Selector switch that automatically turns off when power's cut?

[kal]

Update: Got the relay and socket a few days ago and just finished wiring up and testing it out after double/triple checking everything. It works perfectly. The control panel cannot be turned on unless both pumps and elements are off.

Look for a "Control Panel (Safety addendum)" to be added to my TheElectricBrewery.com site some time in the near future that explains exactly how to use this extra part for added safety!

Kal

 

[CodeRage]

Glad you're happy with the results!

 

[kal]

Wish I could take credit for the latching relay but that is an incredibly common and useful circuit in controls.

So what would you call this sort of add-on circuit? I'm looking for the right wording to use on my website to describe it. Would calling it a "safety disconnect" be accurate?

Kal

 

[CodeRage]

Eh, its more of a start condition interlock or safe start interlock. Thats what I would call it any ways.

 

[kal]

Interlock! That's the word I was looking for.... "disconnect" is definitely not right as you said. Thanks!

Kal

 

[trigger]

Kal, thank you for making this thread, I never would have considered this otherwise. It seems like this is one of the more important safety features you could include on a multiple element brew rig to prevent dry fires.

I don't want to thread jack, but if you don't mind could you take a look at my latest wiring diagram here and see if I've put the interlock in correctly?

 

[kal]

I don't want to thread jack, but if you don't mind could you take a look at my latest wiring diagram here and see if I've put the interlock in correctly?

I'm afraid I don't understand that diagram. It has no information on the connections, so I have no idea if it'll do what you want it to do.

Kal

 

[trigger]

Sorry, I meant to link this post.

 

[BrewBeemer]

In case anyone's curious as to what an "octal base ice cube" relay is (I had to look it up), it's like this: Kal

I beg to differ Kal, that red cube in reply #22 that picture shows a 11 pin not a 8 pin. Oh what the hell do I know?

 

[CodeRage]

I beg to differ Kal, that red cube in reply #22 that picture shows a 11 pin not a 8 pin. Oh what the hell do I know?

oh, just a slight distinction, you'd figure it out real quick trying to stuff it in an octal base. hehe, nothing gets by the discerning eye of BrewBeemer!

11 pins are triple pole double throw in case you were wondering.

 

[kal]

Sorry, I meant to link this post.

That's better. Hard to read given it's split in two. Looking at it quickly I'm afraid I don't have the time to really go over it carefully to see if it makes sense. For me to say "yes it's ok" would probably require a dozen questions and an hour or two of careful review. Sorry, I just don't have the time. I need to get back to writing my own content for my site.

Kal

 

[trigger]

No problem, I totally understand. Thanks for looking and sorry about having to split the pics. Turns out nobody makes a decent circuit design program for Mac.

 

[kal]

Hi guys,

I've now finished documenting how I added a safe start interlock to my control panel.

See: http://www.theelectricbrewery.com/control-panel-safe-start-interlock

This safe start interlock only allows the control panel to power up if the pump and element switches are all in the OFF position. This interlock will also ensure that if power is ever cut, the pumps and elements will stay off until the operator turns them off and then resets the power.

Adding a safe start interlock to our control panel will avoid harming the pumps, heating elements, and the operator.

Cheers!

Kal

 

[Windsors]

Kal,

First off, let me say that you website is incredibly well done and a great resource. I am upgrading my electric brewery and am using a lot of your knowledge.

I am learning as I go, so I have what may be an off base question.

I have a similar relay (120 v coil) that I am using in a latching circuit as a push button start and the a separate push - pull NC 22 mm E stop.

Your safe start interlock is a great idea and one that I want to incoporate.

Question - Can I just use my latching relay setup E stop circuit and make the appropriate wiring changes from added contact blocks on my selector switches that you have done in your safe start system and have both the safe start interlock and still use the E stop ?

BTW, I didn't see where yours uses an E stop, and I am sure you covered that in the build thread some where.

Thanks in advance.

Bill

 

[kal]

Hi Bill!

I don't have an Emergency stop on my setup. At least not the style of mushroom button that is typically used. I have a on/off key switch.

It's really impossible for me to comment on if what you want to do will work with just a quick paragraph description like you mentioned. I'd suggest you start a new thread and post a schematic to see if people can comment. I'll keep a look out...

Kal