Jimbo's Electric Conversion

[HDNB]

http://www.brewhaus.com/1500W-Hotplate-P1029.aspx" onclick="window.open(this.href);return false;" rel="nofollow

holds the big milk can, a 54x2 with a 20x2" shotgun and 46L of wort. (i'd bet close to 60Kg's total ) Takes 3h45m to reach a boil, and the rest of the day to finish a run that big...but it don't cycle on High... and it still works.

that "rest of the day" thing is what motivated me to make the change to a 5500w internal.

[raketemensch]

Huh, that's a hell of a plate, and you've got a flat bottom, which I didn't realize. Don't take that personally....

[raketemensch]

So, new chinese triac/scr arrived today, so I wired up the two ins, two outs and the ground, plugged it in, and POP.

I've posted all of my wiring and a schematic to an electrical forum, and noone over there can see anything that I've wired incorrectly either. I'm out $60 on triacs and no closer to controlling the keg yet...

Oy.

[sambedded]

If you want proven quality prebuilt controller I can recommend this one - http://www.ebay.com/itm/-/191726022410" onclick="window.open(this.href);return false;" rel="nofollow

But first you need to check if you don't have a short circuit at your heater or heater wiring.

[raketemensch]

If you want proven quality prebuilt controller I can recommend this one - http://www.ebay.com/itm/-/191726022410" onclick="window.open(this.href);return false;" rel="nofollow

But first you need to check if you don't have a short circuit at your heater or heater wiring.

I just noticed that this latest SCR has a switch on it, where there was a heatsink on the previous one. Anyone else have one, and know what it's for? These come with zero documentation....

[sambedded]

I just noticed that this latest SCR has a switch on it, where there was a heatsink on the previous one. Anyone else have one, and know what it's for? These come with zero documentation....

Could you public a picture?

[HDNB]

If you want proven quality prebuilt controller I can recommend this one - http://www.ebay.com/itm/-/191726022410" onclick="window.open(this.href);return false;" rel="nofollow

But first you need to check if you don't have a short circuit at your heater or heater wiring.

that is a smokin' deal.

[HDNB]

So, new chinese triac/scr arrived today, so I wired up the two ins, two outs and the ground, plugged it in, and POP.

I've posted all of my wiring and a schematic to an electrical forum, and noone over there can see anything that I've wired incorrectly either. I'm out $60 on triacs and no closer to controlling the keg yet...

Oy.

But first you need to check if you don't have a short circuit at your heater or heater wiring.

I don't want to say that i told you to do this 10 posts ago....but i told you to do this...lest you suffer the same result.

Double Oy.

[raketemensch]

I'll take another look through to make sure that nothing is crossed, that's the only thing that makes sense at this point. I did check before, a couple of times, but something is obviously wrong, and I need to find out what. I'm also going to remove the element from the equation and do some extra testing at that end.

In the meantime, I've taken apart both of the units to see what's going on in them. The switch in the newer one is an on/off switch, although it's a tiny little thing that I'd be nervous reaching for. Here's a shot of it:

As you can see, that model only has Chinese writing on it. Here's the older model, just for comparison:

You'll notice that where the switch is on the newer model, the older one had something set up with a small heat sink. I have to wonder what that was, and why it's no longer necessary. Digging through both models, that's the only real difference I can see.

In this next shot you can see where it arced. On the right side is the bottom of the unit -- it looks to my uneducated eye as if the middle two wires are simply looped together and not run through any circuits within the SCR, am I maybe right about that?

Another thought that I had -- this is one of those bent ULWD elements, and when I took it out of the packaging it had been compressed so that the back-bend was touching. I pulled it apart so that this wasn't the case, but I wonder if maybe it got pushed back together while I was installing it in the keg. I'm not sure if that would make a difference or not.

Another odd thing is that it worked full-bore over the weekend, but couldn't be limited. If I had a short, that wouldn't work, right?

And finally -- I'm attaching the ground wire to the screw to the left of the inputs, which is just touching the case. It's the screw in the bottom left-hand corner of the first 2 pictures. That should be safe as far as I can tell.

In dissecting these I'm realizing that I've got fans, heat sinks and potentiometers in perfect order, maybe I can just order up an SCR and wire it together with the bits I have. I'm reticent to order another one of these right now.

[Hound Dog]

People seem to be using these without many issues but I went tried and proven myself with an SSR and potentiometer. Hasn't been a problem.

[HDNB]

Another odd thing is that it worked full-bore over the weekend, but couldn't be limited. If I had a short, that wouldn't work, right?

you would think so, but that looks like a short on the output to me. get an ohm meter (multimeter), 20-30 bucks and they are handy for all kinds of stuff!
pretty sure a 5500w wavy element should be around 11-12 ohms.

a smaller number (on ohm meter) than that can indicate a failed element; it may heat up if hardwired, but suck down too much current for the SSR to withstand. (think of the ssr as a fuse...the weakest link.)
with the scr failed, the 10awg wire you are using can take the current of a failing element, the next "weak" spot in the circuit in that circumstance is the element itself which would get hot...until it failed like the scr ( fuse) before it.

the element touching itself would not necessarily cause a failure, but if it was bent on insertion perhaps, a small crack from mechanical manipulation would cause failure.

disco the red/black from the output side of the scr (that goes to element), you should get the reading of 11-12 ohms between red/black(don't make your fingers parts of the circuit- test the wires "in the air" without touching anything else or if you have to press the probes down on something use a non-conductive surface, dry wood for example>) then test from the red to ground and the black to ground. these should show "open" or infinite ohms. no change on the meter from just holding the probes in the air.

this will prove the element and the wiring. any other result is indicative of a problem.

[raketemensch]

Thanks HDNB, I do have a multimeter here, I just need to find it....

[raketemensch]

[editing out a bunch of rambling crap)

I just went back and looked at Jimbo's original schematic, and noticed that he has no grounds going to the SCRs at all.

With no SCR, I get:

110v from each pole to ground
220v from pole to pole
~70ohm from pole to ground
pole to pole it continues going negative until kicking back to 0

With the SCR, I get:

110v from each pole to ground
220v from pole to pole
~70ohm from 1 pole to ground
0ohm from other pole to ground

Turning the potentiometer has no effect. I think I’ve basically just proven that my second SCR is also now blown.

Since I had time (running 10 gallons at 1375 watts takes a while...) I put my first SCR back together and tested it as well. All tests on it look identical to those first results with no SCR connected.

[HDNB]

With no SCR, I get:

110v from each pole to ground
220v from pole to pole
~70ohm from pole to ground
pole to pole it continues going negative until kicking back to 0

are you saying this is what you get when you test the wires going to the element with out the scr?

that would mean the element is shorted (0 Ohms) and there is a path to ground, albeit with some resistance (70 ohm) both bad things.

element pole to pole s/b 11-12 ohms. Either pole to earth ground should be "open". ( no deflection whatsoever on the meter.) you should have no voltage connected during this test. (disco the wires at the scr output, going to the element and test)

both of those conditions you describe would fry the scr.

[raketemensch]

With no SCR, I get:

110v from each pole to ground
220v from pole to pole
~70ohm from pole to ground
pole to pole it continues going negative until kicking back to 0

are you saying this is what you get when you test the wires going to the element with out the scr?

that would mean the element is shorted (0 Ohms) and there is a path to ground, albeit with some resistance (70 ohm) both bad things.

element pole to pole s/b 11-12 ohms. Either pole to earth ground should be "open". ( no deflection whatsoever on the meter.) you should have no voltage connected during this test. (disco the wires at the scr output, going to the element and test)

both of those conditions you describe would fry the scr.

That's with no SCR or element connected. That's the wires coming straight from the outlet.

[HDNB]

you be testing the wrong end. we already know the house hase voltage. and apparenty about 70 ohms to ground through your transformer!!!

don't mess with the live end of this, it will kill you.

*un plug it!!*
then:

check the element, disconnected from the scr, as described...it will test both the wire and the element.

[raketemensch]

The element is in the middle of a run at 120, so I can't disconnect it right now. Pole to pole, it's showing me an average of -60ohms. Not sure what's up with all the negatives.

[Monkeyman88]

Your probes are around the wrong way.

[Jimbo]

The element is in the middle of a run at 120, so I can't disconnect it right now. Pole to pole, it's showing me an average of -60ohms. Not sure what's up with all the negatives.

Cant be 60 ohms. At 120V that would be 240 watts.

[HDNB]

you are using the meter wrong no such thing as a negative ohm. you cannot hook it up backards. zero ohms is a dead short. just like people and plants...once they dead they don't get deader.

ohm meter also don't work on active circuits. well...they do but they measure the whole circuit. which can change resistance/impedence depending on what you are doing with the current...but we are straying off troubleshooting as to why you have smoked 2 ssr's back to back.

[Monkeyman88]

Still find it weird that there is two hot wires going into the scr. I thought that you needed one hot in and one neutral out.

[HDNB]

Still find it weird that there is two hot wires going into the scr. I thought that you needed one hot in and one neutral out.

no.

no,no, no.

let's not confuse this any more than it needs to be. scr's don't magically change electricity states from hot to neutral.

ok, maybe raketemensch's did...but that is the whole problem. we want this thing to control a heating element.... not go off in a brilliant flash of light and bad smelling smoke....

[Monkeyman88]

I'm just finding it hard to see how 110v into each leg of the element works, I thought it had to go in one side and out the other, like a lightbulb.

[HDNB]

exactly like a light bulb.

but 240vac is hot from P1 connected through to hot from P2.

120Vac is from one phase, or the other.... to neutral.

ssrs switch voltage, to a load... they are not a "load".... substitute the word element or lightbulb for "load"

neutral is not connected to an ssr, or a 240 device. only to the low side of a 120v load.

if you introduce neutral to a 240V device, or a "hot" switch of any descripition= bright lights..and smoke...

[Monkeyman88]

SSR or scr? I thought he had an scr

[HDNB]

now yer just being silly.

[Monkeyman88]

Well no. Because they are wired differently. Aren't they? SSR has one power in and one power out while an scr appears to have two power in and two power out.

[HDNB]

that ^^^ was a typo.

I'm gonna bow out here, i was attempting to offer some troubleshooting tips to avoid smoking more stuff, and keep a brother from getting a bad shock....but the additional red herrings are getting difficult to follow.

as i understand this circuit the drawing aforementioned is *correct download/file.php?id=24430&mode=view" onclick="window.open(this.href);return false;" rel="nofollow

*with the exception of the black line from the wall wart/fan to the volt meters, i'm not sure why that line is drawn, pretty sure it just a drawing error.

I will defer to the electrical engineers here to help out of they are so inclined. Edwin, are you reading?

[Monkeyman88]

Maybe some pics will help me explain. From what I understand, current should flow like this.

[Monkeyman88]

But it sounds to me like he has this.