After a couple of false starts I eventually built one.
I read much about power controllers，probably too much, frightening me in the process and making me delay the construction. Now that I have made one, I do not know why I was so concerned - many thanks to all those who posted before me and made it possible.
I eventually chose to go the SSR / Potentiometer route.
With this Potentiometer I cannot turn the power all the way down to zero. I am now reliably informed by MuleKicker that I should have used the larger of the two values stated ie 560K
For cooling I mounted the SSR with heat transfer cement on one of these;
I added a couple of PC cooling fans and some meters put the bits in a box with a couple of outlets
and this is it - Click the picture for a closer look;
It took about five minutes before the novelty of watching the meters wore off. After that, it was a case of just winding the knob on the potentiometer to “about there”. Adding the bigger dial and longer pointer takes the guesswork out of what the setting was the last time and makes the process a lot more repeatable.
Last edited by YHB on Mon Mar 19, 2012 1:44 pm, edited 1 time in total.
Looks good, one thing I would add to those fans is filter on the to help prevent dust building up on your eletronics thus building up a static charge, Try google-ing "Fan Filer" or "Fan Filter 80mm" (assuming that is an 80mm fan) for some simple foam filters.
I thought that the inability to turn the power to zero was a function of the SSR. I now realise that it is a function of my lack of knowledge about things electrical.
I had assumed that the two values (470-560K) quoted for the Potentiometer were a "range" that would service the SSR, my assumption now appears wrong.
I will order a new 560K Potentiometer, thanks for your help it is much appreciated.
560K ohms is considered open circuit (0 current flowing) to this specific module. Some are 1M, and in between. Your pot, only opening up to 470K, doesnt give the module a complete open circuit (in its mind) so it does not turn off completely.
Very nice, I know MuleKicker had to clarify mine for me too. I ordered the 470 pot as well seeing this one started at 470. I have ordered the 2w 1M ohm pot, but haven't got a chance to run it right yet. How is that fan working for you? I'm having to leave my cover off for air. It gets hotter than I thought . I was going to incorporate 2 in mine with one forcing air in and one forcing air out. Would really like to hear how your fan is doing.
As it happened my Potentiometer was fine. When I first tried it out, the Boiler had a thermostat fitted. Removed the thermostat and the SSR covers the full range 0 - 240 volts, very smoothly.
No issues with the fan, I have planty of ventilation holes at the back of the box, you can feel quite a draft blowing through the box.
I copied his and built the same for my 5500 watt heater. Worked flawless....no transformer, everything is rated for 240V. Didn't even need a fan with mine...mounted it all in a control box and runs cool. It's running right now as a matter of fact. Only around $50 in parts.....other than the heater wiring
YHB, could you explain the function of the toggle switches, that red thing in the middle, and the 12 VDC (in or out)?
Thanks.
In Flanders fields the poppies blow * Between the crosses, row on row, * We are the Dead. Short days ago * We lived, felt dawn, saw sunset glow, * Loved and were loved, and now we lie * In Flanders fields. -- from a WWI poem
The red thing in the middle is an emergency stop. If I am called away from the still I press that and everything is switched off.
The three toggle switches are for the two cooling fans and the 12v DC outlet. They are not needed but I had them available and used them for their inbuilt lights to give an indication that things are working.
The 12Volt outlet was for an Air Cooled Parrot on a new all electric still was thinking of building (I still am). Should any one add this facility then YOU MUST USE A DIFFERENT PLUG TYPE to ensure that a 12 volt appliance cannot be plugged into a higher voltage outlet.
Pretty close to that. I didn't wire in a switch...just turn the rheostat to max and SSR is off....then just plug and unplug, I also put in an ammeter and voltmeter. I do like those, though the cheesy chinese ammeter failed after a couple runs. But I can be consistent on power to the heater just by knowing voltage as well.
I thought it was a great write up and has worked flawlessly for me. The parts were inexpensive enough....I ordered 2 of everything in case I have a failure down the road. Best of luck
I'm ordering my parts to build a controller similar to yours but i was wondering. Since the SSR is only on one of the power lines when you turn the power off does the element just half in volts or does it go completely off?
holiday wrote:Since the SSR is only on one of the power lines when
I am sorry but I do not understand the terminology "one of the power lines" - I have my controller wired for the UK system, 240v Live and Neutral system and yes it does switch off completely.
If I understand you correctly when you are refering to more than one power line and you are in fact refering to a three phase system. I am sorry but I cannot help you and more research is required or you should seek the help of an electrician.
Well I hope I'm correct when I explain this. I'd hate to make a fool of myself. But in the us there are 3 wires for a 220v plug. 1 wire grounds it and the other two carry a 110v a piece. So theoretically in my opinion. I'm not an electrical technician or anything but if you only limit one of the 120v I don't see it turning off completely.
holliday wrote:Well I hope I'm correct when I explain this. I'd hate to make a fool of myself. But in the us there are 3 wires for a 220v plug. 1 wire grounds it and the other two carry a 110v a piece. So theoretically in my opinion. I'm not an electrical technician or anything but if you only limit one of the 120v I don't see it turning off completely.
It will turn off heater completely. The only issue is safety since one live wire still be connected. So to stop a heating it's enough to break a circuit in one place, but to do any maintenance you need to disconnect both wires.
The element only has 2 wires to it. And for it to work both of those wires need to be connected. So the circuit is made. If either wire is disconnected. Then there is no longer a path for the electricity to follow.
Kinda like the cooling water flow to a condenser. With a valve on it. With the valve open water flows too, in, and out of the condenser. You shut the valve and you no longer have flow through the condenser. So its shut off
holliday wrote:Well I hope I'm correct when I explain this. I'd hate to make a fool of myself. But in the us there are 3 wires for a 220v plug. 1 wire grounds it and the other two carry a 110v a piece. So theoretically in my opinion. I'm not an electrical technician or anything but if you only limit one of the 120v I don't see it turning off completely.
It will turn off heater completely. The only issue is safety since one live wire still be connected. So to stop a heating it's enough to break a circuit in one place, but to do any maintenance you need to disconnect both wires.
Very well said...the heater element completes the circuit,,,
__________________________ BB 2" Boka, 2" Pot..interchangeable with a 2" condenser head and a 3" Condenser head.Electric Kegs w/dual controllers complete and in training...
. I was going to incorporate 2 in mine with one forcing air in and one forcing air out. Would really like to hear how your fan is doing.
