PID circuit question

[Keynes]

Hi,

I am currently designing a wiring diagram for a future PID control panel. My aim with the design is to have multiple circuits to reduce the load on each circuit (and bring it down to a 10amp load on each). With this in mind, would it be feasible to have 1 circuit to power 3 PID controllers, and two seperate circuits to power one 2400 watt and one 1800 watt elements? This way, the PID do not draw power from the element circuits and the active line on the element circuits will be switched by the SSR?

EDIT: I guess the question is whether the PID's add enough of a load to bother incorporating a third circuit to power them. I guess my motive is to provide headroom in case the 1800 watt element dies and needs to be replaced by an element with a higher wattage and to allow me to use more locations around the house serviced by 10amp power points.

Thanks!!

 

[QldKev]

PIDs use bugger all power. If you are going to use a pump, they draw a bit more. If you want to future proof it I would use three feeds, then the feed for the 1800w, PIDs and pump can be connected from a power-board. Then later if you up the 1800w to a 2400w element then you can just use a separate power source. This is how my 3V controller works. I have 4 power feeds, 3 being for running elements and the last for the PIDs and pump. The PIDs and pump line is shared in the brew area with my fridges etc so I can only draw a limited current from it.

 

[treefiddy]

What is the third PID controller for?

They use <5W power, you could get away with putting one on the 2400 W element circuit, but I would just put them on the 1800 W element circuit. If you update the element later on, it won't be too hard to change things around.

 

[Keynes]

PIDs use bugger all power. If you are going to use a pump, they draw a bit more. If you want to future proof it I would use three feeds, then the feed for the 1800w, PIDs and pump can be connected from a power-board. Then later if you up the 1800w to a 2400w element then you can just use a separate power source. This is how my 3V controller works. I have 4 power feeds, 3 being for running elements and the last for the PIDs and pump. The PIDs and pump line is shared in the brew area with my fridges etc so I can only draw a limited current from it.

I do plan on having a couple of pumps so I will add a third feed I think.

What is the third PID controller for?

They use <5W power, you could get away with putting one on the 2400 W element circuit, but I would just put them on the 1800 W element circuit. If you update the element later on, it won't be too hard to change things around.

Sorry, I was a bit inaccurate. I will have two PID's and a timer.

 

[QldKev]

Off topic, but my control panel does have 3. I use a PID on the kettle to leat me know when it's approaching the boil. Any thermometer could have done the job, I used a PID so it matched the other 2.

 

[macca05]

I have finally finished my brew controller but probably wont get a chance to use it as I am I the last few weeks of study and its bloody hard. I will post some pics of my build on my brew rig thread soon.
I set mine up for two circuits but have one pid and one element on each circuit. Plus on one is my pump and on the other it has a 12v transformer. I know witb tbe pump and eleme t it draws about 10.5a which should be ok for it. Will test it one day
Macca

 

[Keynes]

Thanks for your replies!!

With regards to the SSR, does it matter which terminal on the 240v side of the SSR is the load/element? (I have a feeling this may be a silly question...)

 

[QldKev]

Thanks for your replies!!

With regards to the SSR, does it matter which terminal on the 240v side of the SSR is the load/element? (I have a feeling this may be a silly question...)

Doesn't matter. But I use Fotek ones and I always wire mine up with the load on terminal 2, just as a wiring standard.

 

[rockeye84]

Do you have a 15a PowerPoint in your house? I have one for my hot water heater. Which is conveniently right near where I brew. So I built my system so it can pull 15a if needed one day. Just disconnect the hot water sys for a few hours while I brew. With one 2200w element, both pumps pids timers etc running it draws 10.1a leaving some headway to upgrade elements in the future. Nah doesn't really matter I rigged mine so it switched the active side, it just has to be in there somewhere so it can switch the element.