TexAir 410 EEE Tune Up

[ZooCity]

So, with much beer drinking, scrubbing and adjusting, we have our TexAir fully installed and operational.  This is a 48" wide 5-10-5 model, all electric.  They have 2 IR panels on the intake, a chamber of partially recirculated forced air that is heated by a set of induction heaters then 1 more IR panel on the outtake.  1 of our 2 intake IR panels are not operational, which is of no concern as we are manual printers and should not need it.  What we do need is the forced air section to be hot enough to fully cure discharge inks.

The forced air section is essentially a big ass squirrel cage fan that draws air from the chamber into a run of venting, passes it over the induction heaters before guiding it to air knifes which blow it back down into the garments.  The induction heaters are just after the squirrel cage blower/air intake.  Just before the heaters is a thermocouple.  There is a second thermocouple up top in the air chamber that feeds into the air knives.  Readout on the panel for the forced air is in alignment with what the atkins probe is telling me- about 180 deg F appears to be the upper limit.  The dial is set all the way up which, according to the dial ought to be 300 deg F. 

I checked the dryer over pretty well today, crawled in there to clean and inspect and pulled out the induction heaters which looked just perfect- very clean with tight connections all around.  IR panels are doing their thing well enough it seems, panels are around 800 degrees maybe, according to the raygun which has a hard time with temping panels.  The panels are likely a little old and tired but again, I didn't get the dryer for the IR panels I got it because it was close to me, cheap as dirt and has tons of forced air flow.  I couldn't care less about running all three of those IRs, I want the hot air. 

At a belt speed of 4 on the digital readout (about 3 minutes in the chamber) a shirt is temping out at 420 deg, with everything cranked (keep in mind I have one dead panel up front).  However, I'm perplexed about the forced air chamber temp, it's holding at around 180 deg with a single, dry shirt and the probe.  I heard Alan mention the donut probe tends to read low compared to IR but even if it is, 160 deg doesn't seem like a good temp to keep the shirt at for the bulk of it's journey in the dryer.  Maybe it's really at 200 deg but that's still too damn low.  I'm seeing mfg recommendations for 2-3 min. held at 320-360 deg.  A minute and a half at those temps and the rest of the trip at 180ish doesn't seem like a good plan but maybe it will work ok? 

In any case, I had intended on using the forced air section alone with just a touch of help from the panels which coincidentally is exactly what the texair manual I got form GPI recommends to do.  No way that's going to work at the temp I am seeing.  My first thought was the thermocouple(s) need replacing but if the panel readout matches the donut probe....?  Again, there is a thermocouple in the top of the chamber and one at the bottom of the ducting, just before the air hits the induction heaters.  I presume the first tells the panel how much juice to give the induction heaters based on what the second is reading out and what the dial is calling for.  This would implicate the first thermo in the venting as the second appears to be doing it's job.  It could be the induction heaters have gone into semi-retirement as well I suppose. 

Any thoughts?

[ZooCity]

Also pertinent: 

the atikins probe does indeed display much lower temps than the raytek gun but again, inline with the panel readout.

I looked at the panel and my electrician installed a 70a breaker (these are 3ph) for the TexAir.  It calls for 100a on the panel I believe.  The assumption was that it wouldn't need that amount with the third panel out of operation and there's apparently a big price jump when you hit a 100a 3ph breaker.  Now wondering if this is effecting it's ability to temp up in the hot air chamber.

[alan802]

What temp did the ink get up to with the donut?

It took a while but I finally got the donut probe to read the correct numbers and to give you an idea of the difference in gun and donut, the gun was reading up to 375 when the donut was at 320.  When I'd hit the shirt with the gun and the temps were around 320-330 at exit, the shirts were undercured.  I am not one of those guys who things the guns are all that bad, but I trust the donut way more than I trust the gun readings.  I think if you can get the temp up to 310-320 with the donut, you are good, but if the gun is reading 320-330, I'd not trust that the garments are cured.

[ebscreen]

Derp.  Thought gas for some reason.  Does the temp control have a readout or just a dial?

[ZooCity]

for the forced air section it had a dial to adjust temp and then a readout

[ScreenFoo]

How hard is it to get to the control circuitry, and contactors/relays--and if it's easy, do you have any idea what the resistance across each panel and each inductor is? 

Just because the connections look good at the heater doesn't mean there aren't multiple crappy splice jobs on the way back to the control box, if you haven't checked the whole length of wire.

[ZooCity]

it's pretty sim to get to everything. almost all of it is up front. in fact this whole machine is really simple in overall design.  I have a full grip on it already, slow as I am, all but the stuff that falls in the category of electronics that is.

 fire zone wire to the induct heaters looks perfect across the run but I'll check again.  I actually crawled in there and followed the lines last night, even pulled the heaters out to inspect, pics attached.

 I'll see what I can see in the panel today. I wonder if the hot air temp dial or something on it's circuit is wonky? 

today I'm going start by trying to modify how much make up air the chamber is getting. if that air can recirc longer it will get warmer.

fwiw, I have the bonnet up high as it will go. I'm sure that makes a slight difference but not a hundred degree difference.

running theories are- something in the panel like a fuse, not enough juice to the machine, that bottom thermocouple that reads the air temp before it hits the heaters.

[ebscreen]

Thats pretty damn clean.

Not enough juice would mean a tripped breaker and nothing else. Some IR panels are wired in such a way that if one leg of the circuit is missing it will still heat up, just half as much. Just a thought. Have you temp gunned the panels at full bore?

The second thermocouple likely controls a damper of some sort? Might have an issue there, stuck open or something.

 Lastly, I am not familiar with the way the electric forced air works, but it might be that you do need all three panels or else you're just sucking cold air. Maybe try switching panels around.


Sent from my porch using Tapatalk

[ScreenFoo]

Nice job cleaning, for sure.

I'd also seriously doubt it's juice--either you have enough to fire the heaters, or the breaker will trip--if the right connections are made.  Do you have continuity indicator lamps for each heater, and are they lit or cycling?

You may be able to trace that wiring from the inductors to the contactor, and fire it manually with a properly rated switch at the control box to test them out.

The other thing I'd wonder is tangent to the cold panel--if it's rated at 100A for 3-ph, and you dropped to 70 because of one panel--does that mean the inductors, belt motor, and all other circuitry run on three phases @10A?  Cause that ain't gonna put out a whole lotta heat compared to a panel that draws upwards of 30A 3-ph...

[ZooCity]

I picked this up from a guy running circuit boards, membrane panels and the like through it so it didn't take much to get it to this point.  The whole thing is in really excellent condition, just old.  That's why I really don't think it's effed up wire runs, everything looks tip top and is really easy to track around. 

One of the last pics I posted shows those heaters, there's 12 of 'em and 6 indicator lights for them on the panel.  The lights are dim, maybe just dirty and I thought they were all on.  Well I turned off the lights and only two are on- I think it's just fuses.  derr... should've check that out properly from the get go.  It's possible that the elements are shot as well but I doubt that, they looked pristine. The indicator lights are functioning properly for the 3 IR panels, showing the 2nd is out so I have good cause to figure they're giving me an accurate readout for the air heaters.  From the pics, do you guys think you can find fuses like this locally? 

So the way this guy works with the hot forced air is it has a big ass squirrel cage that sucks the chamber air in through some furnace filters, pushes it over these electric induction heaters in the previous pics and blows it back up around and down onto the belt.  If you slice the dryer open width wise, looking at the slice from the outtake, the path is sorta like a letter G with the flat part of the G being the filtered intake and the top of the hook being the air knives.  On the same spindle as the big squirrel cage, a smaller one pushes air back out at a lesser rate and up through our roof vented run of 12".  It's really dirt simple.  I attached some pics from the manual, left my robot phone at the house or I would take actual pics.

{In fact, I want to look into retrofitting it with gas possibly.  All it would take to do this would be to replace the electric heaters that heat the recirculating air with a gas unit right?  It looks as basic as a home heating system in there.  Thinking I could have an hvac guy do the math and tell me what needs to go in there and we could maybe even use a used gas furnace of the proper BTUs and put it's exchanger in where these electric heaters are now if there's room and then vent the heater properly.  Maybe that's crazy talk though.}

But anywho... on that letter G, you have a air reader sort of device at the bottom of the G, right before the air hits the heaters.  It runs with a fat copper tube along the bundle with the firezone wire that powers the hot air heaters and terminates into the air pressure switch (see pic) in the panel.  So yeah, good call eb, but I think that guy is just there for the safety buzzer that goes off when there's not enough air flow?  If it's a damper control I don't know to where. 

One weird thing I noticed it that there are vents above each of the IR sections and, when you run a shirt through smoke comes out of 'em.  I thought these were the intakes for the forced air and I'm surprised that the forced air system isn't sucking those fumes down into itself.  It's possible that they zoned it really well by design.  If so, that means I need to put our vent system in sooner than later.  We are currently turning on the big vent fan in the washout room which used to be paint booth and letting it draw air through the shop from the front window/doors for general ventilation. 

Our logic with lowering the breaker on this was, I thought, sound.  We would crank the forced air section all the way up and add back just enough panel heat to get to temp for manual production, up to two presses at a time.  So the 30a drop wasn't banking just on that one panel being out but on using less all around.  From what I was hearing from those using EGE models, with gas firing the hot air section, it sounded like the bulk of the power draw was coming from the IR panels.  I felt like 70 would be plenty.  Like you all said, if it wanted more than 70a, the breaker would trip.  I thought we would do as above and mark the max temp we can juice the IR panels up to without throwing the breaker or, more likely, the breaker wouldn't throw since one of the panels isn't drawing.  If we needed more production capacity that would mean we need an all gas dryer, these wouldn't be worth running for the power bill.

[ScreenFoo]

I have no idea where to get "Specifty" type fuses... Must be proprietary. 
They look kinda like HAC-R or ECN-R, but shorter...  maybe.    Can't really see too well from the PDF pics--got a good pic of the inside of the panel?

[ZooCity]

well it held enough heat to cure my first run of discharge.  CCI d base with about 0.6% activator, 2 hits through a 225/40 coated 2/1 thin with Aquasol on anvil 980s in lake blue. I'm cramping your style Tony.

[Printficient]

Chris,
Please call Winston Strickland.  904-343-0848.