Modifying still dragon controller

[matt2778]

I'm currently in the process of doing a basement brewery build and as costs build up I'm looking to build the controller on the cheap. I have the 30 amp 240 volt outlet in place, and the still dragon controller is in the mail. I'd like to be able to modify the controller to run both the boil kettle and the hlt without unplugging 30 amp cords. Is it as simple as taking the power to element and running it to three way switch
http://www.ebrewsupply.com/shop/indicators-switches/2-3-way-switches/3-way-1-no-contact-switch.html
Then wiring that to a couple of twist locks? Or am I missing something.


Thanks,
Matt

 

[doug293cz]

I'm currently in the process of doing a basement brewery build and as costs build up I'm looking to build the controller on the cheap. I have the 30 amp 240 volt outlet in place, and the still dragon controller is in the mail. I'd like to be able to modify the controller to run both the boil kettle and the hlt without unplugging 30 amp cords. Is it as simple as taking the power to element and running it to three way switch
http://www.ebrewsupply.com/shop/indicators-switches/2-3-way-switches/3-way-1-no-contact-switch.html
Then wiring that to a couple of twist locks? Or am I missing something.


Thanks,
Matt

You're not the first to want to do this. Check out this thread (starts on the 3rd page) https://www.homebrewtalk.com/f170/stilldragon-diy-controller-kit-441611/index5.html#post6780005. For the switching you want to do, you need a double pole, triple throw (ON-OFF-ON) switch rated at 30A @ 250V (or higher.) Not so easy to find low cost switches like that. I spent about an hour searching, and came up empty.

Brew on

 

[passedpawn]

You could use a DPDT switch, like this one from Amazon: http://www.amazon.com/dp/B003A3W41C/?tag=skimlinks_replacement-20. It's break-before-make, which means the center is off.

The far easier way to switch the control signal from one SSR to the other. Yep, you'd need another SSR. The control signal from the controller is low voltage, prolly 5 or 12V DC. Switch that from one SSR to the other.

I prefer dual SSRs that turn off both hot legs of the 240V service, but technically it's not necessary.

 

[Brumateur]

It takes only1 minute to find a proper switch - http://www.ebay.com/itm/AC-660V-32A...-Selector-Cam-Changeover-Switch-/190818503022

 

[doug293cz]

The far easier way to switch the control signal from one SSR to the other. Yep, you'd need another SSR. The control signal from the controller is low voltage, prolly 5 or 12V DC. Switch that from one SSR to the other.

The StillDragon controller uses a potentiometer controlled SSVR, so switching the control signal is not an option.

Brew on

 

[passedpawn]

The StillDragon controller uses a potentiometer controlled SSVR, so switching the control signal is not an option.

Brew on

Woops, sorry, you're right.

 

[doug293cz]

You could use a DPDT switch, like this one from Amazon: http://www.amazon.com/dp/B003A3W41C/?tag=skimlinks_replacement-20. It's break-before-make, which means the center is off.

It takes only1 minute to find a proper switch - http://www.ebay.com/itm/AC-660V-32A...-Selector-Cam-Changeover-Switch-/190818503022

Obviously, I need to work on my search skills. :smack: I didn't find anything like either of these, either of which looks like it would work. The amazon choice is however fairly expensive.

Brew on

 

[Paps]

These `still dragon` SSR`s can be hooked up to a PID controller right?

 

[doug293cz]

These `still dragon` SSR`s can be hooked up to a PID controller right?

No. They are potentiometer controlled SSVR's with analog inputs. They do not have digital inputs.

Brew on

 

[Brumateur]

The StillDragon controller uses a potentiometer controlled SSVR, so switching the control signal is not an option.

Brew on

Why not? You still can do it with DPDT switch.

 

[Brumateur]

These `still dragon` SSR`s can be hooked up to a PID controller right?

Yes it can, but you need to use a relay output or additional circuitry.

 

[doug293cz]

Yes it can, but you need to use a relay output or additional circuitry.

Yes, you can put a PID with a relay output (like an Auber SYL-2342) in series with the potentiometer that controls the SSVR. I would be concerned about the duty cycle of the PID's relay leading to early wear out. If you want to control with a PID, it seems better to just use a regular SSR hooked up to the PWM voltage output of the PID.


Image from https://www.homebrewtalk.com/f170/switching-5500w-element-between-120v-240v-461607/#post5938791

What you cannot do (without an external relay or other control circuitry) is hook up the PWM voltage output of a PID to an SSVR's potentiometer terminals. For example an Auber SYL-2352 cannot be connected directly to an SSVR.

Brew on