High voltage glass suspension insulators - Boulder, Colorado

I've never seen suspension insulators up close before so was a bit confused as to why there's so much metal in-between the glass (porcelain, ceramic?) discs? Obviously for strength since the high tension wires are heavy and create a lot of stress. Nevertheless, how do these things insulate so well - especially in wet weather?? I'll research the matter further and try to post an answer here.

This particular video recording in near the Valmont power generating facility in Boulder, Colorado. I believe the lines, in question, supply 230,000 volts but I'll have to double-check that as well. The insulators were lying on the ground immediately adjacent the Boulder Creek bike path.

Here's my personal web page about science, in general:
http://www.rogerwendell.com/science.html

05-12-2009

Category:

Science & Technology

Tags:

• high
• voltage
• suspension
• insulators
• power
• lines
• glass
• porcelain

[generator5500w]

yea i have 78 insulators at my home.... just different kinds

[zeekzilch]

@generator5500w

Excellent! Do you keep them on display or have a webpage about them?

[zeekzilch]

@generator5500w

What's you FB name and I'll take a look?

[TheChipmunk2008]

The main reason the metal 'appears' to be so close is that in fact the metal of one piece more or less encloses the other (with a layer of glass inbetween), so it's not relying on the glass for mechanical strength (in fact even with the glass broken away, they remain fully mechanically able to support the weight of the rest of the insulator string and conductor.

[zeekzilch]

@TheChipmunk2008

Thank you! That's the best explanation I've received so far - after having posted this two years ago! Your explanation makes sense but now I need to test it. I'll be on the look out for one of these surplus so I can bust it open or at least measure across it with a VOM!

[TheChipmunk2008]

@zeekzilch I actually have one out in the garden now (british manufacture but same concept, it's about 10 inches across). It's quite difficult to see the innards because the metalwork covers it all up, but I know the same concept of 'keep the glass or ceramic in compression' was used in lower voltage (600v or thereabouts) insulators for electric tramways and streetlighting in the first half of the 20th century

[zeekzilch]

@TheChipmunk2008

It would be especially interesting to observe the manufacturing process. I've been searching google for it but haven't found anything yet...

[generator5500w]

@zeekzilch yea my real name is cory benjamin beebe so u can find me

[generator5500w]

@zeekzilch yea i have display on facebook

[zeekzilch]

@MrSciencetificsasuke

Where did you get it from? Did you have to pay for it? If so, how much was it? I'd like to own one myself!