Wire elements direct to switches, PID/relay, or outlets?

[augiedoggy]

Ok, finally made it to what I initially needed to know! (my fault for sure for the lack of clarity, I'm learning and obviously trying to be overly cautious with the set up)

I can use my 10a selector switches to power on/off the contactors for the elements and I don't need to purchase the relays mentioned by bittersweet in #24, correct?

correct. if your contactors are 2 pole and 25a or more they are perfect to use as relays to ultimately turn on and off element power.

 

[WhiteArmadilloBrewing]

correct. if your contactors are 2 pole and 25a or more they are perfect to use as relays to ultimately turn on and off element power.

Beautiful. They are 240v 40a. Thanks for everyone's help!

 

[BitterSweetBrews]

DPST is fine. That's what I posted in #17 above. I agree about switching off both legs L1 and L2 of 240, it's a good idea.

DPST is correct and fine. My fingers got the best of me when typing.

 

[BitterSweetBrews]

Beautiful. They are 240v 40a. Thanks for everyone's help!

Good Luck. Keep us posted.

 

[BitterSweetBrews]

correct. if your contactors are 2 pole and 25a or more they are perfect to use as relays to ultimately turn on and off element power.

Agree. Contactors are essentially relays. They are usually used for higher amperages.

 

[BitterSweetBrews]

Sorry, I should've provided a few additional details. I will run (2) Auber EZBoils to control RIMS Mash and BK. In between the EZBoil and the elements there will be contactors, fuses, circuit breakers, and SSRS. What I'm asking is if I should wire the elements to a simple manual selector switch and control the on/off manually or wire the elements through that series of safeguards to be controlled (on/off/cycled) by the PID?

toggle switches that flip 30 amp DPDT relays to connect the power lines. Make sure you use DPDT, you do not want to only flip 1 wire. This will immediately disconnect power from the elements should you get close to a boil-over and can't adjust your PIDs fast enough. It also allows you to conserve bezel space. If you are flipping a relay you could use light switches, but you can buy smaller 15A/120V toggle switches that would take up a lot less space.

I should have typed DPST relays.

Also, I didn't realize your "Contactors" were actually high amp relays.

I don't know if someone else addressed this and maybe it is in the schematic. You should wire your element contactors/relays after your PID/EZBoils & SSRs, but before the elements (outlets).

 

[augiedoggy]

I should have typed DPST relays.

Also, I didn't realize your "Contactors" were actually high amp relays.

I don't know if someone else addressed this and maybe it is in the schematic. You should wire your element contactors/relays after your PID/EZBoils & SSRs, but before the elements (outlets).

Curious, why do you suggest its better to wire them after the ssrs that way the ssrs are one and active whenever the panel has power right? other than that it just offers the ability to shut off that output during brewing if there some sort of meltdown or failure of the ssr and use another element output temporarily to finish the brewday with piece of mind knowing that ssr no longer has ac power going to it.

 

[BitterSweetBrews]

Curious, why do you suggest its better to wire them after the ssrs that way the ssrs are one and active whenever the panel has power right? other than that it just offers the ability to shut off that output during brewing if there some sort of meltdown or failure of the ssr and use another element output temporarily to finish the brewday with piece of mind knowing that ssr no longer has ac power going to it.

I like to wire my relays on the wires from the SSR to the power outlets themselves, after all the electronics. I think that it lessens the chance of a surge or spike to the SSR from me switching outlet power off/on. The power to the SSR comes from the PID and it doesn't really matter to me if it is cycling the AC to nowhere.

On my new controller, I have my PID wired through the SSR to both the 240v and 120v outlets. I have it wired so I can run the L6-30 outlet at either 240v or 120v. I have the hot line controlled by the SSR going to both the L5-20 and L6-30 outlets. Regardless of the state of the L6-30 outlet, the L5-20 is always on 120V, (the other side of it is the common wire). Both are shut off by the relays when the DPDT toggle switch is in the middle. I have a 120v outlet relay and a 240v outlet relay. If I want my 120v RIMS outlet controlled by the PID, I would just swap the Boil or HLT kettle sensor plug for the RIMs sensor plug.

I do have an un-switched outlet on the controller that I could plug my other 120v stand-alone controller into. I could then run the RIMS from its PID and leave the HLT heating sparge water with this controller until I was ready to boil.

 

[doug293cz]

I like to wire my relays on the wires from the SSR to the power outlets themselves, after all the electronics. I think that it lessens the chance of a surge or spike to the SSR from me switching outlet power off/on. The power to the SSR comes from the PID and it doesn't really matter to me if it is cycling the AC to nowhere.

...

No, the power to the SSR comes from the AC lines. The PID only provides a low voltage, low current DC control signal to the SSR. Also, SSR's are designed to handle inductive loads (motors, etc.), and have built in snubber circuits to absorb voltage spikes, and resistive loads don't spike when switched. Like @augiedoggy , I recommend putting the element contactors on the power input side of the SSR's rather than on the load side of the SSR's. This way you can electrically isolate (disconnect) the SSR completely from the lines voltage in case of failure. All my designs are done this way.

Brew on

 

[BitterSweetBrews]

No, the power to the SSR comes from the AC lines. The PID only provides a low voltage, low current DC control signal to the SSR. Also, SSR's are designed to handle inductive loads (motors, etc.), and have built in snubber circuits to absorb voltage spikes, and resistive loads don't spike when switched. Like @augiedoggy , I recommend putting the element contactors on the power input side of the SSR's rather than on the load side of the SSR's. This way you can electrically isolate (disconnect) the SSR completely from the lines voltage in case of failure. All my designs are done this way.

Brew on

Either way works.

I like switching the load side rather than the power. This is how I have always designed the circuits. I think manually switching power on and off with a contactor/relay can create spikes that would decrease SSR life and hurt it more then leaving it on.

One school of thought, coinciding to yours, says put the relay as far upstream as possible to cut power to more things.

As I said, I like having my relays between the outlet and the SSR, especially since I split them between two relays on the L6-30 and the other L5-20 outlet. Even if the SSRs can handle loads and spikes, I choose not to even give them a chance to happen.