Consumable Feature: Water Cooled Cables - The importance of monitoring water & regular replacement.

Water-Cooled Cables: Keep the Lifeline of Your Plasma System Healthy

1. Why the water matters:

Water-cooled power cables do double duty - they carry hundreds of amps and whisk heat

away from the conductors. If the coolant isn’t up to spec, minerals and ions accelerate corrosion, create scale that chokes flow and, worst-case, let current leak through the liquid itself. That hurts arc stability and shortens cable life.

• Use de-ionized (DI) water or an OEM coolant mix. Conductivity should stay below about 5 µS cm-¹ (many OEMs allow 0.5–18 µS cm-¹) and be checked with a handheld meter at least quarterly.

• Never substitute automotive antifreeze. Its seal-plugging additives can block tiny torch passages.

  
  

2. Where voltage drop comes from (and why you feel it):

Every strand of copper in the cable has some resistance. As corrosion or strand breakage reduces the effective cross-section, resistance rises and you’ll see:

• Higher cable temperature and warmer return water

• The power supply reading a few volts lower at the torch than at its output lugs

• Extra current draw to maintain the same arc power

Today’s control systems flag these symptoms automatically; a rising voltage drop + hot return water is usually the first sign that the cable is on its way out. (i2power)

3. Monitoring checklist (monthly unless noted):

4. When to replace:

A water-cooled cable is a consumable. Pull it from service when any of the following hit:

1. Voltage drop climbs above about 5 % or rises steadily over several runs.

2. Outlet water is consistently >15 °F (8 °C) hotter than normal under the same load.

3. Conductivity tests reveal internal leaks (sudden jump in µS cm-¹).

4. Braided conductor strands show through the jacket, or you spot pin-hole leaks.

5. The cable feels noticeably stiffer (a sign the inner hose has collapsed or scaled over).

5. Best-practice tips:

• Filter first. A cheap 5 µm cartridge on the return line traps copper particles before they recirculate.

• Log numbers. Keeping a simple spreadsheet of conductivity, ΔT, and voltage drop turns “gut feel” into trend data—you’ll schedule replacement before an unexpected shutdown.

• Match current density. When ordering replacements, size the cable for ≤ 6 kA/in² and confirm you have enough flow (2–8 gpm, depending on size) to remove the heat.

Bottom line: Clean, low-conductivity water keeps resistance low and heat under control; routine monitoring lets you retire a cable on your schedule - not after it torches a production run.

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Remember, Thermach is not your competitor; your other options are. We don’t coat; we only supply thermal spray equipment and parts. You can proceed with confidence, knowing that our team is dedicated to creating a custom system that meets your exact specifications.

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Thermach manufactures thermal spray coating systems for the coating industry. We don't coat. We provide the equipment and parts necessary for you to run a successful coating operation. Our mission is to ensure your coating process is running smoothly with Thermach equipment.