Why so many switches, led, and relays??

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

christpuncher123

Well-Known Member
Joined
May 1, 2009
Messages
187
Reaction score
12
Location
Kingston
It seems to me that there is a lot of unnecessary pieces in most peoples EBIAB Builds. Don't get me wrong I think these things are awesome but has nobody built any simple versions? Why have a switch for the heat, should the temperature controller not do that? Turn the PID on you have heat, turn it off you don't! Same for the pump, plug it in it's on, unplug it its off! Can I just use a 30Amp Gfci breaker on my dryer or stove circuit? I love all these high tech an Shinny builds, but I want this thing to do one thing, make the great beer that I have been making for years:tank:!!
 
Kal made a brewery and reference design that was above and beyond most 'needs' because his #1 concern wasn't cost, it was safety. There are a few extra switches... like you don't need a switch under each PID if you don't want to allow each of them to trip the alarm, the switch for the pumps is necessary as you don't want to plug the motor in hot and have it running when you unplug, it will spark and isn't as safe as it could be.

now some of the more recent builds have been putting in breakers for each line, not necessary, but they are there for added protection, and so they don't trip their big breaker which could be in the basement - far away from the garage.

Keep looking on the site, there are plenty of simplified builds, but it won't look as cool, or have as much functionality.

-Matt
 
The switch for the pump makes sense. I am fortunate enough to have a pump out of a hydronic furnace I just removed! Now to see what other parts I can round up!
 
Kal made a brewery and reference design that was above and beyond most 'needs' because his #1 concern wasn't cost, it was safety. There are a few extra switches... like you don't need a switch under each PID if you don't want to allow each of them to trip the alarm, the switch for the pumps is necessary as you don't want to plug the motor in hot and have it running when you unplug, it will spark and isn't as safe as it could be.

now some of the more recent builds have been putting in breakers for each line, not necessary, but they are there for added protection, and so they don't trip their big breaker which could be in the basement - far away from the garage.

Keep looking on the site, there are plenty of simplified builds, but it won't look as cool, or have as much functionality.

-Matt

Matt,

I see a bunch of people using switches to power on their PID's, this seems overkill. Why does it matter if they are on, especially if you have a switch that will control power to the element. I am all for safety, but let's face it, there is enough electricity running through a household light switch to make it a bad day and I don't have redundancies there. I accept I am new to this and may be missing something...
 
Matt,

I see a bunch of people using switches to power on their PID's, this seems overkill. Why does it matter if they are on, especially if you have a switch that will control power to the element. I am all for safety, but let's face it, there is enough electricity running through a household light switch to make it a bad day and I don't have redundancies there. I accept I am new to this and may be missing something...

I thought the same thing, then when I dove into Kal's design, the switch underneath each PID isn't to turn it on/off, it is to arm the alarm, so your alarm will turn on when your set point temp is hit (like when your water is at 163 degrees and ready for mash in). This is helpful if you turn it on, walk away and want to be informed when it is ready to get to the next brew stage.
 
I thought the same thing, then when I dove into Kal's design, the switch underneath each PID isn't to turn it on/off, it is to arm the alarm, so your alarm will turn on when your set point temp is hit (like when your water is at 163 degrees and ready for mash in). This is helpful if you turn it on, walk away and want to be informed when it is ready to get to the next brew stage.

So to be clear, we are on the same page. No need for a Switch to turn on the PID?
 
correct, just the main power to the entire unit, someone else that has completed their design can step in and correct me if I am wrong.
 
Without getting too deep into the topic, the idea of unplugging something to turn it off is just bad design when you have electricity operating in or near water. I'd say most full on control panels put safety first, convenience second. You can heat water with electricity with a LOT less, but this is one place where going overboard is generally a good idea.
 
Why have a switch for the heat, should the temperature controller not do that? Turn the PID on you have heat, turn it off you don't!

No one has addressed this so I will - the PID controls the SSR, and tells it when to turn on and off. The SSR controls ONE leg of the 240v (Assuming your heating element is 240v).

The second leg is always hot. Further, SSRs have been known to leak some amount of current, and that amount can be more than you'd expect. Additionally, they have been known to fail in the closed (IE on) position. All of these scenarios are bad.

So people put in a switch to manually cut power between the SSR and the element. Whether it's a heavy duty 30a rated switch that your lines run through, or a smaller switch that goes to a 30a rated relay, that's up to you. But again, it's safer than unplugging the element every time.

now some of the more recent builds have been putting in breakers for each line, not necessary, but they are there for added protection, and so they don't trip their big breaker which could be in the basement - far away from the garage.

I'm going to disagree with you there Matt. Think of it this way - you have one main breaker to your house, probably 100 or 200A - why have a bunch of 15 and 20A breakers? The answer is not for convenience. I'm running 6ga wire off a 50A breaker to my panel, which are paired for each other. The 6ga wire cannot handle more than 50A which is why I have it paired to an appropriately sized breaker so the breaker will trip first.

Inside the panel, I have 10 and 14ga wires. If you were right, those wires would be allowed to try and carry 45A without the breaker ever tripping, but if you try and pump 45A through a 14ga wire... well, you'll let out the black smoke for sure and possibly cause further damage.

You want a breaker sized to protect the wiring that is down-stream of that wire. Whether you use a fuse or a breaker, it should be protected from overloading the current carrying capacity of the wire.


As for the other flashy lights and gizmos - they're just fun. I have seen a few builds on here that were VERY simple - single PID in a small box, no lights, nothing flashy. You could easily do something like that.

-Kevin
 
No one has addressed this so I will - the PID controls the SSR, and tells it when to turn on and off. The SSR controls ONE leg of the 240v (Assuming your heating element is 240v).

The second leg is always hot. Further, SSRs have been known to leak some amount of current, and that amount can be more than you'd expect. Additionally, they have been known to fail in the closed (IE on) position. All of these scenarios are bad.

So people put in a switch to manually cut power between the SSR and the element. Whether it's a heavy duty 30a rated switch that your lines run through, or a smaller switch that goes to a 30a rated relay, that's up to you. But again, it's safer than unplugging the element every time.



I'm going to disagree with you there Matt. Think of it this way - you have one main breaker to your house, probably 100 or 200A - why have a bunch of 15 and 20A breakers? The answer is not for convenience. I'm running 6ga wire off a 50A breaker to my panel, which are paired for each other. The 6ga wire cannot handle more than 50A which is why I have it paired to an appropriately sized breaker so the breaker will trip first.

Inside the panel, I have 10 and 14ga wires. If you were right, those wires would be allowed to try and carry 45A without the breaker ever tripping, but if you try and pump 45A through a 14ga wire... well, you'll let out the black smoke for sure and possibly cause further damage.

You want a breaker sized to protect the wiring that is down-stream of that wire. Whether you use a fuse or a breaker, it should be protected from overloading the current carrying capacity of the wire.


As for the other flashy lights and gizmos - they're just fun. I have seen a few builds on here that were VERY simple - single PID in a small box, no lights, nothing flashy. You could easily do something like that.

-Kevin

Good points about the breakers in line.
 
No one has addressed this so I will - the PID controls the SSR, and tells it when to turn on and off. The SSR controls ONE leg of the 240v (Assuming your heating element is 240v).

The second leg is always hot. Further, SSRs have been known to leak some amount of current, and that amount can be more than you'd expect. Additionally, they have been known to fail in the closed (IE on) position. All of these scenarios are bad.

So people put in a switch to manually cut power between the SSR and the element. Whether it's a heavy duty 30a rated switch that your lines run through, or a smaller switch that goes to a 30a rated relay, that's up to you. But again, it's safer than unplugging the element every time.

Which is exactly why Kal's design uses a mechanical relay between the PIDs & the SSRs which I appriciate. I have first hand experience with an SSR that failed closed!

This is not a luxury it's a nessessity! :mug:
 
I'm not familiar with Kal's schematic, but to clarify, I'm sure the mechanical relay is between the power and the SSR, not the PID and the SSR. Simply cutting off the signal voltage to the SSR would not stop current leakage or a failed SSR stuck in the on position. I'm pretty sure this is what you meant.
 
Agreed. The mechanical disconnect, whether a 30A switch or a contactor, is between the SSR and the outlet for the element.
 
gunmetal said:
I'm not familiar with Kal's schematic, but to clarify, I'm sure the mechanical relay is between the power and the SSR, not the PID and the SSR. Simply cutting off the signal voltage to the SSR would not stop current leakage or a failed SSR stuck in the on position. I'm pretty sure this is what you meant.

Yes , tied to the Element select switch so you're not just relying on the pid to fire the Element.
 
I'm going to disagree with you there Matt. Think of it this way - you have one main breaker to your house, probably 100 or 200A - why have a bunch of 15 and 20A breakers? The answer is not for convenience. I'm running 6ga wire off a 50A breaker to my panel, which are paired for each other. The 6ga wire cannot handle more than 50A which is why I have it paired to an appropriately sized breaker so the breaker will trip first.

Inside the panel, I have 10 and 14ga wires. If you were right, those wires would be allowed to try and carry 45A without the breaker ever tripping, but if you try and pump 45A through a 14ga wire... well, you'll let out the black smoke for sure and possibly cause further damage.

You want a breaker sized to protect the wiring that is down-stream of that wire. Whether you use a fuse or a breaker, it should be protected from overloading the current carrying capacity of the wire.

-Kevin

I don't disagree with your explanation of what branch breakers are meant to do. However, I consider a brewing control panel and its associated heating elements to be acting as a single appliance. The resistive loads you design into this system are going to be very predictable. You used an example of a 14g wire trying to carry 45 amps, but you didn't explain a scenario where that would happen.

Let's say you have a 50amp breaker supplying the panel and the load break down is going to be two 5500w elements (sometimes run simultaneously), two pumps, and a couple PIDs. If the two element legs are just run off of distribution blocks and safety switched via contactors, what is the worst case scenario? That's a big 6/4 SJ cord going into the panel and splitting off to two sets of 10/3 SJ coming out. Let's assume everything downstream of the main distro block is 10g. Each element is going to pull 23 amps. I'm trying to figure out a situation where one element would pull something like 40a. Perhaps a really bad connection at the element?

I generally feel that you'd want to protect your PIDs from overcurrent with cheap, replaceable inline fuses, but I don't agree that branch breakers dedicated to each element is less than overkill on the safety side. Sure, safety is the one place where overkill is acceptable but I wouldn't say excluding them is particularly dangerous unless you're automating to the point where the whole batch will brew itself while you're not home.

Does anyone know if modern electric stoves have separate breakers for all 6 elements?

It's important to note that this is not advice. If you don't know what I'm saying, you should er on the side of safety and consult an electrician.
 
Valid points, Bobby. I can't honestly say if the electric stoves have breakers, fuses, or nothing. I can't really think of a scenario off hand where my wiring will see unexpected loads, but I'm also not sure what routine scenarios would exist to cause the GFCI to trip but I've got one of them, too.

I guess for me it's the fact that these panels are wired up by amateurs using a mix of parts that surely haven't been tested / listed together as a system, and may not be listed at all... so there's no guarantee that everything will function properly so why not buy yourself a little extra security.
 
My understanding is that best practice is to protect the wiring with breakers or fuses, because in a worst case scenario the device drawing power could fail catastrophically and exceed its normal maximum amperage draw. Seems pretty easy to do in these applications, so I cannot see why one would skip it.
 
On a safety stand point. How many people do brews on their stove? Is there Gfci Protection on your stove?

No - But then the stove has not been wired by a mystery man trying to build something that he has no clue about doing so.

Plus the stove has been certified and approved before the fabrication of it.

I suggest that all of the naysayers get real. This whole game is playing "You Bet Your Life!"


Get over it....!!!!
 
Great now I'm paranoid! I'm going to home depot to get a bunch of gfci's for my water heater, washing machine, keureg, and the 7 gallon coffee urn at the office!
 
On a safety stand point. How many people do brews on their stove? Is there Gfci Protection on your stove?

Your stove is built and assembled as a complete unit, and if you purchased it in the US it is tested and listed by Underwriters Laboratories and / or Factory Mutual to safely function as a stove.

Until one of us goes and gets our hodge-podged control panel / brewery setup tested and listed by UL and production standards are monitored by the Consumer Products Safety Commission, I don't see it as a fair comparison.

-Kevin

Well damn... P-J beat me to the punch...
 
...
Well damn... P-J beat me to the punch...

ROTFLMAO.gif
 
It seems to me that there is a lot of unnecessary pieces in most peoples EBIAB Builds. Don't get me wrong I think these things are awesome but has nobody built any simple versions? Why have a switch for the heat, should the temperature controller not do that? Turn the PID on you have heat, turn it off you don't! Same for the pump, plug it in it's on, unplug it its off! Can I just use a 30Amp Gfci breaker on my dryer or stove circuit? I love all these high tech an Shinny builds, but I want this thing to do one thing, make the great beer that I have been making for years:tank:!!

I went the easy analog route. 30 amp gfi. Two receptacles, one for the HLT (a 20 liter/1300 watt water tank with its own rheostat and switch) and a plain old switched one for the 4500 watt element in the 36 liter BK. The boil in the kettle is perfect, no need for adjustment (works out to about 3400 watts for me on my grid here in Japan).
 
I think there's a lot of "extra" or "nice to have" stuff in a lot of the panels I've seen on here. Heck even mine has some :p.

I actually ordered a 2nd temp probe & PID for the MLT thinking I was going to use it to control recirculation during the mash (so I could maintain different temps in HLT & MLT). Ended up opting against that so now I have a pricy thermometer ;). Maybe I'll change my mind down the road though - who knows.

Another thing while building my most recent panel was some of the lights - do I really need pump lights & pump switches & the obvious noise from the pumps running (3x indicators that the thing is on)? I opted to go with the lights because I was like "Eh... it's like $4 why not?" but I don't see how they are a legit safety feature :p.

I do think indicator lamps for the elements are a real safety feature though. There's no other real obvious indicator of when the thing is firing that I could see at a glance from the other side of the room.

I definitely left out the volt meter, ammeter, panel-mount timer, & stuff like that though.
 
Great now I'm paranoid! I'm going to home depot to get a bunch of gfci's for my water heater, washing machine, keureg, and the 7 gallon coffee urn at the office!

You should, if you start stirring your water heater, washing machine, or coffee with a metal mash paddle or metal spoon while they are on.
 
For me - I have two pumps, so knowing wich is on and which isn't can't be done by sound alone - quick glimpse at the panel tells me. Also, you're spot on with the element light - I was running my first full volume test (water) yesterday and I heared weird noises, but a quick check of the panel told me it was the sound of the element firing, and it was easy to confirm wich one.

Really, I think the GFCI and breakers and EPO are the only safety features. The rest are nice-to-haves... if I dry fire an element or run a pump dry and kill them, I'm not hurting anyone or doing anything 'unsafe' - just stupid.
 
Point taken about the breakers and especially with reconsideration given the average person building the systems (myself included) having a high chance of screwing something up in the design, build and regular operation. It's probably a good idea to always recommend the breakers or at least fuses.
 
I actually ordered a 2nd temp probe & PID for the MLT thinking I was going to use it to control recirculation during the mash (so I could maintain different temps in HLT & MLT). Ended up opting against that so now I have a pricy thermometer ;).

Do you want to sell the 2nd ones cheap?
 
Do you want to sell the 2nd ones cheap?

Nah, but thanks for the offer.

Never know what I might end up using it for in the future. I like horsing around with my equipment nearly as much as brewing... plus it makes a pretty snazzy thermometer! :mug:
 
I use a Control Panel On/Off switch, an Element On/Off Switch, and a PID.

CP Switch turns the panel on (aka, PID turns on)
Element Switch allows current to the Element (aka, PID fires element)

It's about as bare bones as I think you can safely get... And I love it!


I also have an extension cord with a switch for the pump.
 
I use a Control Panel On/Off switch, an Element On/Off Switch, and a PID.

CP Switch turns the panel on (aka, PID turns on)
Element Switch allows current to the Element (aka, PID fires element)

It's about as bare bones as I think you can safely get... And I love it!


I also have an extension cord with a switch for the pump.

Picture?
 
This is the best I have for now. It's from my phone, so be nice... I'll be posting my build thread soon. Just gotta take real pictures first.

The CP is on the left. System is a 20gal Single Vessel BIAB with recirc and counterflow chilling. Top switch is System On/Off, bottom switch is Element On/Off.

setup.jpg


electrical2.jpg
 
There was some discussion earlier in this thread about the need for additional over-current protection (fuses or circuit breakers) on the individual circuits controlled by a panel. The comparison was made to an electric range and there was discussion of whether they have over-current protection for individual circuits.

Generally, an electric range doesn't have any additional protection on the individual circuits. Yes, a failure could overload a wire in the range but it is inside the range, an enclosure designed to limit the spread of the fire. A brewing control panel is similar up until the point where a cord is used to connect an external device to it.

Imagine a panel with a properly protected 50A feed and no additional over-current protection on the individual circuits. Now imagine a pump circuit coming out of that panel. Finally, imagine that pump motor seizes and the over-temperature protection in the motor fails to turn it off (not unheard of). Now you have a small guage cord and motor overloaded with only a 50A breaker for protection. That breaker won't trip and the cord/motor will continue to heat. Eventually something starts to burn and it isn't inside a fire resistant enclosure.

That is why it is important to have properly sized over-current protection on all of the circuits coming out of the panel.
 
That breaker won't trip and the cord/motor will continue to heat. Eventually something starts to burn and it isn't inside a fire resistant enclosure.

That is why it is important to have properly sized over-current protection on all of the circuits coming out of the panel.
That sounds like what an insurance company will tell you when they refuse to pay for damages. If they can't sue the manufacturer (YOU) then they're not going to pay. When the bank comes looking for their money for the house that burned down, the insurance company will be wagging the finger at the homeowner. It pays to protect yourself.
 
Matt,

I see a bunch of people using switches to power on their PID's, this seems overkill. Why does it matter if they are on, especially if you have a switch that will control power to the element. I am all for safety, but let's face it, there is enough electricity running through a household light switch to make it a bad day and I don't have redundancies there. I accept I am new to this and may be missing something...

Let me put the switch in perspective with an example from actual industrial controls. When controlling temperature with steam it's common practice to put a 2 position valve (open or closed) in line with the control valve. The 2 position valve must be open in order for the control loop (PID) to control temperature. It's done this way for 2 reasons - control valves can be prone to slight leakage and it prevents the media from being heated in the event the control loop is inadvertently left in auto or manual and not 0% open. Both conditions can lead to safety issues. I've seen installs where the customer did it on the cheap and next thing you know something was damaged because a 350 degree hotspot was created since the control valve was left 100% open but the product side of the heat exchanger was not flowing.

In the case of the switch, it's there to prevent dry firing the heating element Think of it as the same as the discrete valve. If you forget to set the PID control loop to 0% and manual but turn the switch off, you won't dry fire the heating element, which can both ruin the element and be dangerous in terms of burning something.

Sure, you can eliminate it but I would keep it there. It's a lot easier to remember to flip the switch than to put the control loop into manual and 0% open.
 
Let me put the switch in perspective with an example from actual industrial controls. When controlling temperature with steam it's common practice to put a 2 position valve (open or closed) in line with the control valve. The 2 position valve must be open in order for the control loop (PID) to control temperature. It's done this way for 2 reasons - control valves can be prone to slight leakage and it prevents the media from being heated in the event the control loop is inadvertently left in auto or manual and not 0% open. Both conditions can lead to safety issues. I've seen installs where the customer did it on the cheap and next thing you know something was damaged because a 350 degree hotspot was created since the control valve was left 100% open but the product side of the heat exchanger was not flowing.

In the case of the switch, it's there to prevent dry firing the heating element Think of it as the same as the discrete valve. If you forget to set the PID control loop to 0% and manual but turn the switch off, you won't dry fire the heating element, which can both ruin the element and be dangerous in terms of burning something.

Sure, you can eliminate it but I would keep it there. It's a lot easier to remember to flip the switch than to put the control loop into manual and 0% open.

For the brewing application, this is better accomplished by running the hot output of the SSR and the other hot output (assuming 240V) through a double pole switch or contactor. Assuming one does this and also has a switch or contactor to cut main power, I do not see any utility to having a switch to turn off the PID. If you want everything off including the PID, cut main power. If you want to make sure the element is off, cut element power. You can then run your other circuits (pumps, etc.) with the PID on but no power to the element.
 
Back
Top