Ex. av skyddade kedjeisolatorer mot frätning
 
  Sediver skyddar mot frätning  
 

In certain environments, the insulator metal parts deteriorate with time due to electrolytic corrosion. This is particularly true in coastal areas, tropical climates and many polluted areas. In order to extend the service life of the insulators installed in such environments, Sediver offers several solutions to improve protection against corrosion:

Galvanising
All Sediver ferrous metal fittings are hot-dip galvanised.
IEC 60383-1 requires a zinc coating mass of 600 g/m² - or 85 µm. In severe conditions, where this standard protection is known to be insufficient, Sediver offers enhanced protection of the cap and the pin by increasing the thickness of zinc from 85 µm to 110 µm.

Pin - zinc sleeve
In severely corrosive marine and industrial atmospheres, and in all DC applications, the galvanised coating on insulator pins may deteriorate over time and be followed by corrosion of the pin itself. To prevent this form of pin damage, SEDIVER supplies - when needed - pins with a corrosion retarding sleeve made of high-purity zinc.
(The catalogue designation which identifies the presence of a zinc sleeve is "YC" or "ZC").

Zink skydd på kåp-pinn isolator

The sleeve is cast directly onto the pin and is partially covered by the cement. Its position and dimensions are designed so that the sleeve acts as a sacrificial anode and thereby protects the pin against galvanic action

  Zink skydd på kåp-pinn kedjeisolator
Standard pin Pin with corrosion
retardation sleeve
 
Cap - zinc collar
Sediver has developed and patented a cap which is protected by a cast-on collar made of high purity zinc. Sediver recommends its use for all HVDC applications and for HVAC applications in very corrosive marine and industrial atmospheres.
(The catalogue designation which identifies the presence of a zinc collar is "ZD" )

 

Electropic insulators
Sediver has developed a special range of insulators dedicated to perform in tropical environment.
The figure represents typical toughened glass optimised insulators used in tropical areas subjected to heavy contamination :

Zinkskikt skyddar kåp-pinn isolator

- to optimise the electrical stresses on the metal parts (cap and pin),

- to have a more uniform electrical field distribution on the insulator,

- to limit the effects of discharges around the metal parts during "wetted" periods.