – Short runs under ten feet may be fine with unshielded cable; longer runs need shielding.
- Power to motors, heaters, lights – Unshielded cable saves cost because no sensitive signals are present.
- VFD motor leads – Shielded cable with overall shield reduces radiated emissions from PWM waveforms.
Customer pain point: A plant integrator once used unshielded control cable for analog flow sensors running parallel to VFD cables. The 4-20 mA signal fluctuated randomly, causing batch quality issues. The fix cost more than using shielded cable from the start. Our tip: when in doubt, add shielding.
4. Why XHHW-2 Insulation Matters for Automation Environments
Automation cables often run through washdown areas, near hydraulic oil, or in unheated buildings. XHHW-2 insulation offers three practical advantages.
- Wet location 90°C rating – Unlike THHN, which derates to 75°C when wet, XHHW-2 maintains full ampacity in damp or wet conditions.
- Oil and chemical resistance – Resists deterioration from lubricants, coolants, and cleaning agents common in factories.
- Cold flexibility – Remains pliable down to minus 40 degrees Celsius, so winter installation does not require pre-heating.
For food processing, automotive assembly, or chemical plants, this translates to years of reliable service instead of premature jacket cracking.
5. Exposed Run (TC-ER) – The Installation Advantage
Traditional tray cable, labeled as TC only, requires conduit for any run not inside a covered cable tray. TC-ER changes that. The ER stands for Exposed Run.
You can install TC-ER cable in:
- Open cable trays
- Cable ladders
- Along equipment surfaces with proper support
- Exposed outdoor or indoor locations
Benefits for automation projects:
- Faster installation – No pipe bending, no pulling through conduit.
- Easier retrofits – Add new sensors or control points without adding conduit runs.
- Lower material cost – No EMT, rigid conduit, or fittings.
Selection reminder: Do not assume all tray cable is TC-ER. Look for "TC-ER" printed on the jacket. TC-only cable still needs conduit for exposed runs.
6. Step-by-Step Guide to Selecting Your Industrial Control Cable
Follow these five steps when specifying cable for an automation system.
- Step 1 – Identify signal or power type. Analog, digital, or pure power? Analog almost always needs shielding.
- Step 2 – Check environmental exposure. Oil, water, sunlight, outdoor? Choose XHHW-2 insulation and UV-resistant black PVC jacket.
- Step 3 – Estimate distance. For runs over 100 feet, consider upsizing one gauge to manage voltage drop. Consult ampacity tables.
- Step 4 – Determine conductor count. Power: 3 conductors + ground. Control: 4 or more conductors. Include a spare pair for future expansion.
- Step 5 – Verify TC-ER marking. If exposed run installation is needed, ensure the cable is marked TC-ER.
FAQ
Q1: Can I use TC-ER cable for both power and control in the same run?
Yes, as long as the cable construction includes appropriate insulation for both purposes. However, avoid running very sensitive analog signals in the same cable as high-power VFD outputs. Use separate shielded cables for signals.
Q2: Is XHHW-2 required for TC-ER cable?
No, it is not required by the TC-ER rating itself. However, XHHW-2 is the most common insulation because of its wet location 90°C rating and durability.
Q3: How do I know if a cable is sunlight resistant?
Look for "Sunlight Resistant" or "UV Resistant" marked on the jacket. A black PVC jacket alone is not a guarantee.
Q4: Does GERTEL supply TC-ER cable for automation systems?
Yes. We manufacture UL listed TC-ER cable with XHHW-2 insulation in 12 AWG, 8 AWG, 350 kcmil, and other gauges. Shielded or unshielded, with black sunlight-resistant PVC jacket. Contact us with your specifications.
Q5: What is the difference between TC-ER and ITC-ER?
ITC-ER is for low-voltage, limited-power circuits below 150 volts. TC-ER handles power and control up to 600 volts or 1000 volts. For automation control panels, TC-ER is the usual choice.
Need a Quote for Your Automation System?
Our industrial control cables are manufactured under strict quality controls and carry UL certifications relevant to their construction. The TC-ER cables featured in this guide are UL 1277 listed for tray cable with exposed run rating. Additionally, our XHHW-2 insulated conductors meet UL 44 requirements for thermoset-insulated wires. These certifications ensure compliance with North American safety standards. For specific UL file numbers or to request our certificate, contact our technical team.
Tell us your conductor count, gauge, shielding requirement, environment (indoor, outdoor, oily, wet), and total length. We will recommend the right industrial control cable and provide a competitive quote.
Contact us
Dongguan Greater Wire & Cable Co., Ltd.
Tel/WhatsApp/Wechat: +86 136 6257 9592
Tel/WhatsApp/Wechat: +86 135 1078 4550
Email: manager01@greaterwire.com
Website: www.greaterwire.com