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Switch for PID

Posted: Sun Apr 21, 2019 5:38 pm
by Down_Home52
First let me say I am not an electrician. I am not trying to automate my still. I sit in front of my still and use the controller in manual as I watch the temp at the top of the column. I acquired a home made controller with a bunch of carboys and SS kegs. I was using it tonight and it quit working in the middle of the run. The SSR 25 relay went bad. The 120v side of the relay breaks the ground leg of the 120v going to a receptacle where the element plugs in. The low voltage side of the relay I measured at 9 volts out of the PID. Question is could I break the negative side of the wire from the PID with an on/off switch so I can power the PID up without powering the element? Working with DC power on my race boats we use relays for everything that operates in the rear of the boat so light wire can be ran from rear of boat to dash for both safety and weight purposes. Was just wondering if i could treat the low side of the SSR in the same way ? This is a 7.5 gallon set up and the 1500 watt element does a decent job. When I am running time to get up to temp is enjoyable.

Re: Switch for PID

Posted: Sun Apr 21, 2019 6:40 pm
by Yummyrum
Firstly . Any advise is use at your own risk .
I can only assume that you have a PID that is controlling a SSR 25 DA type SSR .

If this is the case then yes you could put a switch inline with either if the two control wires going to the SSR control side .

Some have even wired a switch so its always on , always off or controlled by PID .

But now the questions .
If your SSR has failed , how has it failed ?
Usually its permanently on ... IE ,it goes short curcuit and the element is just always on ....so if this happens , there is no point disconnecting the control to the SSR as its going to be always on regardless of whether try to remove the drive .

Wondering why you don’t just replace the SSR if its faulty ?

Also curious why you would want to keep the PID powered up but not controlling the element ? Is it just to use the thermometer reading ?



Also , PIDs are not needed for distilling . Unless you were using a PID in manual power mode .

Re: Switch for PID

Posted: Sun Apr 21, 2019 8:27 pm
by Kindafrench
I would suggest forgetting ssr and pid and buying a new SCR. Take one with double the power your heater draws. For example: 2 kw heating element = 4 kw controller. Cheap chinese ones on many online stores. Watch Big Clive on these. He‘s a good entertainer :D
https://youtu.be/_4PwYm_7HKg

I use mine with a cooling fan to extend it‘s lifespan.

An old PID controller is only used to show the temperature in my setup. I set it to 78.4 °C in cooling mode, so that the lights start to blink when it‘s time to think about collecting hearts in big jars :clap: . Just a fun thing and saved some bucks, because I had it lying in the drawer.

Re: Switch for PID

Posted: Mon Apr 22, 2019 3:28 am
by Down_Home52
Yummyrum the SSR is bad and I am replacing it. The current set up had a switched receptacle arrangement downstream from the SSR. I think a heavy duty 20 amp receptacle would be better. I still wanted the ability to switch off the element without powering down the PID. As stated I use the PID in manual mode only.

Re: Switch for PID

Posted: Mon Apr 22, 2019 3:31 am
by Down_Home52
KIndafrench I used what I had and it worked for several runs. I strip in a big pot over propane but use the electric for spirit runs. I can run it inside in the winter when it is cold outside. I will view the video to see what you are referring to. Thanks for the feedback. Always appreciated.

Watched the youtube video. Is the SCR all you need to control the element? Would you run the ground to the terminal he mentioned need a ring connector and piggyback another wire there going to ground on the receptacle? Did you mount yours in an enclosure with a small fan?

Re: Switch for PID

Posted: Mon Apr 22, 2019 10:24 am
by Kindafrench
There are 4 terminals on the SCR. It is super easy to connect.In priciple, you can connect the two wires, which were switched by the (PID)SSR, to terminal 1 and 4. That‘s it. As you can see in the video at 13:50, the terminals 2 and 3 act like a piece of wire, no real function in the circuit. The case has to be grounded, for safety!
Not all controllers are made the same way, so don‘t take for granted, that markings or connections are the same.

I put it all in a metal case (old computer powersupply). I put a small fan in the powersupply case, which blows some air through it.
Controller
Controller
I put an on/off switch on the back.

An extra main power switch is useful, but not a must. Just unplug the controller and you‘re safe.

To be able to help more, some photographs would be good.

Always unplug and check before start fiddling around with your controller or any wires, which could possibly contain high or any dangerous voltage / current.

Later, I will use a bigger case. That would give some space for funky extras.

Re: Switch for PID

Posted: Mon Apr 22, 2019 11:09 am
by Down_Home52
Found a neat SCR with built in fan on ebay. 4000 watt. 115/120 AC. If I use a plastic enclosure, which I have, should I run a neutral from the wall outlet to the neutral on the element which would terminate inside the plastic enclosure. I would also want an On/Off switch. Here is my current set up. I will build another one to use the SCR.

http://www.kegkits.com/Basic%20120V%20P ... roller.pdf" onclick="window.open(this.href);return false;" rel="nofollow

I am going to put a switch in the negative lead from PID to termianl 4 on SSR.

Re: Switch for PID

Posted: Mon Apr 22, 2019 9:58 pm
by Kindafrench
If the SCR has an inbuilt fan, it needs both lines, neutral and phase to be connected.

Could you provide a link to the controller on ebay, please.

But anyway, connect power in (neutral and phase) to the controller and the heating element, too. No extra wiring.
If you want a switch, use one with a matching switching capability of minimum 20 amps. Your heater draws 12.5 amps at 120 V. So the cable has to be 14 AWG equals 2.5 mm^2. What‘s the full lenght of your cable?
There is a voltage drop along the cable, which lowers the voltage to your heater and heats up the cable.
I read, that it is more standard to use 12 or 10 AWG cable at 120 V and 14 AWG would be borderline.
Could somebody comment that, please. I live in a 240V area, so that‘s a different game.

The plastic casing needs enough holes to vent. If it gets too hot in the case, you may start a fire and or need a new controller soon.

Re: Switch for PID

Posted: Tue Apr 23, 2019 4:56 am
by Down_Home52
SCR with fan on ebay.

https://www.ebay.com/itm/4000W-AC110V-1 ... SwHQdcbmt5" onclick="window.open(this.href);return false;" rel="nofollow

I don't see anywhere for the ground to attach to the SCR. That is why I asked about grounding the element. I am using a 6 foot long power cord to the element. 12 awg.

If I was using 220v I would get one of these

https://www.ebay.com/itm/4000W-SCR-Elec ... Sw0~lcqr4j" onclick="window.open(this.href);return false;" rel="nofollow

Re: Switch for PID

Posted: Tue Apr 23, 2019 8:25 am
by Kindafrench
Ground wire can go, where the red arrow points to:
Controller
Controller
Loosen the screw, twist the ground wire around it and tighten. May not be professional, so take care that it doesn't rip off. When you remove the potentiometer knob, there is a nut and thread. Could be a place where you can connect the groundwire, when you put it in your plastic case. Between the fan and the case. Many places available.

Grounding the element / boiler is a must.

12 AWG wire on 120 V looks good, imho.

There seems to be no fan in the 230 V version and your heating element is 120 V. That does not go together!

Re: Switch for PID

Posted: Tue Apr 23, 2019 2:44 pm
by Down_Home52
Thanks sir. SSR 25 relay came today so I can put my controller back together. I will try the SCR for another boiler I have under construction. I like the PID unit when I mash in using my boil pot. Working on a new mash tun. to use brew in bag. Large Rubbermaid HPDE garbage can on outside. Styrofoam blocks in the bottom with a smaller HPDE can set on those blocks so tops of both cans are even and centered. Expanding foam then pumped into the cavity between the two cans. Get the strike water a little hotter than needed, pour it in barrel to let the barrel heat up. When strike water is at correct temp for volume of grain lower it in and cover. After conversion I lift the bag out of the tun with a ratchet strap and let it drain while I stir the converted liquid with a paint paddle on a drill to cool. Works pretty good. Ferment right there in the barrel.

Re: Switch for PID

Posted: Tue Apr 23, 2019 2:55 pm
by Yummyrum
I hope your replacement SSR had the suffix “DA”
If you have received a “ VR” or “VA” type , do not connect it to your PID as it is the wrong type .

Re: Switch for PID

Posted: Tue Apr 23, 2019 4:09 pm
by Down_Home52
It is DA. Going to need it. Have a batch of agave mash working right now.

Re: Switch for PID

Posted: Wed Apr 24, 2019 3:50 pm
by Down_Home52
SSR and switch worked out real well.

Re: Switch for PID

Posted: Wed Apr 24, 2019 7:11 pm
by Yummyrum
Down_Home52 wrote:SSR and switch worked out real well.
:wave:

You can also use a three position switch
Position 1: off
Position 2: connected to PID
Position 3: connected to a 12v dc supply so its full on .

Re: Switch for PID

Posted: Thu Apr 25, 2019 11:33 am
by NineInchNails
Down_Home52 wrote:First let me say I am not an electrician. I am not trying to automate my still. I sit in front of my still and use the controller in manual as I watch the temp at the top of the column. I acquired a home made controller with a bunch of carboys and SS kegs. I was using it tonight and it quit working in the middle of the run. The SSR 25 relay went bad. The 120v side of the relay breaks the ground leg of the 120v going to a receptacle where the element plugs in. The low voltage side of the relay I measured at 9 volts out of the PID. Question is could I break the negative side of the wire from the PID with an on/off switch so I can power the PID up without powering the element? Working with DC power on my race boats we use relays for everything that operates in the rear of the boat so light wire can be ran from rear of boat to dash for both safety and weight purposes. Was just wondering if i could treat the low side of the SSR in the same way ? This is a 7.5 gallon set up and the 1500 watt element does a decent job. When I am running time to get up to temp is enjoyable.
You should have your black wire/the hot wire running to the one terminal of the SSR then on the other terminal of the SSR the hot wire should run to your heating element. In other words, the SSR should break the hot wire to your heating element.

You said "the relay breaks the ground leg". That does not sound right to me at all. The ground is just a ground and should never be 'broken'.

Re: Switch for PID

Posted: Thu Apr 25, 2019 8:54 pm
by Kindafrench
NineInchNails wrote:You said "the relay breaks the ground leg". That does not sound right to me at all. The ground is just a ground and should never be 'broken'.
You are right. The phase/power should be cut by the SSR. It is the safer version, but in function it‘s the same. Here in Europe, it is possible in many countries, to put the plug in the socket the way you want. This leads to changing neutral and phase in the connected device. Usually the device doesn‘t care about that, as long as it gets both, power and neutral.
Older devices may hum or have a simmering power indicator when the device is powered off.
In connected audio devices this could lead to the famous groundloop, which causes serious humming in the audio circuitry. Turning the plug about 180° sometimes solved the problem.

Edit: corrected on the ground / neutral subject

Re: Switch for PID

Posted: Thu Apr 25, 2019 10:22 pm
by Yummyrum
I think there is a bit of terminology error here . I think that the OP was meaning Neutral not Ground .

While talking about wiring up a vehicle we refer to Grounding one side of a device and connecting the other side to Hot or Live .

But when we talk about the US 110v or the Australian or UK 230v system we should refer to the Neutral wire as just that and not the Ground or Earth which although it is also bonded to the Neutral at the switch board , it does not carry the current . Its purpose is solely for protection against electrocution .

Good pickup NIN :thumbup:

Re: Switch for PID

Posted: Thu Apr 25, 2019 11:58 pm
by NZChris
I'm sure this switching subject has come up here earlier. Switching the neutral, but not the phase, can leave the equipment live if anything has gone wrong. Dangerous stuff.

Re: Switch for PID

Posted: Fri Apr 26, 2019 12:03 am
by Kindafrench
Yummyrum wrote:... and not the Ground or Earth which although it is also bonded to the Neutral at the switch board ...
Not the case here in France. It's an extra wire, very thick, which goes into the ground after leaving the switching board. Could imagine that it provides a better current leak detection in these Earth Leakage Circuit-Breakers / FI-circuit breakers. Although it is connected to the lightning arrester / surge protection, which is surely better than putting that lightning power on the neutral wire.

If no ground wire is at hand, people use the neutral as ground, too.
Yummyrum wrote:I think there is a bit of terminology error here . I think that the OP was meaning Neutral not Ground .
:shock: Sorry. I wanted to refer to neutral, not ground. Should read posts bit more focussed. Just got up and had a coffee that time.

Will be more careful when replying in the future.