3 Phase Kiln Retrofit....from 1PH to 3PH

Will just have to see how it goes after flipping the switch. With the crucible size I want run, might be just fine. In looking at the whole toolchain, waiting an extra 20-30 minutes during the first run could be time spent setting up CNCs on other jobs, making sure I have the right candles for the cast, yada yada

 

On Monday, I finished winding and installing the other 2 elements. Wired up elements to high temp wire via ceramic connectors then to the 3 phase SSR. Did the proverbially flip of the switch. Way quieter than my old elements; could barely tell they were on. Yesterday morning I did a temp test up to 1800 degrees with the kiln empty.

Real fast climbing right away
2:45 mins 750 deg
3:45 mins 1,000 deg
Climbing started to slow, due to heat-sink I'd imagine.
6 mins, 1250 deg
12:50 mins, 1630 deg
14:15 mins, 1700 deg
Just under 17 mins, 1800 deg!

Very happy with the results. Will be doing a charged melt here soon. I think the calculations that were made previously on this thread will be pretty close.

 

Measuring temp close to the center, on the bottom. Most likely where it is the hottest? 20 to 40 lbs of aluminum is typical for me. So is that like #6 to #20? I only use the graphites on for-profit casts. For the others I use my steel crucibles and recycled aluminum.

 

Great info Kelly! Thanks for sharing. Will have to step up my crucible game.

Oh....I have an idea for this!

The temp controller I have is an Omega branded one. It has run my solid state relays very well the years I have had it. Says it can run up to 6 furnaces at the same time. In the near future it will have the chance to try 2 sinultaneously.

I do have a kiln wiring question for the group. How would you guys attack this area. I know I need to have these live 3 phase wires covered but what is a good, simple solution?


Thanks!

 

Just an update. Made an okay metal cart for both kilns out of old bed frame angle iron. The furnace is working great, just have it wired up to a switch. About 45mins to an hour for the first charge then half-hour after that. The furnace is faster than I am right now for having LF molds ready to go.

Just flipping the switch and going is real nice.

 

Funny that you bring this up. Have been scouring the marketplace for various metal barrels and kegs to start down this path. Lots of the 55 gallon "burn barrels" for cheap around here. Kegs would be smaller but offer more rigidity.

Oh, the next step for this furnace is to make it lift off! That way I can switch up how I handle my crucibles so I can about triple/quadruple my pouring ability.

 

To give an update to readers passing through:

A good many heats were had from the retrofit. It was made lift-off via a welded-on backbone and an electric cable winch. With time the already too largely wound coils grew out of their too small of grooves and broke. Many tiny fixes and pin nails were put in place to get more heats out of the kiln. Alas, it now serves as my T5 heat treat kiln, firmly on the metal cart, with only the bottom element still working. Which, actually works well for heat treating.

It was replaced by a kiln that only had 4 heats on it that I got for $200.

It will most likely be used for bricks in my next upcoming resistive melting tilt furnace build.

Thank you for your service $120 FBMP kiln!