Will this POT suffice for a controller build?

[Demy]

Sorry Demy, the first time I read your reply it didn't sink in.
I don't necessarily think the voltage reading is that important for the box's intended use. In my feeble mind, I think the bigger concern is how much current you're allowing to flow to the element. I've been reading some of the other threads as well related to the used of a course, and fine pot. So as I lay out the lid of the box, I want to me mindful of the possibility of adding a 2nd pot, or just adding a graphite resister. I don't think either addition is going to be something I will end up wishing I had done from the very beginning, but rather a future improvement in performance.

No problem, you don't have to apologize for anything. I recommended that connection because those displays show volts and also calculate watts in pase to inputs, so if you give wrong inputs you will get incorrect data. I figured if you bought that display you want that data.

[Deplorable]

It's always good the have data available.
It's going to be easy enough to move the CT. I'll likely try it on both sides of the VR. If it shuts off at very low current flow, I can always move it upstream of the SSVR.

[Deplorable]

I think this covers it. Please verify my connections to the SSVR, as it's always good to have someone check your work.

[shadylane]

Looks like it will work.

[Deplorable]

Looks like it will work.

So the numbers on the SSVR connectors are meaningless? Or I just happened to get it right?

[shadylane]

Must have been luck

[Deplorable]

Must have been luck

Good enough. I'll ground the pot and the heat sink, the check continuity on everything, and put some water in the boiler and check it all out before I use it to run my SSS.

[StillerBoy]

Please verify my connections to the SSVR, as it's always good to have someone check your work.

From what I see in the picture, your power breaker only break power going to the element..

If that so, I wouldn't recommend setting it up that way.. the minute you plug your controller in the power outlet, your whole unit is live, not a good idea..

I build my with the power going the the breaker first, then on to rest of items..

Mars

[StillerBoy]

My error on the breaker position.. sorry

It just that it's wired in reverse from what I do and the diagram on the thread I posted for you..

Mars

[Deplorable]

My error on the breaker position.. sorry

It just that it's wired in reverse from what I do and the diagram on the thread I posted for you..

Mars

My 50a in the panel is already a gfci, so I didn't see the need for a 2nd breaker, just a double pole switch.

[Deplorable]

Neither of the potentiometers are any good. Hooked up the first one, and it wouldn't work at all. The 2nd one was full of dead spots and wouldn't give me more than 2750w to my 5500w element.

[shadylane]

I'll ground the pot and the heat sink, the check continuity on everything, and put some water in the boiler and check it all out before I use it to run my SSS.

Where on the pot did you hook the ground to?

[Deplorable]

I'll ground the pot and the heat sink, the check continuity on everything, and put some water in the boiler and check it all out before I use it to run my SSS.

Where on the pot did you hook the ground to?

Per their instructions

[shadylane]

I'm 99% that's wrong. Do you have an ohm meter?

[Deplorable]

I'm 99% that's wrong. Do you have an ohm meter?

Yes.

[shadylane]

First disconnect the ground from the pot and see if the controller works.
Be careful the metal shaft on the pot may be HOT.
Only touch the plastic knob

[shadylane]

I'm 99% that's wrong. Do you have an ohm meter?

Yes.

Here's how the pot is wired inside.
There should be 500,000 ohms between pins 1 and 3
The value between 1 and 2 or 2 and 3 should vary between zero and 500k as the knob is turned.

[Deplorable]

I'm 99% that's wrong. Do you have an ohm meter?

Yes.

Checking resistance between 2 and 3 while turning the knob slowly, indicates variations in the pot from 0.36m at the bottom of the adjustment, to ~235k in the middle, then dropping ot 0 before getting to the end of travel on one pot.

The other behaves similar on the fluke 23 meter, but the display indicated open spots on areas of travel where resistance drops to 0 then back up.

[Deplorable]

Both pots, are here when tested between 1 and 3

[Deplorable]

First disconnect the ground from the pot and see if the controller works.
Be careful the metal shaft on the pot may be HOT.
Only touch the plastic knob

I did this last night, it made no difference. One pot worked intermittently, the other not at all

[shadylane]

I'd take the tin can off the back of the pot and check the wiper arm.
And use a pencil eraser to clean any oil or crud off the carbon.

[Demy]

The connection should be done between 2 and 3. If connecting 1 and 2 the knob will lead to the contrary. The earth I don't think centers nothing with pin 1.

[Deplorable]

I'd take the tin can off the back of the pot and check the wiper arm.
And use a pencil eraser to clean any oil or crud off the carbon.

I've set up a return of the items. But at a cost of $5 each, what have I got to loose besides $10 and my time.

[Deplorable]

The connection should be done between 2 and 3. If connecting 1 and 2 the knob will lead to the contrary. The earth I don't think centers nothing with pin 1.

Measuring between 2 and 3 as shown in one of the pictures posted shows that neither pot has a reliable gradient in resistance, and neither will come close to providing 500k.

[shadylane]

You can test the SSVR by hooking a jumper wire between pins 3 and 4 on it.
The output should be 100% when the terminals are connected and zero without the jumper.

[Demy]

Forgive my stupid design, perhaps it will help.

potenziometro.png (9.57 KiB) Viewed 1267 times

[Deplorable]

The SSVR worked last night when fiddling with the first pot. I could get 2750w for a time, then it was like the contacts opened on the pot, and output dropped to 0w.
The water was heating in the boiler.

[Demy]

The SSVR worked last night when fiddling with the first pot. I could get 2750w for a time, then it was like the contacts opened on the pot, and output dropped to 0w.
The water was heating in the boiler.

Have you checked the wiring above? I don't want to insist forgive me, only it seems strange for me that 2 out of 2 of those potentiometers are dead.

[StillerBoy]

Deplorable.. I'm somewhat sadden that you have experience failure with your controller built..

But on the other hand, you didn't followed what I advise to do. there would not have been no failure..

You seem to enjoy disregarding some good advise, and take joy in making life hard for your..

I did point out that it was wired back, but you did not get that.. that's unfortunate..

Enjoy the journey of hardship..

Mars..

[Yummyrum]

Per their instructions

Unfortunately their instructions were not intended for use with a SSVR and were just generic connection advise where the Pot is actually used as a Potentiometer with all three connections used .
When used with a SSRV , it is using only two of the three connections as a variable resistor .

It is unfortunate for you that they labeled one of those terminals as Ground . While this is probably a fair description in the case that it was used in a Potentiometer application , I sadly think that by you having connected it to ground , you may have burnt out both pots and possably destroyed the SSRV .

When one grounds a Pot , it is done by soldering a wire to the metal casing of the Pot or to a large washer attached to the mounting nut .

Some Pots are sold with a special 4th terminal which is attached to the case for connection of a ground wire .

You can test the SSVR simply as suggested by Shady . IE , link a piece of wire across the Pot terminals and it should run Full power . Disconnect the wire link ( nothing connected at all) and there will be zero power .

If this test works , then your Pots are burnt out .

Do be aware when measuring Pots that They have a Nominal 500kohm value due to manufacturing variations and can measure anywhere from 450k to 600k .