Freezer-Extension Lead Exclusion-Guarantee.

Whilst on the subject of plugs - which would you say had the largest contact area in terms of pin shape - round? (as in the old 15A types) or the present 13A square ones?

I think one of the old arguments in favour of square/flat pin plugs was that reliable contact area was greater - initially because it's far easer to manufacture two flat surfaces than two round ones of precisely the same radius (if the radius of the socket and pin differ even slightly the contact area shrinks very significantly) - and in service as things wear - a flat (worn by another flat surface) surface tends to remain relatively flat - whereas wear on circular ones tends to increase the radius on the socket contacts and decrease the radius of the pins.


   - Andy.

Whilst on the subject of plugs - which would you say had the largest contact area in terms of pin shape - round? (as in the old 15A types) or the present 13A square ones?

I think one of the old arguments in favour of square/flat pin plugs was that reliable contact area was greater - initially because it's far easer to manufacture two flat surfaces than two round ones of precisely the same radius (if the radius of the socket and pin differ even slightly the contact area shrinks very significantly) - and in service as things wear - a flat (worn by another flat surface) surface tends to remain relatively flat - whereas wear on circular ones tends to increase the radius on the socket contacts and decrease the radius of the pins.


   - Andy.