Here you go - http://www.ifi-inc.com/Products/Ribbon_Elements.php They usually fit in grooves in the fire brick furnace lining. The ribbons have pretty much replaced the old coiled wire elements.

 

Sorry for the delay, I finally had to make a trip to the REC in order to get the schematic that you guys were wanting to see.
This drawing is the same as at my shop except mine is underground, where this drawing is on a pole.
The next scan is from Trent Inc. to show you what my elements resemble.
The material I have was originally coiled flat in 12" loops over 1" diameter ceramic insulators and were about 80' long, per coil ( 3 coils total) with 5/8" diameter pigtails that were about 18" long.
The pigtails are the rods that the load wires are connected to.
I built a fixture to form them like the Trent design.
If you want to see my fixture and the coils I fabricated, I can do that also.
The resistance reading on my coils are .5 ohm.
I had them spaced apart with insulators, no shorts caused.
I have rewired the 480 transformer with a 225 amp, 800 volt breaker and 4/0 wire, but have not put a load on it.
The REC suggested this because the secondary side is 240 volt, 190 amps and my wiring and fuses were too light.
I checked the coils in the transformers, no shorts,
Not to bore Wayneh, or question his statement about overestimating the members of this forum but I had sent a schematic as requested, apparently it wasn't professional enough so I took the slap and called it a dummie type.
I'm not as well versed as some of you, that's why I came here to learn, it's that simple to me.
To Gerty, the coils are not marked, but if you order new ones, they come tagged and are designed by size and length (wall load) to the voltage you want to power with.
As shortbus mentions, the old way was heavy round wire, which required step down transformers because of the low resistance which is stated by Trent furnace Inc.
I pulled a transformer off the shelf last week for another test.
This small transformer, about 40 pounds was rated at 200v primary and 33v,45A secondary.
I connected two hot legs from a 240v, 60A single phase line to the primary side and this gave me 41.6v on the secondary.
I attached the two taps to each end of one of my coils and it was coming into a red state drawing 150amps.
Within 10 minutes, the heat was starting to discolor the insulation at the tap, so I shut it down.
Now I'm sure you might think that one coil at 41.6 would be the same as 3 coils in series at 120v, but that has already been tried and does not work in this case.
Maybe it has something to do with inductance, or impedance?
We can drop this thread and forget it ever happened, but I wanted to be sure you guys could see the schematic of the

 

Looking at your PDF drawing, the old familiar WTF alarm starts going off again, but this time I know it's because of my own lack of knowledge. You came here to learn but you're teaching me. I can't believe this is legit; seems like a huge kludge to me. But, now my mind is abuzz. I wonder if I can use this type of setup to turn my 240V single phase service into 3 phase....

Anyway, throughout this whole thread I was under the misunderstanding that you were the one who had set up these transformers. that being said, I need to go back to the beginning of the thread and re-read everything so I have a firm grasp on what the problem actually is ( I have a bad memory), and what the solution might be. I don't have time to do that tonight. So tomorrow sometime around 6PM I will probably post again. if I don't, post again so this thread shows up in my subscribed threads as a reminder (I might forget). or maybe someone will have answered your question by then.

 

I think the whole problem is on the PDF, toward the bottom of the page, left side. Where it says "Applications" and "Bank Rating". Basically says not to be used for big three phase loads. A new electrical service may be in your future.

Unless you can rewire the furnace for single phase.

 

Strantor
I just spent almost two hours typing it all down and loading the pictures and this system required me to re log in and it ate the whole thing.
I'm toast.

 

So, could we get a quick review of the situation?
As in what power supply do you have and what voltage and current do the elements require?

The fact that the fuse was blowing without load might have somtheing to do with you having a split phase supply and feeding it to a transformer bank that expects two phases out of a 3-phase system.

 

I'm sorry man, I know I've really fallen down on this thread. I haven't had the time to sit down for more than 30 min at a time ro re-read it. I keep going back to the beginning and then get pulled off to something else. So, since I've read post #1 so many times, I keep coming back to this:

I have 57.5 volts phase to phase, drawing 90 amp from room temperature, up to around 750 degrees in 15 minutes and that's as high as it goes.

So, all your coils have continuity, no shorts, same resistance reading, and same amp draw (which is also the correct rated amp draw). This seems to indicate that they're all "good" despite having babbit dripped on them, and it seems to indicate that they're getting the proper power. If it only goes up to 750 degrees, then maybe that's all it's capable of. I don't really see a way around that; if they're all drawing the proper amps then they're all dissipating the proper heat, according to ohms law - no need to look any further than that. I can't conceive a scenario where improper transformer connections or anything would trump it.

 

Have you checked the controls of the furnace? If the controller is bad and not working wouldn't that cause the problem? What happens when the control is bypassed?

If the wrong type of thermocouple is used on a controller it will give false signals to the controller. Thermocouples for different temps give different voltages to the controller. Controllers and thermocouples have to match.