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screen printing => Equipment => Topic started by: Gilligan on September 09, 2011, 11:35:25 AM
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So now onto the conveyor.
Chaparral 2412 (24" x 12') It has three 12x24 panels.
Only one was working. They had already purchased a replacement from Lawson that came completely framed up. (probably good because the other ones are all riveted in.
Only a couple of problems. They don't mount the same but I can get around that... right now it's just wedged into the space and has some "L" brackets that are about 1" from the supporting rail... so I just need to put a stand off in there for good measure.
The other problem is connecting them. The original panels just had high temp wires going into the panel (rather small gauge considering the draw)... however the new panel has this twisted metal pigtails coming out of it. Kind of like this (sorry the pic is crappy... I just pulled this off the web):
(http://img.directindustry.com/images_di/photo-m2/infrared-radiant-panel-456207.jpg)
Can't see from the pic but coming out of that ceramic donut is a hard wire that forms a loop.
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Hey Gilligan,
They should have purchased a replacement heater with leads on it! That is how we sell our replacement heaters, makes it so much easier for the customer to replace the element.
What you will need to do is use ring terminals with nuts and bolts. All hardware MUST be for high temperature use. We use High temp, crimp on ring terminals, and stainless steel #10 bolts and nuts. Measure the size of the hole in the strap before buying hardware though! Make sure the ring terminals you get are for the correct gauge wire, and have the same opening as the hole in the strap on the heater. That is a very common way for infrared panels to be manufactured.
Hope that helps!
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Thanks Mike.
So basically something like this:
(http://cableorganizer.com/outlet/panduit/image/Kgrpprht6-o.jpg)
And just run a stainless nut and bolt through the terminal on the panel and through this eyelet. Cut wires off old panel and crimp them in the crimp side.
Makes a lot more sense than any ideas I had. LOL
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Thanks Mike.
So basically something like this:
([url]http://cableorganizer.com/outlet/panduit/image/Kgrpprht6-o.jpg[/url])
And just run a stainless nut and bolt through the terminal on the panel and through this eyelet. Cut wires off old panel and crimp them in the crimp side.
Makes a lot more sense than any ideas I had. LOL
You got it! Just be sure that everything is stainless or says for high temp. Remember that can get to be 900deg +. I know some of our panels get to be around 1,000 deg f when we run them full bore on a strong 220V circuit.
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While I got the experts attention.
In the bottom "box" where the "breaker" is... the leads go through some "post" which are situated in this "ring". I'm assuming that is how it controls the flow of voltage to the panels?
The ground lead is wired to the "ring" itself on one side with a what I think is a cap in between the terminals on the ring. I assume this creates an electromagnetic field and those "post" are then allowed to pass the voltage through.
Did I get it right? and is this how most dryers are wired?
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While I got the experts attention.
In the bottom "box" where the "breaker" is... the leads go through some "post" which are situated in this "ring". I'm assuming that is how it controls the flow of voltage to the panels?
The ground lead is wired to the "ring" itself on one side with a what I think is a cap in between the terminals on the ring. I assume this creates an electromagnetic field and those "post" are then allowed to pass the voltage through.
Did I get it right? and is this how most dryers are wired?
Well, I hate to say that your description is tough to understand... But it is a little bit. Any chance you have a wiring diagram of the dryer? I could tell you what's going on if you did. Without it, I'd be merely speculating on what each of those items are.
Normally, the temperature of a dryer isn't controlled by varying voltage to the emitters, but by turning them on and off. Essentially, the dryer's "Set point" is reached by the controller sending full power to the emitters until the set point is close to the dryer's thermo reading. As it gets closer to the set point, the controller turns the heaters on and off to try and get the temperature to stay consistent. Many times, controllers must first "Learn" the system. Different controllers must be setup in different ways unfortunately.
When you see a controller that does not give feedback, like our flash units and entry level dryers, there is no thermo reading. If the controller is say 1-10, setting 1 will be on 10% of the time, and off 90%. At 9 it would be on 90% of the time and off 10% of the time. Many people may have flash units like this, and it is often times a good idea to warm up the flash on "HI" or "10" if that is an option, and once warmed up, throttle it back down to a lower number.
I know I went a little off track there in my explanation, but I figured I'd let you know how we control our heaters in our applications. I am really not experienced with other manufacturer's wiring techniques and wouldn't want to take a guess on what the National dryer's configuration is like.
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I'm trying to get the info from Dan at Workhorse but it seems like no one has a schematic. :(
I agree, my description sucks... *shrug* I'll get a pic tonight.
BTW, I said: controls the flow of voltage
for a reason... On and off is controlling voltage. :) I figured that it was off/on but I stated it in more ambiguous terms in case some did it differently.
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I'm trying to get the info from Dan at Workhorse but it seems like no one has a schematic. :(
I agree, my description sucks... *shrug* I'll get a pic tonight.
BTW, I said: controls the flow of voltage
for a reason... On and off is controlling voltage. :) I figured that it was off/on but I stated it in more ambiguous terms in case some did it differently.
Sorry.. I read your original post incorrectly. Controls the flow of voltage, I immediately thought of "Voltage regulator" or something of the like. Sorry for the misunderstanding! I'm also not an electrician, so maybe that assists in my misinterpretation of your description.. If you take a picture, I'll get our master electrician to check it out!
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No harm no foul. I knew when I typed it that it could be taken either way... so in a sense I laid out the "trap" :)
I was just there and KNEW there was something on that dryer I needed to do while I was there! DOH!
Couple more hours I'll have a pic.
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Took a pic tonight.
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It is a 3 pole(3phase) Mercury contactor.
If each panel has has 2 wire( 1 phase) on each panel, you will have to"balance the load",
on the contactor,with 2 wires on each pole of the contactor.
If using ring terminals,use only high temp, with stainless fasteners,covered in high temp fiberglass tape.
If wire to wire, use only ceramic wire nuts, wraped wit high temp tape!
Good Luck!
winston
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Actually it's wired in Single Phase... even is stamped so on the serial plate. I guess they are all setup for 3 phase and then made to work single phase for some of the models. *shrug*
Everyone's friendly neighborhood "buddy" actually was helpful when I bumped a thread on t-shirtforums asking for a service manual. He mentioned that it would be easy to wire it single phase. Apparently the control panels are single phase and they usually just put the panels in 3 phase. Obviously they (the panels) aren't that complicated, just dummy resistive loads. Putting them all on one phase (I only have single phase) isn't all that big of a deal.
That being said... it is probably moot point because you are still right... it's a 3 pole (3 phase) gadget.
But how does it work? (just curious now)
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Your photo is of a mercury relay. The way they work is when the coil is energized(the two leads where the blue piece is) the contact make by being immersed into liquid mercury. The area around the mercury and contacts is usually filled with a gas that surpresses the spark when the contacts make. Mercury relays are usually reliable and last for years in the proper environment. Heat is not good for them as the relay can explode and then you would have liquid mercury and gas from the explosion which is toxic. Does not happen often but can happen. Those type of relays are no longer allowed to be used without a special permit by the manufacturer. Each cylinder is a contact so when the coil is energized voltage can flow to the resistive element in your case. Any local electrician should be able to troubleshoot your circuit with or without a schematic. You will need a voltage meter.
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Got tons of volt (and even amp) meters. I don't need a schematic for that aspect... fairly straightforward.
BUT I'd like a schematic for the control panel. As well as an instruction manual. I don't know much about it other than turning the temp up and down... I can assume what the infinite logo is for but not much else on that display.
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So far I've ghetto rigged it as, A. I bought the wrong nuts for the bolts that I had (genius, I know) and B. I couldn't find high temp ring terminals yet.
I will remedy this soon though.
So I decided to drill out the rivets on the old panel and it was just a busted screw connecting the wire to the panel conductors (rusted and fell apart). So in ohming it out and making sure there were no other problems I ended up breaking the conductor that goes down inside the panel where it makes the 90 degree turn.
Assuming I can get to that part are there any suggestions on how to repair that? Obviously solder won't hold up to that temp. Some sort of clamp?
I still have to pull the other panel out and see if it's a similar problem and this time not be a jackass and break the conductor.
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So far I've ghetto rigged it as, A. I bought the wrong nuts for the bolts that I had (genius, I know) and B. I couldn't find high temp ring terminals yet.
If you have no local outlets, they should be available from Grainger, or here they are at McMasterCarr. http://www.mcmaster.com/#high-temperature-terminals/=e28s0l (http://www.mcmaster.com/#high-temperature-terminals/=e28s0l)
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Thanks... I might pop into Grainger today.
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GRRRRR!!!
So last night while I was printing a few shirts apparently my first panel went out (the last original one and the one with the temp probe in it). So now I have no clue if those shirts got fully cured.
I run them back through and slow the dryer WAY down and open the side to see when they start smoking... well they smoked alright... Scorched the F out of that first little shirt... cranked the rest way up then ran them back through again and THINK I got them cured.
So... now how does that temp probe go? Should I try to put it back in the INSIDE of the replacement panel or should/could I place it somewhere else in the dryer and let it measure "tunnel temp"?
I guess I should probably just pull it and see if I can fix it like the other one. Still unsure of how to "weld" that part of the element back together on the one I broke at the bend/joint (haven't REALLY looked at it).
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Pics would help. Post up some pics of the broken stuff.
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Pics would help. Post up some pics of the broken stuff.
Soon as I get home I will take some.
I must have put a decimal point in the wrong place
or something. crap. I always do that. I always mess up some mundane
detail.
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Long over due pics.
1st pic is the temp probe of the first panel and the hole that it went in. It had a glass tube inside it (part of it is sitting on the side.) The other 3rd panel that is also dead has the same hole. I could easily pull either one and see about repairing them at this point.
2nd print is the element ends. First problem was easy screw on the end had rusted and broken off. Then I pulled a little too hard on the element ends and broke off the piece that went down into the panel.
The final pic is a close up of where the element I guess was "welded" to the rest of the element in the panel.
Any clue as the best way to get to and marry the two parts back together?
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Also I have forced air in the dryer. Should I be using that even though I'm using plastisol ink?
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Bump
I just pulled apart the other two bad panels. Both broken in the same fashion.
I probably can pass a bolt through the element on one for sure and use a high temp ring terminal. But what can I do if that doesn't hold. I there is better metal further up but I'm not sure about drilling another hole. It will just weaken it. Anyway to fuse to it or clamp to it?
And what about my temp probe? Where should I put it... back inside the element once I fix it? Or should I put it somewhere in the cabinet under the element?
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It will probably never be as good a connection as the original spot weld, but perhaps you can make a clamp out of stainless fender washers and a small machine screw and nut.
Thing is, if the connection is at all dirty or tarnished or corroded, it exacerbates the problem because of the increased resistance and resulting heat, and it will fail again. So clean, clean, clean!
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That is my concern with the main connections and where they failed. They were just bolts and ring terminals.... and now they are very crusty.
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Ok... got some parts to attempt to repair the panels in my dryer.
Back to the pressing question. Do I put the temp probe back in the panel itself or do I rig it up outside the panel in the tunnel?
Under the panel? How far away blah blah blah?
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Any probe location and you'll have to learn what settings work for total cure anyways. Many
manufacturers go with panel temp, and I'd assume there's a reason for it.
You should use forced air for plastisol. I really think it helps with an even cure and no scorching.
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Sounds like a plan! Thanks for the answers!
I also bought a cheap oven gauge to stick up in there that I can check with a flash light or run through it at times... 4 bucks fun to play with.
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Got all three panels in there!
36 amps of heat now!!