annealer wiring diagram?

[Rick Wilton]

either I've forgotten how to read a schematic or what?

The way I read the drawing the SSR is only going to the MDR controls to turn the MDR on and off. Yes there is a door switch but it is not connected to the SSR at all.

What am I missing?

[Dennis Hetland]

First of all there is no such thing as 220/110 volt service in the US anymore. It's 240/120. Maybe that wiring diagram says it. If it does it must be really old.
Second the leakage from a solid state relay is micro and not the safety issue. The safety issue is that an ssr is a single pole switch and only opens one leg of the 240. This stops the flow of current through the elements, but does not isolate them. If you were to touch the element when the ssr was open and be grounded ( be touching something that was grounded at the same time) you would get hit with 120 volts at twice the current/amps that your annealer normally runs at. The ssr may be open, but the other end of the element is still tied to a wire that is tied to a breaker in a panel. So if you touch it you're touching the breaker.
I'm sure the MDR in the wiring diagram is a 2 pole which would break both legs of the 240 and isolate the elements from any electrical connection.

To add fuel to the fire, the way I'm reading the print, something is screwed up. One side of the MDR coil (which is supposed to be fed by 120v) is fed from Line 1 or leg one through the microswitch. The other side of the coil is fed L2 or leg 2 power when the SSR is closed. This is wrong. My guess is that the print should show a connection from the 2/TI lead on the SSR down to the neutral leg. This would then tie in to the rating on the SSR & the Coil rating on the MDR. Still doesn't explain why he's using the SSR to fire the MDR instead of just putting in an SSR that's rated for the 220 load & directly switching the element power with the SSR leaving the MDR to break both legs of the 240V whenever the door is opened.

[Dennis Hetland]

I was reading this thread backwards. I found the diagram and it looks like his control voltage is DC and he's not concerned with element life. It's an annealer. So to control the MDR he used an SSR.
Maybe in the old days they had fewer options on controller and relay voltages.

[Pete VanderLaan]

Hey if you want old, check out that page 242 in glassnotes. It's probably stamped approved by Thomas Edison.

Originally Posted by Dennis Hetland

First of all there is no such thing as 220/110 volt service in the US anymore. It's 240/120. Maybe that wiring diagram says it. If it does it must be really old.

...or, derived from a schematic drawn by a Canadian, as it were.

Originally Posted by Dave Hilty

To add fuel to the fire, the way I'm reading the print, something is screwed up. One side of the MDR coil (which is supposed to be fed by 120v) is fed from Line 1 or leg one through the microswitch. The other side of the coil is fed L2 or leg 2 power when the SSR is closed. This is wrong. My guess is that the print should show a connection from the 2/TI lead on the SSR down to the neutral leg. This would then tie in to the rating on the SSR & the Coil rating on the MDR. .

Yeah Dave, I thought so too. Or the coil of the MDR should be 240v

[Pete VanderLaan]

Originally Posted by Eric Miller

...or, derived from a schematic drawn by a Canadian, as it were.

***********
From Alberta.

[Rick Wilton]

I didn't draw anything (if you mean me) . The schematic appears to be from the US, I just pointed out some strange (to me at least) things. Using a SSR (relatively high tech) to control a MDR (old school) You can't legally get MDR is many states or in Alberta.

Originally Posted by Rick Wilton

I didn't draw anything (if you mean me) . The schematic appears to be from the US, I just pointed out some strange (to me at least) things. Using a SSR (relatively high tech) to control a MDR (old school) You can't legally get MDR is many states or in Alberta.

Since the schematic was drawn by Drew Fritts, who is a member of CraftWeb...perhaps he will pop in here and explain it all into clarity for us?

[Pete VanderLaan]

This is the point where plausible deniability starts to get important....

First of all , I apologize because I didn't realize this thread had started posing questions about my wiring diagram and I hadn't been reading it.

1. The diagram is based on Mark Lauckner's design of a portable controller box. The plug on the left is a dryer cord that plugs into a standard dryer receptacle. That way the controller can be moved to power different units in the shop.

2. The two receptacles on the right side are an either/or situation. The 2-way switch controls which receptacle is powered. The reason for that setup is that I have some units that require 240v and some that require 120v in my shop. So, depending on which unit I'm controlling I simply throw the switch to turn on the appropriate outlet. I use an R-type thermocouple that stays connected to the controller and fits into each of my furnaces and annealers, so I simply move it to the unit I'm going to use. The lid switches have quick-connect plugs so the wires are disconnected at the lid switch and moved as well.

3. As for the distinction between 220/110 or 240/120 - I'm sorry for the confusion - I'll fix it.

4. Dave Hilty is correct that there is an error regarding the coil voltage for the MDR. In the diagram the coil voltage should actually read 240v. I have several different controllers - some with 120v coils and some with 240v coils. That was an oversight when I was printing the PDF file. I'll fix it. For a 120v coil the only change that is needed is to run 2/T1 from the SSR to neutral instead of the L2 power. I'll put a 120v version out there as well. Thanks Dave.

5. It has also been pointed out to me via PM that the diagram doesn't currently show a separate ground wire that can be used as a frame ground for whatever unit is plugged into it. I'll change the diagram to be a 4-wire plug with a separate ground wire for that purpose.


If you have other suggestions or questions I'll be sure to keep reading this thread for a while.

Originally Posted by Drew Fritts

First of all , I apologize because I didn't realize this thread had started posing questions about my wiring diagram and I hadn't been reading it. (SNIP) If you have other suggestions or questions I'll be sure to keep reading this thread for a while.

minor details aside, though..that is a really good diagram. The thread starter is correct that there really isn't a good wiring diagram in either of the two "holy grail" books for this stuff, and your diagram is one of the best out there.

Dave (Trent) attached is what I think you are looking for. Drew's improvements on the basic concept might make the whole thing confusing without something simpler for context.

But, do yourself a favor like I said and just buy Mark's CD. For the specific purposes of wiring a kiln, annealer, or wire melter, his CD is a much better resource than either GNotes/GBCompanion books.

His vids, plus the diagram I attach here should make the whole shebang pretty easy to address. (the diagram comes from Dudley's website, which is also a very good resource for all things electrical, if you can find your way around it. Book, not so much, website, yes)

hope this helps.

Thanks Eric...

I think I've fixed the problems mentioned so far... Here are the two new versions - one with a 120v coil and one with a 240v coil:

120v Coil Version

240v Coil Version

I removed the text at the top that specified that it was a 30 Amp control box because it's really independent of the breaker amperage. I run one of these on a 50 Amp furnace as well as several 30 Amp uints.

To clarify, for those of you who haven't seen one of these Lauckner-style controllers in person, EVERYTHING in the schematic (with the exception of the 240v plug on the left [which is a dryer pigtail], the thermocouple, and the lid switch) is contained in an 8 x 8 electrical box.

The advantages of this type of control box are that they are portable, they are plug-and-play, and the expensive parts (the thermocouple and the MDR) are only purchased for as many controllers as you want, not the number of units that you want to run. Obviously, this is only a savings if you have annealers, pick-up ovens, furnaces, warmers, kilns, etc. that you only want to run occasionally.

Another advantage of this design is that you can use whichever brand of digital controller you want. It doesn't have to be a Fuji as shown. It simply has to have a pulsed voltage output to run the SSR in this design.

[Pete VanderLaan]

I will move this thread to Antiques and Classics since it deals with such a fundamental issue. Nice work people!