Need Hi-Temp Wire for Oven

O

oldwolf

Joined
Dec 29, 2002
Messages
617
I'm finally finishing up my Mailbox Heat Treat Oven and need some Hi-Temp wire to go from the elements to the Relay. Where can I get this wire and connectors? A link would be nice.
 
A company "Omega" manufactured heat treat controllers and had an extensive line of associated supplies, remember this from the olden days befor I retired.

The high temp wire had some kind of high temp jacket.

Gene
 
Thanks guys. Budget casting looks like they have what I need to go from where the element wire exits to the relay in the controller box. Does #12 wire at 20 amps sound right? Seems a little lite to me.
 
oldwolf said:
Thanks guys. Budget casting looks like they have what I need to go from where the element wire exits to the relay in the controller box. Does #12 wire at 20 amps sound right? Seems a little lite to me.
Click to expand...
The amperage depends on the length and the gauge. 14 Kanthol A1 gauge will handle 20 amps. and last a long time. Its not like copper wire where you don't want it to heat up. I got 100 ft from (so I can have a spare element)
http://www.ec-securehost.com/PelicanWireCo.Inc./Miscellaneous_Requests.html
I see now they only list 20ft spools so you may have to call for longer lengths.
To figure out your amperage you need to know the ohms per ft of your wire. Available here http://www.resistancewire.com/mainpage.php?page=techinfo
To get 20 amps from 220V you need 11 ohms of resistance because Voltage divided by amperage equals resistance. To get 11 amps out of 14 gauge Kanthal A1 which has .213 ohms per ft you need. 51.6 ft. I run 50 ft fine. (I have a 40 amp SSR) If you go to 12 gauge you would need more wire to keep the amperage to 20 amps as it has less resistance so 12 gauge has .134 and you would need 82 ft and that's a lot of wire to get in your oven. 15 gauge has a resistance of .269 and it would take 40 ft.
15 gauge will take the amps, but the bigger the wire the longer it will last.
To get 50 ft of wire in my 22" x 4.5" x 4.5" oven I made my coils around a piece of 1/2" round stock. I turned the stock slowly in my lathe and taped the start end to the rod and then fed the wire on. My lathe has a 26" bed and I couldn't make it in one pass so when the rod was full I undid it and started again from the other end of the wire and made the coils meet. 14 gauge has an diameter of .064 That made about 360 coils and was about 2ft long before I stretched it. I stretched it to about 6' and run from a terminal in the lower back to the front up about 3: and the back and across the top of the rear back to the front and then down and back to the rear and my other terminal. Getting that much wire in is a challenge. It would help if you could use the ceiling but it would sag out easily. The coils must not touch each other. The wire works easily until you heat it up once then is brittle. You can work it after it has been hot by heating it to red and then forming while red hot. I made the grooves in my fire brick tight and then after the wire was in place I made a bunch of u shaped staples with legs about an inch long from some old kanthol wire.and pinned my coils to the fire brick every couple inches. My oven works great and I can hit 1850 for my D2 in well under 20 minutes from a cold start if I want. I plan to add a programable PID to it next so I can do better annealing of high alloy steels
 
oldwolf said:
Thanks guys. Budget casting looks like they have what I need to go from where the element wire exits to the relay in the controller box. Does #12 wire at 20 amps sound right? Seems a little lite to me.
Click to expand...
The amperage depends on the length and the gauge. 14 Kanthol A1 gauge will handle 20 amps. and last a long time. Its not like copper wire where you don't want it to heat up. I got 100 ft from (so I can have a spare element)
http://www.ec-securehost.com/PelicanWireCo.Inc./Miscellaneous_Requests.html
I see now they only list 20ft spools so you may have to call for longer lengths.
To figure out your amperage you need to know the ohms per ft of your wire. Available here http://www.resistancewire.com/mainpage.php?page=techinfo
To get 20 amps from 220V you need 11 ohms of resistance because Voltage divided by amperage equals resistance. To get 11 amps out of 14 gauge Kanthal A1 which has .213 ohms per ft you need. 51.6 ft. I run 50 ft fine. (I have a 40 amp SSR) If you go to 12 gauge you would need more wire to keep the amperage to 20 amps as it has less resistance so 12 gauge has .134 and you would need 82 ft and that's a lot of wire to get in your oven. 15 gauge has a resistance of .269 and it would take 40 ft.
15 gauge will take the amps, but the bigger the wire the longer it will last.
To get 50 ft of wire in my 22" x 4.5" x 4.5" oven I made my coils around a piece of 1/2" round stock. I turned the stock slowly in my lathe and taped the start end to the rod and then fed the wire on. My lathe has a 26" bed and I couldn't make it in one pass so when the rod was full I undid it and started again from the other end of the wire and made the coils meet. 14 gauge has an diameter of .064 That made about 360 coils and was about 2ft long before I stretched it. I stretched it to about 6' and run from a terminal in the lower back to the front up about 3: and the back and across the top of the rear back to the front and then down and back to the rear and my other terminal. Getting that much wire in is a challenge. It would help if you could use the ceiling but it would sag out easily. The coils must not touch each other. The wire works easily until you heat it up once then is brittle. You can work it after it has been hot by heating it to red and then forming while red hot. I made the grooves in my fire brick tight and then after the wire was in place I made a bunch of u shaped staples with legs about an inch long from some old kanthol wire.and pinned my coils to the fire brick every couple inches. For the terminals I ran 5/16" stainless steel all thread thru the back of the oven and mounted them to some high temp electrical insullation board that was mounted a solid over an inch away from the back of the oven. The holes thru my metal exterior where oversized and packed with kaowool. I attached the elements with a nut on the inside by the fire brick then a washer then the element then another washer and a nut. I connected the outputs from my SSR the same way on the far side of the insulation board. I made a metal cover for this with lots of holes to help keep the heat down on this end of the terminals. I had tried drilling holes thru a ceramic tile from the hardware store as a insulation plate on the inside of the oven. When I went up to 2150 for some high alloy I actually melted the surface of the tile! My oven works great and I can hit 1850 for my D2 in well under 20 minutes from a cold start if I want. I plan to add a programmable PID to it next so I can do better annealing of high alloy steels
 
Gene Chapman said:
A company "Omega" manufactured heat treat controllers and had an extensive line of associated supplies, remember this from the olden days befor I retired.

The high temp wire had some kind of high temp jacket.

Gene
Click to expand...

Gene I am taking you at your word and marking your file in my computer as Retired from knifemaking.

A. G. email agr@agr3.com
 
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