Cubic Kiosk Enclosure: Corrosion Analysis and Mitigation... | terminalfaults.org

Technical Background:

The system operates on 24V DC logic. Water ingress can cause electrolytic corrosion, leading to increased resistance in circuit paths. This elevated resistance can reduce voltage levels to critical components such as bill validators and solenoids, resulting in operational failure. Corrosion also impacts grounding, creating voltage potential differences and ESD sensitivity.

Symptoms:

Observed corrosion on internal components of the Cubic enclosure. Reported failures include bill validator malfunction and solenoid-related jams. Fault recurrence is weather-dependent, increasing after precipitation.

Possible Causes:

Compromised enclosure seals allowing water ingress.
Degradation of corrosion-resistant coatings on internal components.
Accumulation of condensation due to temperature fluctuations (-40C to operational).
Galvanic corrosion between dissimilar metals within the enclosure.
Damage to cable entry points, creating paths for water to enter.
Failed or improperly installed drain plugs or vents, trapping moisture.

Solution:

1

Power down the kiosk and disconnect from mains power. Follow Lockout/Tagout (LOTO) procedures.
2

Perform a thorough visual inspection of the enclosure seals and cable entry points for cracks or damage.
3

Check drain plugs for blockage and ensure proper vent functionality.
4

Use a calibrated multi-meter to test for voltage drops across corroded components (validator, solenoids). Record measurements.
5

Apply a corrosion inhibitor spray to affected areas, ensuring compatibility with electronic components.
6

Replace any severely corroded components, such as connectors or wiring harnesses.
7

Verify proper grounding and bonding to minimize galvanic corrosion potential.

Safety Warning:

High voltage circuits are present within the enclosure. Always follow Lockout/Tagout (LOTO) procedures before performing any maintenance. Wear appropriate personal protective equipment (PPE), including safety glasses and gloves. Ensure the work area is dry and well-ventilated.

Prevention:

Conduct routine inspections of enclosure seals and cable entry points every six months. Clean any accumulated debris and apply a sealant to compromised areas. Periodically check drain plugs and vents for proper functionality. Consider installing a desiccant pack inside the enclosure to absorb moisture.

Expert Tip:

Use a thermal camera to identify areas of significant temperature differentials within the enclosure. These areas are prone to condensation and subsequent corrosion. Apply conformal coating to exposed circuit boards to provide an additional layer of protection against moisture.

Frequently Asked Questions

•What type of corrosion inhibitor is recommended for the internal components?

A non-conductive, electronics-grade corrosion inhibitor spray is recommended. Ensure compatibility with plastics and metals used in the system.

•What is the expected lifespan of the enclosure seals in a harsh climate?

The lifespan of the enclosure seals is dependent on environmental factors, but typically ranges from 3-5 years. Regular inspection and replacement are crucial.

•How can galvanic corrosion be mitigated in an enclosure with dissimilar metals?

Galvanic corrosion can be mitigated by using sacrificial anodes, applying dielectric coatings, and ensuring proper grounding and bonding.

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What type of corrosion inhibitor is recommended for the internal components?

•What is the expected lifespan of the enclosure seals in a harsh climate?

•How can galvanic corrosion be mitigated in an enclosure with dissimilar metals?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: