Replacing a panel in my conveyor

[Gilligan]

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):


Can't see from the pic but coming out of that ceramic donut is a hard wire that forms a loop.

[MikeVastex]

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!

[Gilligan]

Thanks Mike.

So basically something like this:


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

[MikeVastex]

Thanks Mike.

So basically something like this:


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.

[Gilligan]

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?

[MikeVastex]

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.

[Gilligan]

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.

[MikeVastex]

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!

[Gilligan]

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.

[Gilligan]

Took a pic tonight.

[californiadreamin]

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

[Gilligan]

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)

[244]

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.

[Gilligan]

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.

[Gilligan]

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.