Aussiedistiller, Home Distilling, Moonshine, Home Brew

This just for general theory knowledge...make sure you seek professional help!

Power = Voltage^2 / Resistance
(P = V^2/R)

So 240^2/500k = 0.1152W

If you were using a 500k pot, it would need to be rated well above 0.1152 Watts to be adequately rated for the application.

If you were using a 500k pot, it would need to be rated well above 0.1152 Watts to be adequately rated for the application.

0.1152W will only be the Watts applied across the pot while it is in full position of 500K and not taking into the input impedance of the PSR-25. I use the PSR-25 at work and the data sheets states 250K at 1W. I wouldn't go below 1W.

Thanks Kyranr and Brendon. Would you say that these two items look like a good match together?

Solid State Relay - SSR-25VA, 24-380V(AC), to suit 470-560k ohm
http://www.uxcell.com/24380v-25a-soid-s ... 45476.html

Potentiometer - 470K Ohm, 2W
http://www.uxcell.com/replacement-6mm-s ... 78828.html

As noted earlier, it will be controlling a single 2200w element.

Thanks again.

I haven't used that one personally but the datasheet does list the the pot at a 2W rating. Heatsink looks good and I would dare say it would already come with heatsink compound between the SSR and the heatsink as it is comes as a unit. This gets left out a lot because people don't know to add it but it helps to transfer the heat to the heatsink. I'd say it looks the goods mate. Just remember to earth the earth tag on the side of the pot or earth the metal box if you are using one and it will earth through the nut of the pot.

Thanks Kyranr, I'll go ahead and order them. The old man is wiring it up for me, so he can do what needs to be done to make it compliant. He is getting old and is not so great using the ol' inter-ma-thingy, hence why I am ordering the parts!

Probably a dumb question but for the on off switch do I just get a 240v 10a switch?

I went with ebay items
"Fan http://www.ebay.com.au/itm/281717245422?ru=http%3A%2F%2Fwww.ebay.com.au%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D281717245422%26_rdc%3D1

"ssrhttp://www.ebay.com.au/itm/331399214792?ru=http%3A%2F%2Fwww.ebay.com.au%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D331399214792%26_rdc%3D1 "

"pot http://www.ebay.com.au/itm/391149007808?ru=http%3A%2F%2Fwww.ebay.com.au%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D391149007808%26_rdc%3D1"

"voltmeter http://www.ebay.com.au/itm/331212795451?ru=http%3A%2F%2Fwww.ebay.com.au%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D331212795451%26_rdc%3D1"

If you plan on using a 3600W element or upgrading to one in the future then go a 15A switch. If you are sure you'll only be running a 2400W element then that will be fine :handgestures-thumbupleft:

Thanks cheers

Bit confused about yummyrums post about the metal enclosure.

I understand that the insulation in the pot can fail making the centre twisting "handle" of the pot live, but why would a metal enclosure earth the centre of the pot were earthIng through the circuit would not.

If the insulation in the pot failed wouldnt it be live regardless of enclosure? Or am I on the wrong track?

The enclosure which is earthed would earth out the pot so if anything happens it would blow the cicuit breaker so nothing is live.
If you are unsure don't go near it. :-B :handgestures-thumbupleft:

So do the mounting points on the pot earth the centre twist knob to the enclosure which is in turn earthed to the trip switch which will trip out when voltage is applied,
where the earth tab on the pot[which is connected into the internal wiring] does not?

Yes
Not many have an earth pin. i solderd the wire to the body of the pot

Cool thanks now I understand cheers :handgestures-thumbupleft:

punchy21 wrote:Through a collaboration between yummyrum and myself, here is the latest revision for the PSR-25...

So if you wanted to run this via extension lead, How would you go about earthing it obviously a sparky would know but id rather minimize the time he spent checking it over

jacobraven wrote:So if you wanted to run this via extension lead, How would you go about earthing it obviously a sparky would know but id rather minimize the time he spent checking it over

Do you mean earthing your boiler or the controller?

Knocked one of these up last night. Works a treat. Just waiting for my volt gauge, but testing with a power meter (Gives volts/watts/amps etc) shows it is nicely controllable with a 260K pot.
Well done Punchy.

Hi all, I've got a couple of questions about using the PSR-25..

I'm looking at the data sheets and its got an F175 supply filter in the circuit, for what i assume is protection for the rest of the circuit? Or is that performed by the SCR fuse in this diagram? (I've attached the RS components data sheet)

http://docs-asia.electrocomponents.com/ ... 02e5aa.pdf

This part is pretty pricey, but doesn't appear in any of the circuits on here. I was wondering a) what it does and b) whether its needed.

The other question was what is the relevance of the resistance rating of the potentiometer? I've seen both 250K and 500K in the versions on here, and as long as the power rating is sufficient (saw 1-2W) what resistance rating is needed when running 240Vac, 10A (2400W) through the PSR-25?

Thanks in advance for any responses :)

T

I think for the pot you need what your psr is rated for as I didn't know when I ordered and the psr had written on it was 250 an I had the 500 pot,and this didn't give me the full votltage range.so bought the 250 and all was good :handgestures-thumbupleft:

:text-+1: match your pot to the requirements of the SSR.
Im not sure about the fuse you are talking about, but in punchy's diagram there isint one :think:

I was going off the diagrams in the SSR, which i think are circuits designed for processes where you need to protect things elsewhere in the circuit. I'm happy to give this a bash without the signal controller thing the data sheet refers to.

One other question, the diagrams have fans in them. I was going to add a heat sink, which obviously need a bit of air flow. Has anyone has any luck doing it without fans and just a heat sink? I was looking a power supplys/transformers, and they seem dear for a 5w unit (like $80), when a 100w unit is like $20. I'm looking at an analog voltmeter (to cut down on the fluctuations), so if I can get away without the fans, I'm sure I can save a fair bit on that power supply. Otherwise I'll need to work something out.Maybe an old lead acid backup battery to run the fans.

Cheers again!

T