High voltage glass suspension insulators - Boulder, Colorado

[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?

[generator5500w]

@zeekzilch yea i have display on facebook

[zeekzilch]

@generator5500w

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

[generator5500w]

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

[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...

[MrSciencetificsasuke]

i just got one of those to day

[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!

[Dusty754]

The insulating property is the fact that any electricity would have to travel the entire surface length of the combined insulators to reach a ground. Thus it would have to travel from the cable around each "sombrero" in succession to a grounded point.

[zeekzilch]

@Dusty754

Thank you for the explanation. However, How deep does the center metal piece go into each glass "sombrero" and how are the metal pieces actually connected to the glass? Apparently there's some kind of mechanical glass connection to the metal or some adhesive or bonding agent that gives the entire string tremendous strength to hold up large amounts of wire in the air.

[Dusty754]

@zeekzilch

Best thing is to "google" high voltage insulators and go to the wikepedia site. This explains how they are made.

[soundseeker63]

@zeekzilch The metal is bonded to the glass with a kind of high strength cement and sealed with bitumen.

The steel cap on the top of the glass dish is hollow and the dish goes quite deep inside it. In the centre the metal pin to ling onto the next insulator is fitted whic is also cemented in.

[zeekzilch]

@soundseeker63

Thank you - that helps explain a lot about these types of insulators for me.

[Kashba777]

In Mexico we call "Aislantes"

[zeekzilch]

@Kashba777

Thanks! I think that translates to "Insulation."

[manman7039]

Hello, I need some of those disc insulation (U80BL) can you tell me where can I buy them??? or if you have a phone number of the store.

[zeekzilch]

@manman7039

Sorry, I don't know where you can buy these but I see a lot of distributors when I do a google search for "U80BL" - you might want to try that or see if others respond to your post. Best of luck!

[skater3050]

WOW BRAND NEW ONES.

[zeekzilch]

I would sure like to know how the metal is connected to each glass insulator without allowing the current/voltage to pass through? It appears as though the metal goes right through each glass plate but that can't be correct, can it?

[truthharbor911]

No, the metal does not go all the way through

[zeekzilch]

How does the metal stay attached to the glass if it doesn't go all the way through? Is the glass molded around the metal or is the metal simply glued somehow onto the glass? Thanks!

[truthharbor911]

the metal is cemented to the glass

[zeekzilch]

Any idea what kind of cement it is? I'd like to google it an learn more. Thanks!

[clearybeacon]

The glass is continuous, as you would expect. The cement is under compression, not tension. The metal parts, being the cap and pin are separate.

All suspension insulators have a maximum mechanical strength rating, in LB, or kN.

[zeekzilch]

@clearybeacon

I still don't understand how it could be a compression issue when the insulator is hanging in the air with the heavy weight of the wiring trying to pull the assembly apart? Do you know of a drawing or picture somewhere I could learn more? Thanks!

[djscrizzle]

@zeekzilch I'll bite... The part inside the metal caps are glass to. Strip away the metal, and you're left with a sombrero shaped piece of glass. The pin is typically bonded with either Lead (1930s Pyrex) or Portland cement. The insulators shown are Ball & Socket type.

They are meant for either dead-ending, or mid-span (a normal pole or tower) service, where they are always under strain. Clevis types exist, and you'll normally see these on neighborhood HV distribution & sub transmission lines.

[zeekzilch]

@djscrizzle

Thanks for the explanation! I think I understand it now but would love to take one apart for a closer look someday!