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PID on Silvia


soundklinik
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Very interesting.. is it the Auber kit by any chance?

glevum

looking forward to seeing your end result. After having a Silvia for 4 years i just don't know why i never did mine!

Yes, I am pretty excited too...

 

It looks just like the Auber kit, with N2006P instead of Auber, but 5x less expensive. I chose a 12 VDC unit, (over 220 VAC, see the AC/DC transformer).

I put it all together after some research and I hope that it works well, I did an accuracy test of sensor....wired to PID to monitor temp and it is spot on, stopped on 100*C when water reached boiling point.

 

I am putting mine into a plastic box (for better heat protection and cost of box).

Anyway, I will post progress as I go on...

Cheers

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Work finished...fine tuning now...

While I was at it, I decided to insulate the boiler with pipe insulation material, dia. 60mm=2". Material thickness about 6mm. The final result is cleaner, with lots of metal tape sealing it all together and clear from electric connections.

I put soundproofing around the pump compartment. Great improvement.

Then I glued in place SSR and 220AC/12VDC transformer and hooked up all the connections to PID. Not many, 2 x SSR, 2 x 12VDC, 2 x Sensor.

The sensor is K-type -50 to +300C, hooked up under aluminium brackets holding down the two sensors. Between them.

 

That's all, there is a good amount of setup to do, so I think I will have to experiment with that...

Bye for now.:D

insulating boiler.jpg

PID action.jpg

PID c-Up.jpg

SSR and Transformar.jpg

boiler ins. detail.jpg

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  • 4 weeks later...

After some time of using/experimenting with PID'd Silvia, I settled down on SV=99C,... AH-1(on)= 99,.... and AL-1(off)=102C.

The terms A-HI/A-LOW alarm have nothing to do with Audio/Visual alarms in MY settings. The terms are used for setting in general, because the PID can also activate alarms if wired to a buzzer.

Cycle rate set to 25sec...to avoid the constant on/off flashing and wearing out contacts in PID...

The water temp measured in grouphead is about ~90C

Edited by soundklinik
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Not knowing anything about these things. If you had a pid on a classic would it transfer over to a sylvia or would you need additional or different bits?

L A L A T C...........29 and counting

 

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It should transfer as it is but you will most likely need longer wires as the Rancilio's case is bigger. Also depending on what thermocouple you've used, you might need to change that as well.

 

@soundklinik - what are you using the alarms for? I saw that you have two SSRs so I assume one is for the steam?

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Cycle rate set to 25sec...to avoid the constant on/off flashing and wearing out contacts...
You don't need to worry about contacts wearing out since SSRs don't have any. They'll happily work with

 

Where did you find the boiler insulation, btw? Looks good.

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You don't need to worry about contacts wearing out since SSRs don't have any. They'll happily work with

 

Where did you find the boiler insulation, btw? Looks good.

 

Yes you do, (not with SSR) but with PID itself, the constant cycling of 0.2 sec is too short and too slow recuperation time. It is much quicker with 25sec. time then a lot of short pulses. (After reaching SV, pulses are in 0.2ms)

 

I prefer Fig.7, Low alarm, my SV(set value) temp. is set to 102C.

AH1=101C This is where SSR kicks in once temp goes under or=101C

AL1=105C This is the Max temp allowed to reach.

 

The difference between the Fig.6 and Fig.7 is that theoretically, they work in opposite. Fig.#6 setup would bring SV to 102 and drop, while Fig.#7 keeps 102C as an absolute minimum. At least this is how I understand it and it seems to work that way

 

The insulation is from a DIY, best quality rubber insulation for pipes they had. 60mm inner diam. and 6mm thick 1m long. It feels like diver's suit and is incredibly efficient. My temp dropped from very warm cups to barely warm on top of Silvia.

Since it wants to curl up, I had to use a lot of Alu tape to hold it together...

 

 

dfk41

Not knowing anything about these things. If you had a pid on a classic would it transfer over to a sylvia or would you need additional or different bits?

 

You probably won't need much electronic wise. Probably some electric wire crimp connectors. Is the PID 220VAC or 12VDC? Does it have a wire sensor, which type? Sensor is mounted under the screw of alu holders between the 2 sensors (water/steam) on top of Silvia's boiler. If you need one, I have a spare, I will gladly send it to you...( Same one as in pictures above. Wire, K-type.)

It is best to have everything (AC-wise) connected to Silvia's ON/Off rocker switch. If you need any help, let me know.

PID manual.jpg

Edited by soundklinik
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A note about using an SSR to power steam on the alarm, the SSR should be AC-AC, not DC.

 

If you use DC and your PID outputs AC on the alarm circuit (the espresso machine will output AC from its switches and power in all probability and the PID won't modulate this in anyway) and try to power an SSR, the SSR will probably explode and take your PID alarm circuit with it.

Even in the case that there is any DC, the AC SSR should run anyway.

 

In terms of wiring though, silvia and the classic are more or less the same. Even the thread sizes for the tstat.

The only real difference between the machines is, as noted, silvia is bigger.

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A note about using an SSR to power steam on the alarm, the SSR should be AC-AC, not DC.

 

If you use DC and your PID outputs AC on the alarm circuit (the espresso machine will output AC from its switches and power in all probability and the PID won't modulate this in anyway) and try to power an SSR, the SSR will probably explode and take your PID alarm circuit with it.

Even in the case that there is any DC, the AC SSR should run anyway.

 

Why do you drag in here scenarios that I don't have and am not talking about...Did you even take a look at the components I used? I use One SSR only...

Relax, nothing is going to explode..lol

 

The PID itself is DC powered, with 12VDC that come from the transformer.

Second input into PID is the thermal probe that has +/- and must be respected.

 

PID output is 12VDC and goes to the SSR which relays AC to heater. The relay lets pass AC current to the heater and is activated by DC signal from PID.

Check out the input and output of the SSR in the picture. It is written on the top and bottom.

Input +/- 3-32VDC

Output 24-320VAC

SSR-detail.jpg

Edited by soundklinik
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Are you somehow using the relay output to trigger the SSR then? If you're using the voltage pulse output, it should work better at short cycle times.

 

No, you're mixing Relay with SSR. They are the same thing. SSR=Solid State Relay.

 

The way it works is; PID samples the temp via thermal probe 4 times per second. If PID notices a temp drop, it sends a signal to SSR, which closes the circuit (220VAC) and heat water in Silvia, in "pre-set" bursts. Once it reaches the temp, it cuts out and monitors. (Small temp difference=small bursts)

 

The short pulsating is used to keep steady temperature. The shorter the pulse=more accuracy. But I don't see any advantage in dropping temp in Silvias boiler by 10+C and bringing it up by short bursts.

 

The PID system bypasses the 110C thermostat switch on Silvia. Wires are removed from the thermostat and connected to the two SSR wires. I used double size, 1.5 sq. mm diameter, (instead of 0.75sq. mm) not to create resistance.

 

I should add, I am not trying to argue or convince anybody about anything, just sharing my results with PID users and people that think about doing it but aren't sure if they should...DO IT, it's worth it (on some machines) and really easy.

cheers

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No, you're mixing Relay with SSR . . .
I've used PID controllers a fair few times and am familiar with their wiring and general operation. Your posts don't seem to be self-consistent though. First you said you selected a 25 s cycle time to avoid wear to contacts. I therefore assumed you were using the contacts of the relay output to perhaps feed the SSR trigger inputs with 12 V. You now appear to be saying back to me what I've already told you that a short pulse width gives better control?

 

Also you seem to be suggesting that the alarm settings affect the control output. As far as I can see, these just open or close a separate set of contacts at the J1 (?) terminals. I'm not sure you fully understand what you're talking about.

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Can you please explain how you're using the alarms to set the low and high limits?

 

 

The alarm has nothing to do with the main SSR output which powers the tsat, once you activate the alarm, the pid will stop outputting to the SSR and just simply allow current to pass though the alarm circuit.

 

What you can do is wire the alarm circuit into a switch and, using diodes, back into the SSR on the pid output, then upon flicking the switch (provided you have some way of powering the SSR, as there is no current from the pid), the alarm circuit is complete, which activates the alarm function.

 

Usually this is used for steam with the steam switch.

 

I suppose though, you could use it to limit brew fall off, by wiring the brew switch into the alarm, then setting high and low to something like 107 - 108, it would ensure the boiler stays at that temp.

Basically, you would be using PID to maintain starting temp and use the alarm during the brew cycle as an electronic tstat.

 

I suppose its the pid equivalent of using the steam switch to keep the heater on.

 

 

I don't really know what the OP intends to do though, but to the best of my knowledge the alarm and pid function are a kind of boolean, you can have alarm or pid, but not both.

 

 

I suppose this is a pretty good diagram, albeit for steam.

 

 

In the case, you would just take the brew switch, not the steam switch and then set the high and low to whatever you want your brew temps to be at during the pour.

You can do it with two SSR too, but in that case it would be best to use it for steam.

PID.jpg

Edited by Kyle548
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