Pollution Performance Selection
Most insulator problems in service are contamination problems. Choosing a profile is not about buying the longest creepage figure; it is about matching the shed geometry to the deposit the line actually collects.
Start the ConversationFrom First Enquiry to Delivered Units
Each stage names the problem it exists to prevent, so you can see where your own project sits.
Characterise the Deposit
Problem. Sites are described as polluted without saying what the pollution is, so a salt-fog profile gets specified for a dust problem.
How we handle it. Salt, cement, agricultural dust and mine fines behave differently. We work from what the route passes and what the failure history shows.
Set the Specific Creepage
Problem. Creepage per kV is often copied from an earlier project rather than derived for the site.
How we handle it. The requirement comes from your pollution class assessment. We supply the per-unit creepage for every type so the unit count follows arithmetically.
Match the Shed Profile
Problem. A fog profile fills with fine dry dust; an aerodynamic profile has less nominal creepage; a standard profile flashes over in salt.
How we handle it. Fog profiles for salt and industrial fallout, double umbrella for fine dust with dew, aerodynamic for wind-cleaned remote sites, standard for clean inland air.
Check It Fits the Structure
Problem. The right creepage gives a string too long for the tower window or a shed too wide for the swing envelope.
How we handle it. Spacing and shed diameter are published per type so the geometric check is done before the order, not on site.
Questions About This Service
Is more creepage always better?
No. Nominal creepage only helps if the geometry keeps the leakage path open under the actual deposit. A fog profile that fills with dust performs worse than an aerodynamic profile with a shorter nominal figure.
How much does profile choice change string length?
Considerably. A 320 mm shed fog disc gives 550 mm of creepage per unit against 320 mm for a 255 mm standard disc, so the unit count for the same specific creepage nearly halves.
Can you review our existing string design?
Send the string drawing, system voltage and site conditions and we will tell you what the per-unit figures imply for the current design.
Put the Problem in an Email
Drawings, specifications and photographs of the installed hardware are the fastest way to get a useful answer.