My electric control rig and a question regarding my element

[Waylan_Britefire]

Hi all,
This is the controller build I have been working on while awaiting the arrival of my still. Runs off the 30 amp dryer outlet in my garage. 10 awg for the whole build with an inline volt and amp meter. Twist lock receptical to plug in the 4500 watt heating element. Bought a Chinese "scr" controller off Amazon for $20 rated at 10 kW( it's in quotations as I believe it to actually be a triac controller as an scr will only put out dc voltage and are more expensive than triacs). I'm a maintenance electrician by trade but I have a question for those that have previously built. How have you protected the connection point for your wires going to your heating element, both from pull and potentially getting wet, while also sealing the heating element? My element screws into a 2" triclamp ferrule (see photo below). The element threads are straight pipe threads and the ferrule threads are taperd pipe threads. I though about mounting a junction box that is held in place by the threaded connection between the element and the ferrule but I fear that will allow a leak. Thanks for taking a look.

[Tony1964]

Hi there

I fitted an IP68 junction box to the rear of the element, obviously remember to earth the element, as yours also has a tri-clamp fitting this will have a PTFE seal for the clamp, so, and I see your qualified electrician, but, remember to earth bond the element and the still as the PTFE will provide a isolator.

Mine was originally a 4KW element, but, was 2 X 2KW elements in parallel, so, I split the elements, as in disconnected the parallel connections and control both elements desperately, you can see the orange cable coming out of the junction box, on the other side is a white version, and for convenience of moving around, they terminate with IEC connections, in the UK we aree on 240V so, I run both elements from different 13A sockets, technically they run from a double socket outlet which are rated at 10A per socket for compliance, so, 20A max from the double socket.

They run max around 7.5Amps in practical terms, as the Elements are really only 1.7Kw each, what a con I know, but, that's marketing for you.

Obviously goes without saying some form of RCD is required.

Hope that is of some help.

Cheers

Tony

[Waylan_Britefire]

That's what I was thinking, some form of weatherproof junction box with a Teflon gasket. Just wanted to confirm from someone with a build already under their belt before I bought anything more. The breaker that protects the circuit is a GFCI breaker, but thanks for looking out for safety.

[Tony1964]

Hello again

Just read your post again, the SCR you will have, will not put out DC, SCR controllers have diodes that are both forward biased and a second diode that is reverse biased, one will conduct in the positive AC direction, the other in the negative direction, the turn on of these diodes is controlled by the Gate pin, the Gate firing is what controls how much power is delivered, it always delivers 240v or 120v but the Gate turns of the power, so, in say the USA your on 60hz, if I controlled the firing of the SCR to 30 times per second this would deliver 50% of the power as the power, it is always 240v or so, 120V in most cases for the USA guys, adjust the phase firing to 15 times per second and your at 25%, does that make sense?
Your always switching AC, assuming you have the controller I think you have

Cheers

Tony

[StillerBoy]

How have you protected the connection point for your wires going to your heating element, both from pull and potentially getting wet, while also sealing the heating element?

My is done using a 1" weld spud with a 1-1/4" rubber pipe joiner with an electrical plug.. as per the picture..

You just gave me an idea on how to remodel my setup by using a tri clamp.. where did you get the ferrule for the element and what size is the tri clamp for..

Mars

[Waylan_Britefire]

Hello again

Just read your post again, the SCR you will have, will not put out DC, SCR controllers have diodes that are both forward biased and a second diode that is reverse biased, one will conduct in the positive AC direction, the other in the negative direction, the turn on of these diodes is controlled by the Gate pin, the Gate firing is what controls how much power is delivered, it always delivers 240v or 120v but the Gate turns of the power, so, in say the USA your on 60hz, if I controlled the firing of the SCR to 30 times per second this would deliver 50% of the power as the power, it is always 240v or so, 120V in most cases for the USA guys, adjust the phase firing to 15 times per second and your at 25%, does that make sense?
Your always switching AC, assuming you have the controller I think you have

Cheers

Tony

Tony-, I am aware of how paired scrs can be used to create a pulsating ac sine wave form, same way that frequency drives work on 3 phase motors. I just assumed that for the price that it was a triac controller labeled scr because it's from China. Now I'm going to have to open up the case and look at it to see what the guys are truely made of.

How have you protected the connection point for your wires going to your heating element, both from pull and potentially getting wet, while also sealing the heating element?

My is done using a 1" weld spud with a 1-1/4" rubber pipe joiner with an electrical plug.. as per the picture..

You just gave me an idea on how to remodel my setup by using a tri clamp.. where did you get the ferrule for the element and what size is the tri clamp for..

Mars

Mars, the triclamp I have is a 2" with a 1" NPT fitting. I got it from Barley Hops and Brewing in Texas, ordered online. But they can also be purchased on Amazon with a quick search. From Amazon they come in many different size combinations for the triclamp and NPT sizes.

Thanks to both of you

Waylan