Basic SSR based power controller.

[scythe]

So as the title suggest I'm wanting to make a fairly basic power controller using an SSR.
From my reading in this section and a little bit of background knowledge i've come up with an idea for a basic power controller.

Essentially it will be; power into the SSR, controlled by a potentiometer, and out to the element.
I'm wanting to future proof it so I'm going to build it to be able to power 2x10A elements, I'm not really ever going to have access to a 15A power point for distilling purposes, maybe i might eventually get one put in if I get a lathe, mill or really get into TIG'ing stuff at home but all of that is off in the never never at the moment

So my idea for now is:
2x SSR-25VA 2W units with heat sinks of some description (1 to start with),
2x 500K ohm 2w pots
2x 240V fans eventually (1 to start with),
2x power meters so I can check on the real time power draw without having to use my fluke meter/transducer.
and enough switches, 2.5mm wiring and cable glands to go around.

Still not sure on what sort of plugs i will use, might go with 15A plugs between controller and elements and then 10A plugs wired with heavy cable for between controller and power point.
I will probably run a dedicated power cable from the fuse box to my stilling area once set up.

So far i have;
2 potential boxes to use for my controller (powder coated steel), both rescued from my works scrap bin as they didn't suit what they wanted to do with them (should have gotten more as there was at least 15 of them in there at the time),
4m of 2.5mm power lead,
6 or so M16 cable glands,
I'm starting to look at getting the SSRs fairly soon so they are here before Christmas.

Is the agreed safe method still applicable for wiring SSRs?
The example given is for a PSR.


All that sound good?
At the moment i don't see a need to get a 40A SSR, unless you can convince me.

[rumdidlydum]

Yes but for piece of mind run an earth to your pot.
It also depends on what kind of power meter you run ie digital or analog.
I thought psr and ssr were the same :think: but i have been known to be wrong :laughing-rolling:
But as we all say get it tested :D
Look forward to seeing how you go :handgestures-thumbupleft:

[scythe]

Yeah I will earth the body of the pot as well.
Lucky for me the boily mate who is going to TIG weld my boiler up (when i finish all the fittings for it) is also qualified electrically.

Power meter i was thinking about the digital transducer type that can be found on ebay for about $15.

[punchy21]

So as the title suggest I'm wanting to make a fairly basic power controller using an SSR.
From my reading in this section and a little bit of background knowledge i've come up with an idea for a basic power controller.

Essentially it will be; power into the SSR, controlled by a potentiometer, and out to the element.
I'm wanting to future proof it so I'm going to build it to be able to power 2x10A elements, I'm not really ever going to have access to a 15A power point for distilling purposes, maybe i might eventually get one put in if I get a lathe, mill or really get into TIG'ing stuff at home but all of that is off in the never never at the moment
You will need to ensure that each element is on separate circuits.

So my idea for now is:
2x SSR-25VA 2W units with heat sinks of some description (1 to start with),
2x 500K ohm 2w pots
2x 240V fans eventually (1 to start with),
2x power meters so I can check on the real time power draw without having to use my fluke meter/transducer.
and enough switches, 2.5mm wiring and cable glands to go around.

Still not sure on what sort of plugs i will use, might go with 15A plugs between controller and elements and then 10A plugs wired with heavy cable for between controller and power point.
I will probably run a dedicated power cable from the fuse box to my stilling area once set up.
15A outlets are excellent peace of mind.

So far i have;
2 potential boxes to use for my controller (powder coated steel), both rescued from my works scrap bin as they didn't suit what they wanted to do with them (should have gotten more as there was at least 15 of them in there at the time),
4m of 2.5mm power lead,
6 or so M16 cable glands,
I'm starting to look at getting the SSRs fairly soon so they are here before Christmas.

Is the agreed safe method still applicable for wiring SSRs?
Yep
The example given is for a PSR.
same same

All that sound good?
Yep :handgestures-thumbupleft:
At the moment i don't see a need to get a 40A SSR, unless you can convince me.
No need...

[scythe]

Actually now that i think of it there may be a 15A outlet in the back shed, old matey who owned this house before we bought it was a bit of a dabbler and there is a 32A fuse in the fuse box marked for the back shed.
And another fuse box in the shed.
There is also an old hand held welding mask in there, I've just never looked closely at the actual GPOs in there.
That would be handy if there was one.
At least for now.

And yeah punchy, separate circuits for sure.

[maddogpearse]

I'm going to build it to be able to power 2x10A elements.

unless you're going to run 3 separate elements, i don't see any benefit of having a controller to power both elements? You can get any variation of power output from controlling one and just switch the other on/off. Or am i missing something?

[tipsy]

I'm going to build it to be able to power 2x10A elements.

unless you're going to run 3 separate elements, i don't see any benefit of having a controller to power both elements? You can get any variation of power output from controlling one and just switch the other on/off. Or am i missing something?

That's how I roll :D

[Psykamaholik]

Still not sure on what sort of plugs i will use, might go with 15A plugs between controller and elements and then 10A plugs wired with heavy cable for between controller and power point.

Sorry but it's not legal or safe to do it that way round, 10A on each element and 15A to the wall is ok though; or stick with either 10A or 15A plugs all round.

What size heating elements are you going to use? 2400W?

[scythe]

I will be rolling with 10A clamp in elements.
If its actually illegal then bugger it 10A plugs it is.

Altho i dont see why it could be illegal as it will only ever be connected to a 10A GPO, i could use 500V 20A plugs if i wanted between controller and elements.


My reasoning behind having both controllable is so that i can dial back both elements to the power of 1 to lessen the load on the circuit.
No need to drive in traffic with the engine bouncing off the limiter.
Also gives 2 points for bubbles to originate from.

[brewman]

It's not a problem when you use your 10A elements with 15A plugs on them.

It can be a problem if you or someone else plugs a 15A device into your controller like a 3600W element. The 10A GPO will supply 15A but it's not rated to do that safely. The end result could be an overheat and fire at the GPO or somewhere inside the wall of your house/shed.

As long as you understand that, it's a whole bunch of whatever. Can't see the point in talking legalities in this hobby.

[scythe]

Fair point.
10A plugs it is.

[Psykamaholik]

Can't see the point in talking legalities in this hobby.

:laughing-rolling: Fair comment!

It can be a problem if you or someone else plugs a 15A device into your controller like a 3600W element.

That was more the point I was (poorly) trying to make. :handgestures-thumbupleft:

[Nino]

I have had a 20amp power point installed in my shed and will be running both my 2400 watt elements through the controller. When I was looking to see if I had 2 separate circuits in the shed I found that all my outlets were on the the same circuit. But I did have a 15amp outlet so I was going to use the 10 and the 15amp outlets. The sparky suggested that I run a 20amp outlet and run both elements through the controller. Which left my 10amp plugs free to run my water pump and anything else that I needed to run at the same time.

[scythe]

Sounds like you will trip the breaker if you only have 1 20A circuit and then you are trying to run 2x 10A elements and sundry lights, pumps, radios, etc.

Or do you have 2 circuits?

[Nino]

Sounds like you will trip the breaker if you only have 1 20A circuit and then you are trying to run 2x 10A elements and sundry lights, pumps, radios, etc.

Or do you have 2 circuits?

Sorry I didn't explain it properly it is 2 separate circuits a 20amp circuit and a 10amp circuit

[scythe]

1 element on the 10A.
1 element and the rest of it on the 20A would be my plan.
Less chance of cooking the 20A, even tho it would handle it because of safety factors and such.

[Nino]

1 element on the 10A.
1 element and the rest of it on the 20A would be my plan.
Less chance of cooking the 20A, even tho it would handle it because of safety factors and such.

That will work too. I only run both elements on full power to warm up the boiler then I turn down the voltage to where it will do either a strip or a spirit run. It has worked out so far, but having said that if it becomes a problem them I will use the controller only on one element and run the second one through my 15amp plug. So, I do have options if needed. I trust the sparky that set it up as he was the one that rewired my garage about 18 months ago and he is familiar with the what the wiring can take. I have a separate circuit breaker board in the garage. I am glad now that I spent the money earlier to rewire the garage :).