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Lawrence Ruskin
05-30-2012, 12:41 PM
I have a Stadelmini and I went down to charge and temp had droped to 1350 and stayed there
The elements are glowing but not as much as usual.

OK now this is my electrician Saying 240 volts at breakers 114 amps on each line to the furnace.
So what's happening?

Lawrence Ruskin
05-30-2012, 12:43 PM
oh yeah all the wires that I looked at seem ok

Lawrence Ruskin
05-30-2012, 01:22 PM
we checked all the fuses, looked at the elements and they look like they are the same temperature. Looked foe burned wires and arcing and nothing

Steve Stadelman
05-30-2012, 02:00 PM
You can try calling me again

Lawrence Ruskin
05-30-2012, 02:12 PM
Is that the number that ends in 1061?

Lawrence Ruskin
05-30-2012, 02:13 PM
Is that the number that ends in 1061?

or 9922?

Lawrence Ruskin
05-30-2012, 02:25 PM
Hi Steve,

My electrician is doing a small job around the village and should be up here within an hour so I will phone you then.

Hope you're doing well,

...L

Steve Stadelman
05-30-2012, 02:30 PM
9922...........

Lawrence Ruskin
05-31-2012, 04:00 PM
So my electrician seem to think my machine is OK, he talked to Steve, and Steve thinks it's in the controller, that stinky little watlow

So I'm getting another electrician this weekend.

I can't seem to use the watlow tech repair line that is watlow2 'cause I'm up in Canada so does anyone have another number for watlow tech repair.

We have one in Vancouver but the guy doesn't speak English very well, I am getting very discouraged, I am sure it makes sense to someone to have a tech support guy with 11 words of English but it's very hard on the customers that don't speak Cantonese.

So what's going to happen if the power is somehow boosted, I have been reading the archives and it sounds like it's hard on the transformer.

Steve Stadelman
05-31-2012, 05:10 PM
Call 507-454-5300. Ask for randy.

Steve Stadelman
05-31-2012, 05:10 PM
Your transformer will be fine.

Pete VanderLaan
05-31-2012, 05:12 PM
Having talked to Steve it sounds like the 4-20 milliamp signal is not fully outputting. Things do break sometimes. Google Watlow and get the right number. Watlow has the best customer service of anyone out there. You may need another 4-20 milliamp controller. Waiting until the weekend will get you weekend hours. Do it now.

I don't do Watlow. I use another source for that stuff.

Lawrence Ruskin
05-31-2012, 06:55 PM
Thanks guys,I just got two more numbers
1 8004 watlow and 1866 202 0705.
I will talk to that electrition again about that 4-20 milliamp controler

Lawrence Ruskin
05-31-2012, 07:40 PM
So I guess that my electrician told Steve that the 4-20 milliamp controller was not fully outputing or that's his best guess?

Is there some way of testing it and if it's shot just replacing it should do the trick?

Steve Stadelman
05-31-2012, 08:02 PM
What the hell? I gave you a direct line AND the name of a SUBJECT MATTER EXPERT to contact! Do you have stannis chloride poisoning!? CALL Randy and TALK to him rather than blathering on about it on this board! Watlow has the best customer service there is!

Rollin Karg
06-01-2012, 05:21 AM
When you finally figure it out, then think about adding some spares to the mix.

Pete VanderLaan
06-01-2012, 06:09 AM
When you finally figure it out, then think about adding some spares to the mix.
****************
I agree. 5:01 friday afternoon is always a bad time to be making phone calls.

Lawrence Ruskin
06-01-2012, 09:58 AM
I'm doing the best I can, I live in a little village North of Vancouver. My usual electrician is in Mexico, and it took me a week to find another one, then he didn't show up then another week to get the guy Steve talked to.Nobody wants to come out here, It's an hour long drive if you live around the South end of Vancouver.

I tried the 4 watlow line first, then when that didn't work I tried the guys that sell Watlow locally and that didn't work but I got one that finally phoned me back and gave me the numbers I posted.

Pete VanderLaan
06-01-2012, 10:07 AM
I think it's really important when you are isolated by choice to learn to fix the machines you rely on. If I could do it, anyone can do it. I really believe that.

Steve Stadelman
06-01-2012, 10:12 AM
At this point you DON'T NEED an ELECTRICIAN!!!! SERIOUSLY!!!! Call 507-454-5300 and get through the menu to technical support.

Pete VanderLaan
06-01-2012, 11:52 AM
Before 5:01 PM since they aren't open on weekends at tech support

Lawrence Ruskin
06-01-2012, 12:46 PM
Randy is on vacation but I talked to another guy and we went through the program. The controller is putting out 100%
It's still not coming up to temp the way it would before whatever happened,happened.

So what is it?

Lawrence Duckworth
06-01-2012, 01:03 PM
Is the watlow seeing the correct TC type?

Lawrence Duckworth
06-01-2012, 01:04 PM
Is the watlow seeing the correct TC type? Did that get changed somehow through all the mashing by you or sparky?

Lawrence Ruskin
06-01-2012, 01:17 PM
the TC wasn't touched the day it went down.

The TC hasn't been played with.

When I did that rebuild because of the corrosian problem, then I did take it out and wired it back in but it worked well untill lately..

Steve Stadelman
06-01-2012, 01:37 PM
If the control is truly putting out 20 milliamperes, check the wire terminations at the control and the S.C.R. Perhaps there is a little corrosion. Also check the fuses in the power train, did the unit get installed with dual-element slo-blo fuses? Those can lose an element and still conduct enough electricity to run the equipment in a crippled way. Look at all connections with a ir thermometer. Wash, rinse, repeat.

Steve Stadelman
06-01-2012, 01:42 PM
Also, don't give up, Watlow is in the office for a while. Call back and talk to them again and explain your situation. You have an scr that seems to be getting a good signal but not putting out power. Don't just get an answer and hang up. This is detective work sometimes.

Lawrence Ruskin
06-01-2012, 02:16 PM
So I phoned back and told another guy what you told me and he asked me to take some measurements of the various things in there, something I'm not competent to do.

So I talked to my electrician and he said all he remembers about taking the measurements was the two wires going to the elements were 114 amps each.

He suggests I take out the program I use to bring the machine up slowly up to temp and just put one in that just is controlled with the setpoint.

Lawrence Ruskin
06-01-2012, 02:16 PM
So I phoned back and told another guy what you told me and he asked me to take some measurements of the various things in there, something I'm not competent to do.

So I talked to my electrician and he said all he remembers about taking the measurements was the two wires going to the elements were 114 amps each.

He suggests I take out the program I use to bring the machine up slowly up to temp and just put one in that just is controlled with the set-point.

Rollin Karg
06-01-2012, 02:42 PM
I think it's really important when you are isolated by choice to learn to fix the machines you rely on. If I could do it, anyone can do it. I really believe that.

Pete is correct, this part is very important. Start a log of the trouble shooting process and the info from the Tech people. This would include the time of the call and the number you dialed and the persons full name. Learn to take the electrical readings yourself and don't rely on your Mexico bound dude for info.

Living out at the edge of the world is cool, but self reliant capabilities are imperative. A written log is a wonderful thing when your tired and the pressure is on.

Lawrence Duckworth
06-01-2012, 04:23 PM
Even so, I would make sure the watlow control is seeing the correct TC. Toggle through the program and see if the TC setting matches the furnace TC.....it could be that simple!

Lawrence Ruskin
06-01-2012, 06:40 PM
But you see I'm looking for something that changed the day my furnace started to go down.Some part that screwed up

I didn't have a power outage, possibly a power surge,who knows My lovely GB3 would have told me if the power went out.

I'm going to try and get my guy that went to Mexico out here at the same time the watlow techs are in.

And I have built my own SiC furnaces since 84 but these Molly's are more complicated.

Pete VanderLaan
06-01-2012, 06:46 PM
Pay more attention to what Steve said about the slow blow fuses. That's a very likely source of your trouble. Sometimes they just blow. Get two, one as a spare . They're not as common to purchase as you would think and they are pricey. You just take the fuses out and check their continuity. Check the 4-20 milliamp output on the controller. They go from the controller to the SCR. Use a good multimeter.

Lawrence Ruskin
06-01-2012, 07:55 PM
The slow blow fuse is the big one?

I only saw one big one and the continuity was good

Steve Stadelman
06-01-2012, 07:57 PM
There will be two in the disconnect your electrician hung on the wall.not the semiconductor fuse in the control panel.

Cecil McKenzie
06-01-2012, 07:59 PM
I think Lawrence means, is the correct thermocouple type entered in the Watlow?

Steve Stadelman
06-01-2012, 08:29 PM
I would really like to see the thermocouple issue set aside for now. I think partially blown two-element fuses or bad signal conduction between control and scr are more probable at this juncture. Pending the arrival of the peripatetic electrician.

Lawrence Ruskin
06-01-2012, 08:31 PM
what disconnect my electrician hung on the wall?

the power goes from the house panel to the studio panel, then to the control box, then to the elements.

Steve Stadelman
06-01-2012, 09:03 PM
Hmmm, we always recommended hanging a fused disconnect.

Pete VanderLaan
06-02-2012, 07:18 AM
That was probably because it was code to put one within five feet of the appliance.

Lawrence Ruskin
06-02-2012, 10:30 AM
the studio panel is 5 feet away.

The guy that wired up my furnace is the guy that helped me last week.

The guy that's going to help me this week knows more about electronics.

and has a better tan.

Lawrence Duckworth
06-04-2012, 07:58 AM
I think Lawrence means, is the correct thermocouple type entered in the Watlow?

The way I understand it the control comes with a factory default
program, I don't remember if its an R, S, K.... but I do remember Randy saying it was important when he helped walk me through the setup.....just something steve might not have been aware of when he was tying to build these things.

Lawrence, let us know how it goes. Thanks.

Mark Wilson
06-04-2012, 09:05 AM
it is possible that there is some leakage current entering your TC line, which causes the controller to malfunction. inspect your TC.

Pete VanderLaan
06-04-2012, 10:02 AM
I genuinely believe the TC issue is a red Herring. If the controller is making a constant call for power then it isn't the TC. The question becomes the level of the call which could be anywhere between 4 and 20 milliamps. If it isn't 20 milliamps when it's off by 1000F then there is a problem with the controller. If you can't measure the output because you don't have the skills, there's a problem. Given that 240V is flowing through the SCR on the input and output sides, the controller is more likely.

Steve Stadelman
06-04-2012, 01:35 PM
The way I understand it the control comes with a factory default
program, I don't remember if its an R, S, K.... but I do remember Randy saying it was important when he helped walk me through the setup.....just something steve might not have been aware of when he was tying to build these things.

Lawrence, let us know how it goes. Thanks.

Given that I built several hundred of them, ................I am aware of factory presets. The problem is, and remains, that Lawrence cannot measure anything.:)

Pete VanderLaan
06-04-2012, 02:26 PM
Lithium, bring Lithium! We have a code !

Lawrence Ruskin
06-04-2012, 05:01 PM
My furnace creeps slowly up.My electrician comes tomorrow. I will ask him how to use my multi meter for measuring things I don't measure now.

I will take notes.

He is reading this thread by the way.

So be nice...

Pete VanderLaan
06-04-2012, 06:15 PM
I don't think anyone is being unkind. They are saying you need to take ownership of the technology that drives your system. That would include knowing your thermocouple type automatically and knowing how to take basic readings with a multimeter. The SCR is a device that chops up the sine wave into bite size manageable chunks. It gets its marching orders from the 4-20 milliamp signal from the controller which gets its marching orders from the type S or R thermocouple. The signal running from the controller to the SCR can vary from a low of 4 milliamps to a high of 20 milliamps. At the top, it is asking for all the power to flow. At the bottom it is asking for minimal power. Since your electrician has established that you have 240V in and 240V out of the SCR, the question then becomes how many amps are getting through based on the signal call.

So the first order of business is to measure that signal. If at that point you have a weak signal and you are below your set point by 800F, it would be a good plan to just change out the controller and see if that improved things. It will take more than a few days to have one in your hands so you might want to get the spare that Rollin referred to, ordered. It's just a fancy switch with some bells and whistles.

Rick Sherbert
06-04-2012, 06:22 PM
I'm away from the manual and my furnace at the moment, but I recall a easy way on the watlow to see what percentage of output the controller is asking for. If you are off 1000 deg and the watlow tells you the controller is asking for something less than 100%, then I would think you look at the controller. If it shows the controller IS asking for 100%, then I would look at the SCR and everything down line from that. I'm with Pete, the TC is a red herring.

Learn the ways of the multi-meter and the amp-clamp young padiwan... The (electromotive) force will be with you.

John Riepma
06-04-2012, 06:38 PM
Re-reading the first post in this thread, where Lawrence says that the electrician reads 240v and 114 amps on each line going to the furnace - that's an awful lot of current for something that is losing temperature. I can believe 114 amps going to the furnace from the transformer, but that would be at 60v or 36v. Rick's comment/suggestion is a good one in the absence of measuring capabilities. I'm not sure if Lawrence is using a Watlow controller, but if it's a 981 you can tell what the output is that's being called for by the controller by pressing the "display" button which will cycle you on the lower display through deviation from setpoint, farenheit/celsius, and % output being called for as well as returning to the setpoint display.

Pete VanderLaan
06-04-2012, 06:56 PM
I believe Lawrence has the 80 lb 10KW furnace. It can't be pulling 114 AMPS of 240V. It should be under a 60 or 75 AMP breaker ( I think). It should use a 6/12 300/450 element which pops at 2500Watts. It draws 15 volts ideally. It is possible it has the 300# package in it which draws more, but still not 114 AMPS. My 23KW system doesn't draw that much at 240V. That has to be a transformer draw of amps and it should be more.

I might be a tiny bit off on those specs of Steve's since I didn't build it.

Steve Stadelman
06-04-2012, 07:01 PM
Lawrence actually wrote that he has 240 AT THE BREAKER, and that tells us nothing except he has electricity. 114 amps was from the leads to the heaters and that is WAY LOW for a 6/12 heater. Those should be running about 180 amps when heating. Also, the amperage is NOT LINEAR. if you have a system that is running around 150 amps it is running at about half power.

Lawrence Duckworth
06-05-2012, 08:23 AM
So... Why not check the control setting? Just for kicks see if you have an R or S, tc, and make sure the control matches up, at least you'll know how to do it when you replace the control.

Still....what caused this thing to crash to 1300f and stay there?
Many of these furnaces blow fuses and the half ass answer is to use an oversized fuse  
 

Pete VanderLaan
06-05-2012, 08:44 AM
Knowing what your thermocouple type actually is is a very good thing and I think it's an excellent idea to find that out! It is just unlikely that the thermocouple type is the issue here.

The furnace could crash as it did if the milliamps being put out by the controller were on the lower end of the 4-20 milliamp range or even in the middle. As Steve pointed out, having the output to the elements fall by even 15 percent will cause a serious deterioration in performance in wattage output by the elements.

Lawrence Ruskin
06-05-2012, 09:37 AM
John, when those measurements were taken the furnace was coming slowly up.

Steve Stadelman
06-05-2012, 09:39 AM
The long and short of this is that Lawrence doesn't know how to do anything towards maintenance or real operation of his furnace.

Lawrence Ruskin
06-05-2012, 10:03 AM
um Steve, I've built one wire and two SiC furnaces the last one was quite a beautiful machine.It ran for 12 years.

Up till now I haven't had to probe about in a live electrical box featuring 240 volts. today I will learn what all those gadgets are and learn how to measure the current.

The bottom line is in the 20 years i've been building furnaces I haven't needed to know this stuff...

Pete VanderLaan
06-05-2012, 12:30 PM
The bottom line is in the 20 years i've been building furnaces I haven't needed to know this stuff...
****************
I am impressed that you could go that long without knowing your thermocouple type at the very least. You still need to take ownership of the technology and maintaining it. You can't solve all your problems in internet chat rooms. Successful SiC equipment use SCR's and compatible controllers.

Lawrence Ruskin
06-06-2012, 04:00 PM
I know what kind of TC I have: it's the kind that came with my Stadel-mini,
I have it written down on the pile of papers this little drama generated.

One of the reasons I'm not all familiar with all that stuff that came in those big metal boxes,is from 1983-4 when I built my first SiC until I took my second one apart a couple of years ago, with the exception of getting a piece replaced on my SCR, that box didn't so much as burp in all that time.

It's downstairs in storage and if I reuse it I sure it will start up and go for many years

I'm hot again, and hopefully my electrician will log on again and tell you all about it.

Thanks for all your help and concern guys.

Pete VanderLaan
06-06-2012, 07:37 PM
I deleted Steve's post at his request but we both think the same thing in actuality. I have been informed that the controller was in fact putting out 28 milliamps. Too high is just as bad as too low.

Lawrence Ruskin
06-06-2012, 07:57 PM
yeah, we think the controller just decided to go down and when it came back up, it came up very weakly.
Nobody pressed any buttons as I'm the only one that gets near it.
So it's a mystery,an expensive one.
Steve Synotte built a good controller box but he certainly screwed up when he recommended people use the closed cell bayonet style elements from kanthal instead of the I2R version. He cost me $10,000 when that was a lot of money, he was sued by many people for that one.
Stuff happens when you're building new equipment.
Don't take offense Steve, none was intended.

Dave Howard
06-06-2012, 08:50 PM
Ok, here we go. I arrived at Lawrences place and his oven set point was 1850 and his process variable was 1770 and not moving. Scr was outputing 193 volts and Z2 was lit meaning it was in current limit. The transformer ratio is 4.8:1 so 193 volt output means 40.21 volts @ 160 amps on heaters for total of 6.4KW. The transformer is 8KW so we increased the current limit on the scr controller to about 7.7KW and confirmed no other parts of the circuit where above ratings. The question is why did it work for so long, so well. I am sure nobody adjusted the limit on the scr.
It is true the temp controller was outputing 29mA at 100% demand. I used my process calibrator to set the scr so know it was done at 20mA. I would like to cycle the temp controller to measure its output in the future but all seems to be operating now.
T/c wires are rd/blk suggesting it is R or S.
There is no signs of corrosion or high resistive conections anywhere in the circuit. Happy melting Lawrence, give me a call if you have any questions or would like more details.

Pete VanderLaan
06-07-2012, 06:09 AM
Generally the current limiting has been set to about 85 percent of the capacity of the transformer in the systems I have seen. That translates into Amps when you adjust it and that would indicate that 7.7 KW is about as close to an 8KVA transformer as you would want to get.

Thank you Dave for the diagnosis. I hope you were able to show Lawrence around the control panel with a mulitmeter. Sometimes these things just wander off in to the forest and get lost. These systems do seem to show troubles when they are turned back on from a cold start. I just turn mine down to 20F and leave it on when I plan to shut down. I then throw the panel breaker to the SCR as well but leave the controller on.

I don't actually like the Watlow controls. I find they let the operator have more choices than they actually need and the flexibility can get you in real trouble. The Watlow EZ series is anything but easy. I am using an entirely different SCR which works very well. Charlie Correll has been putting Partlows in our furnaces which I also find to be opaque at times.

Whether offense was intended or not, it was effectively present and persistent. Unfortunate to lose resources anytime.

Lawrence Duckworth
06-08-2012, 09:12 AM
:) wouldnt it be nice to figure out why it did what it did so maybe something could be done to prevent that from happening again. :)

Tom Fuhrman
06-08-2012, 10:05 AM
I've been asking that about my wife for over 30 years aned still no answers!

Randy Kaltenbach
06-08-2012, 10:55 AM
Damn, coffee sprayed all over the keyboard again...