Influence of Salt Environment on Aging

@TW: used in Maintenance Guides: DOCA0305 (MTZ with Mic Act), DOCA0099 (MTZ with Mic X), LVPED508016 (NT/NW)

Salt Environment

Influence	Appearance	Consequences
Corrosion of metal parts	Appearance of: White rust on zinc coatings Red rust on steel	Increase in friction Freezing of mechanism Broken springs Blocking of cores of MX/XF/MN voltage releases
Possibility of salt deposits on electronic circuits when thick salt mists occur.	Appearance of salt bridges on electronic boards	Potential failure of electronic systems due to short-circuiting of circuits, particularly non-varnished circuits.
Possibility of conducting salt deposits on the device when thick salt mists occur.	White deposit	Deterioration of device dielectric withstand resulting in possibility of phase-to-frame short-circuit and a phase-to-phase short-circuit if an overload occurs.

Influence

Appearance

Consequences

Corrosion of metal parts

Appearance of:

White rust on zinc coatings
Red rust on steel

Increase in friction
Freezing of mechanism
Broken springs
Blocking of cores of MX/XF/MN voltage releases

Possibility of salt deposits on electronic circuits when thick salt mists occur.

Appearance of salt bridges on electronic boards

Potential failure of electronic systems due to short-circuiting of circuits, particularly non-varnished circuits.

Possibility of conducting salt deposits on the device when thick salt mists occur.

White deposit

Deterioration of device dielectric withstand resulting in possibility of phase-to-frame short-circuit and a phase-to-phase short-circuit if an overload occurs.

Recommendations

The maintenance and installation recommendations according to the salt environment are defined in the following table:

Thresholds	Description	Maintenance recommendations	Installation recommendations
No salt mist	No influence	Implement the Intermediate program.	No particular recommendation
Moderate salt mist < 10 km (6.21 miles) from coast	Moderate aging of switchgear	Carry out more frequent periodic checks.	No particular recommendation
Significant salt mist < 1 km (0.621 miles) from coast	Rapid aging of exposed switchgear. On average, service life is divided by a factor of three for devices not installed in a switchboard.	Carry out more frequent periodic checks. Test the dielectric withstand every two years.	Install the switchgear in a switchboard or a room offering protection from the salt mist. Increase the switchboard IP value (IP54 is advised).