Buy now: Allen-Bradley 1756-PA72K ControlLogix Conformal Coated Supply
Atlantechdrives provides you the 1756-PA72K, the specialized «K» version of the standard AC power supply. This module is identical in performance to the PA72 but includes a factory-applied conformal coating. This protective layer is essential for automation systems installed in harsh, corrosive, or high-humidity environments where standard electronics would fail due to moisture or chemical exposure.
- Special Feature: Conformal Coating (K-Version)
- Environmental Rating: Resists salt spray, humidity, and corrosive vapors
- Input Voltage: 85-265V AC
- Output Current: 10A @ 1.2V, 4A @ 3.3V, 13A @ 5.1V, 2.8A @ 24V
- Standard Compliance: ISA-S71.04-1985 G3 Class
Why Conformal Coating Matters: The 1756-PA72K Edge
In industries such as wastewater treatment, pulp and paper, or chemical processing, atmospheric contaminants can cause «tin whiskers» or dendritic growth on exposed circuit board traces. The 1756-PA72K prevents this by sealing the internal electronics under a thin, transparent polymer layer. This coating provides a barrier against moisture, dust, and corrosive gases (like H2S or Chlorine). By choosing the 1756-PA72K, you are investing in a significantly higher Mean Time Between Failures (MTBF) for systems located in non-climate-controlled environments, ensuring that your power supply—the most vulnerable part of the rack—remains operational.
Installation Advice: Maintaining the Protective Barrier
When installing the 1756-PA72K, avoid touching the internal components or the backplane connector pins with bare hands, as skin oils can degrade the coating’s effectiveness over time. Ensure that the chassis you are using is also rated for the same environment (often denoted with a «K» suffix). It is a common mistake to use a coated power supply in a standard, non-coated chassis; for full protection, the entire system—including I/O and processors—should ideally be conformal coated if the atmosphere is classified as G3 corrosive.
Maintenance for Harsh Environments
Even with conformal coating, the 1756-PA72K requires specific maintenance. Periodically inspect the external terminals for signs of corrosion, as these metal parts cannot be fully coated. Use an approved electrical contact cleaner if you notice any green or white oxidation. Monitor the status LED; if the supply fails, do not attempt to open the casing, as breaking the seal of the conformal coating will void all environmental certifications. In G3 environments, we recommend replacing the module every 5-7 years as a preventive measure, even if it appears to be functioning correctly, to avoid sudden failures.
FAQs
Q: Is the 1756-PA72K compatible with standard 1756 modules?
A: Yes, it is electrically identical to the PA72 and fully compatible with all standard ControlLogix modules.
Q: What does the ‘K’ stand for?
A: In Allen-Bradley terminology, the ‘K’ suffix denotes that the product is conformal coated for harsh environments.
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