der5997 Posted March 30, 2014 Report Share Posted March 30, 2014 Hi, I've a question on the use of insulators we have in our museum's collection. We have two. These are small white ceramic, with a hole in the top presumably for accommodating a fixing nail. Both have U.S.A on the top together with similar, but not identical makers marks.WIS-P AND WIS-P-C Here's a couple of photos: and the underside: Any help you could give me in identifying the system these were used for would be helpful. They were recovered in 2003 from the inside of a building that had been a pool hall among other things in the village of Sheet Harbour, Nova Scotia. That building had been disused for some years. The electrical distribution system in Sheet Harbour was installed around 1923 as a by-product of the opening of a Ground-wood Pulp Mill at that time. Quote Link to comment Share on other sites More sharing options...
Erby Posted March 30, 2014 Report Share Posted March 30, 2014 They're insulators for knob and tube electrical wiring systems. More images & info on those systems here: https://www.google.com/#q=knob+%26+tube+wiring+images http://en.wikipedia.org/wiki/Knob_and_tube_wiring Quote Link to comment Share on other sites More sharing options...
rkenney Posted March 30, 2014 Report Share Posted March 30, 2014 Those insulators look like a common outdoor pole insulator. The wire wraps around the insulator. All the knob and tube I've seen, including this inspection from yesterday, the knob is two pieces and the wire is 'clamped' by the knob. Click to Enlarge 55 KB Quote Link to comment Share on other sites More sharing options...
Marc Posted March 30, 2014 Report Share Posted March 30, 2014 Electrical Inspection of Dwellings by Douglas Hansen has more info on that wiring method if you're interested. Shown in your photo is a 'solid knob'. Other components used in this system are the 'split knob' and the 'tube'. Marc Quote Link to comment Share on other sites More sharing options...
Bill Kibbel Posted March 31, 2014 Report Share Posted March 31, 2014 Both solid and split porcelain knobs were used for securing interior wiring. The split knobs are the more common in residential. The solid knobs required securing the wire with and additional wire twisted on and wrapped on the opposite side of the knob. It was short lived as the split-knob installation was much quicker. Click to Enlarge 44.16 KB According to the Pub, Insulators: Crown Jewels of the Wire, The knobs in the OP were manufactured by the Wisconsin Porcelain Co. in Sun Prairie, WI. Quote Link to comment Share on other sites More sharing options...
mjr6550 Posted March 31, 2014 Report Share Posted March 31, 2014 Looks like a knob for knob and tube wiring. The two-piece knobs seem to be more common. These were installed by running the wiring tangent to the groove and then a second piece of wire was wrapped around the groove and twisted onto the other wire at each side. This link may be of interest. http://www.docstoc.com/docs/159676740/T ... rchaeology Quote Link to comment Share on other sites More sharing options...
John Kogel Posted March 31, 2014 Report Share Posted March 31, 2014 Nice knobs, but where's yer tubes? [] Quote Link to comment Share on other sites More sharing options...
der5997 Posted April 2, 2014 Author Report Share Posted April 2, 2014 Those insulators look like a common outdoor pole insulator. The wire wraps around the insulator. All the knob and tube I've seen, including this inspection from yesterday, the knob is two pieces and the wire is 'clamped' by the knob. Click to Enlarge 55 KB Thanks, but these are one-piece, there's no detachable top with which to clamp the wire. Interesting photo though, do you mind if I use it when writing up the "Narrative" for these insulators? Quote Link to comment Share on other sites More sharing options...
der5997 Posted April 2, 2014 Author Report Share Posted April 2, 2014 They're insulators for knob and tube electrical wiring systems. More images & info on those systems here: https://www.google.com/#q=knob+%26+tube+wiring+images http://en.wikipedia.org/wiki/Knob_and_tube_wiring Thanks, but the tubes look longer and thinner that our insulators, and the squat ones you show are two piece, while ours are one piece. Any thoughts? Quote Link to comment Share on other sites More sharing options...
der5997 Posted April 2, 2014 Author Report Share Posted April 2, 2014 Both solid and split porcelain knobs were used for securing interior wiring. The split knobs are the more common in residential. The solid knobs required securing the wire with and additional wire twisted on and wrapped on the opposite side of the knob. It was short lived as the split-knob installation was much quicker. Click to Enlarge 44.16 KB According to the Pub, Insulators: Crown Jewels of the Wire, The knobs in the OP were manufactured by the Wisconsin Porcelain Co. in Sun Prairie, WI. Bingo! That looks like the solution - and thanks for the Manufacturer info as well. May i quote you in my "Narrative" for these insulators? Quote Link to comment Share on other sites More sharing options...
der5997 Posted April 2, 2014 Author Report Share Posted April 2, 2014 Looks like a knob for knob and tube wiring. The two-piece knobs seem to be more common. These were installed by running the wiring tangent to the groove and then a second piece of wire was wrapped around the groove and twisted onto the other wire at each side. This link may be of interest. http://www.docstoc.com/docs/159676740/T ... rchaeology thanks, and I'll read that .pdf later - it's lunch here now LOL Quote Link to comment Share on other sites More sharing options...
der5997 Posted April 2, 2014 Author Report Share Posted April 2, 2014 Nice knobs, but where's yer tubes? [] LOL - stuck in the joists I expect! If I ever get access tot hat buildnig again I'll take a look - now I know what I'm looking for. Thank you all for this excellent information. Quote Link to comment Share on other sites More sharing options...
Les Posted April 2, 2014 Report Share Posted April 2, 2014 I have a nice knob and tube collection in the basement that I used for classes. I could be persuaded to donate it to someone that could use it! Quote Link to comment Share on other sites More sharing options...
der5997 Posted April 3, 2014 Author Report Share Posted April 3, 2014 I have a nice knob and tube collection in the basement that I used for classes. I could be persuaded to donate it to someone that could use it! Les, that's indeed an interesting prospect. If you are so inclined, just one "Tube" would complement our two item collection. If you happen to have any provenance to accompany the tube you select, so much the better. (Age, Manufacturer, Location the tube was used in, that sort of thing.) We have very little available display space - these insulators sit on a shelf in our Museum Promo section next to the Visitor Information Centre. That section is house din what used to be a broom closet - so you maybe get the idea! If this Forum does Private Messages, PM me and we can push this forward. Do you have a PayPal account? If so you could invoice me - Postage and so - delivery address, those details. [:-thumbu] If not, I do have a $US account and could cut you a cheque. Quote Link to comment Share on other sites More sharing options...
Bill Kibbel Posted April 3, 2014 Report Share Posted April 3, 2014 Both solid and split porcelain knobs were used for securing interior wiring. The split knobs are the more common in residential. The solid knobs required securing the wire with and additional wire twisted on and wrapped on the opposite side of the knob. It was short lived as the split-knob installation was much quicker. Click to Enlarge 44.16 KB According to the Pub, Insulators: Crown Jewels of the Wire, The knobs in the OP were manufactured by the Wisconsin Porcelain Co. in Sun Prairie, WI. Bingo! That looks like the solution - and thanks for the Manufacturer info as well. May i quote you in my "Narrative" for these insulators? Sure. Quote Link to comment Share on other sites More sharing options...
Les Posted April 3, 2014 Report Share Posted April 3, 2014 I have a nice knob and tube collection in the basement that I used for classes. I could be persuaded to donate it to someone that could use it! Les, that's indeed an interesting prospect. If you are so inclined, just one "Tube" would complement our two item collection. If you happen to have any provenance to accompany the tube you select, so much the better. (Age, Manufacturer, Location the tube was used in, that sort of thing.) We have very little available display space - these insulators sit on a shelf in our Museum Promo section next to the Visitor Information Centre. That section is house din what used to be a broom closet - so you maybe get the idea! If this Forum does Private Messages, PM me and we can push this forward. Do you have a PayPal account? If so you could invoice me - Postage and so - delivery address, those details. [:-thumbu] If not, I do have a $US account and could cut you a cheque. will pm you and you feel free to pm me Quote Link to comment Share on other sites More sharing options...
der5997 Posted April 3, 2014 Author Report Share Posted April 3, 2014 Bingo! That looks like the solution - and thanks for the Manufacturer info as well. May i quote you in my "Narrative" for these insulators?Sure. Much appreciated Bill, Quote Link to comment Share on other sites More sharing options...
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