HERMS Electronics?

[TAD]

Good afternoon Gentlemen,

I am trying to get the plans for my HERMS brewery together and since I already have a Ranco temperature controller and a 240V heating element I have decided to go electric on my HLT. The problem is I don’t know that much about electricity and have some questions for whoever would be willing to help.

1: I have seen many people say they also have a 240V heating element but they are only running it on 120V. Does this just mean plugging your 240V element into a 120V outlet, or does there need to be some kind of resistor incorporated into the circuit?

2: I don’t know anything about Solid State Relays, Heat Sinks, or PID controllers. I’d like any thoughts about what is necessary, what isn’t and why.

Thank you in advance for any advice and keep on brewing.

 

[illin8]

If you run a 240v heating element on 120v service, you end up with an output of 1/4 of the wattage that your element is designed for. In other words, a 5,500 watt element would be putting out 1,375 watts. So there is a significant loss there.

If you have a 240v element you'd be better served with a PID controller...do a search.

 

[TAD]

Thank you for your response. That’s one of the things I love most about this forum. But;

1: I think my element is only 4500 watts at 240V. Is the problem with running the element at around 1125 watts that it will take a long time to heat my water? Are we talking like 2 hours for 5 gallons?

2: I have done many searches on the subject. I can’t figure out if I would need to incorporate a solid state relay and/or a heat sink into this system. I think I understand that a solid state relay is just a switch with no mechanical movement, therefore reducing heat. But I’ve also read about people SSRs driving their heating elements and don’t know what this means. Is it somehow providing more amperage for the element, and if does why is this desired?

3: I have seen my options for solid state relays (25A, 40A) but don’t know how to calculate how much amperage my system would be using.

4: My Ranco can use multiple temperature probes connected in series and it will read the average temp of all of them. I have not seen a PID that states this as a feature. Does any one know if any/all PIDs are capable of this?

Thanks again,

 

[homebeerbrewer]

TAD, I'm not gonna be much help, but I might be able to answer at least one question. A relay functions as an electrically operated switch. If your PID runs on, say 12v, and your heating element runs on 240v, you'll need the relay. The PID activates the relay, which in turn powers up the heating element.

Does that make sense?

 

[jcdillin]

Yes it's going to take a while at 1125 watts, your going to want to insulate the heck out of your HLT if you want it to be able to remotely keep up. For that I would pick up a 1500W or 2000w 120v element from homedepot or run a 220v line.

You divide the wattage with the voltage to find your amperage. So 1125 / 120 = 9.375 AMPS.

Thank you for your response. That’s one of the things I love most about this forum. But;

1: I think my element is only 4500 watts at 240V. Is the problem with running the element at around 1125 watts that it will take a long time to heat my water? Are we talking like 2 hours for 5 gallons?

2: I have done many searches on the subject. I can’t figure out if I would need to incorporate a solid state relay and/or a heat sink into this system. I think I understand that a solid state relay is just a switch with no mechanical movement, therefore reducing heat. But I’ve also read about people SSRs driving their heating elements and don’t know what this means. Is it somehow providing more amperage for the element, and if does why is this desired?

3: I have seen my options for solid state relays (25A, 40A) but don’t know how to calculate how much amperage my system would be using.

4: My Ranco can use multiple temperature probes connected in series and it will read the average temp of all of them. I have not seen a PID that states this as a feature. Does any one know if any/all PIDs are capable of this?

Thanks again,

 

[Bobby_M]

Some more data for you. If you run 4500w unit on a 240v supply, it's pulling 18.75 amps. I think you need a 30amp breaker and some 10/4 SJ cord for your supply.

Your ranco will not switch that kind of amperage at 240v as far as I know so you'll need a 30amp SSR with a 120v control. You'd run 120v into that, interrupted by the ranco. I really don't know what I'm talking about though.

 

[TAD]

TAD, I'm not gonna be much help, but I might be able to answer at least one question. A relay functions as an electrically operated switch. If your PID runs on, say 12v, and your heating element runs on 240v, you'll need the relay. The PID activates the relay, which in turn powers up the heating element.

Does that make sense?

Does this mean that I can be plugged into a 120v outlet, use a 12v PID (120-12=108), incorperate a 40A SSR, and be able to ran my element at 4320 watts (108*40=4320)? Is that how this works?

 

[Bobby_M]

No, not at all. Elements are resistive devices so the power you get out of it is related to the voltage they are supplied. You have two choices, 120 or 240. The current they pull (amps) is an effect, not something you can change.

 

[TAD]

Some more data for you. If you run 4500w unit on a 240v supply, it's pulling 18.75 amps. I think you need a 30amp breaker and some 10/4 SJ cord for your supply.

Your ranco will not switch that kind of amperage at 240v as far as I know so you'll need a 30amp SSR with a 120v control. You'd run 120v into that, interrupted by the ranco. I really don't know what I'm talking about though.

I appreciate the advice but I don’t quit follow you. What do you mean a 120v control?

 

[ClaudiusB]

I appreciate the advice but I don’t quit follow you. What do you mean a 120v control?

OK Tad,
Two type of SSRs are available, DC or AC turn on control.
The DC control type requires a 3-32 DC voltage to turn on the SSR.
The AC type can be turned on with your standard 120 V from the outlet.


Cheers,
ClaudiusB

 

[TAD]

No, not at all. Elements are resistive devices so the power you get out of it is related to the voltage they are supplied. You have two choices, 120 or 240. The current they pull (amps) is an effect, not something you can change.

So, if I used a 120v outlet for the whole temp control system (PID, SSR, and element) the element would still be receiving 120v. Correct?

 

[illin8]

1: I think my element is only 4500 watts at 240V. Is the problem with running the element at around 1125 watts that it will take a long time to heat my water? Are we talking like 2 hours for 5 gallons?

It will take a while, IMO you'd be better off with 240V. If you connect to your standard home outlet it's 110 or 120 V. Appliances such as electric dryers, electric stoves/ranges, require 220 or 240v power which have the larger specialized outlets (larger with 3 or 4 round prongs). So if you connect your 4,500 watt element to 120, you'll get 1,125 watts of heating power (25% of what it is capable of) and will be pulling 10.3 amps. If you connect to 240v, you'll get the full 4,500 watts and will be pulling 18.75 amps. Be sure that the amount of electricity being pulled (amps) isn't much more than 80% of what the circuit is rated for. For instance, a 5,500 watt element on 240v pulls 23 amps, which should be connected to a 30 Amp GFCI protected circuit.

2: I have done many searches on the subject. I can’t figure out if I would need to incorporate a solid state relay and/or a heat sink into this system. I think I understand that a solid state relay is just a switch with no mechanical movement, therefore reducing heat. But I’ve also read about people SSRs driving their heating elements and don’t know what this means. Is it somehow providing more amperage for the element, and if does why is this desired?

A PID acts as a temperature controller that receives input temperature readings from a temp sensor. It sends a 12v DC signal to an SSR (Solid State Relay) which controls power to the element. You can set the PID to a specific temperature and the PID will tell the SSR to give the element full power (100%) until the temp is reached, at which point the PID simply maintains that temp. You can also use the PID in manual mode where you set the power of the element as a percentage (50% for example). This is used mostly to maintain a rolling boil (at 50%) versus a Mt. St. Helens eruption of boiling wort flying out of the kettle (at 100%). The PID sends 12v DC current to the SSR to turn the element on for 50% of the time...so in a one second interval the element would be on 100% for 1/2 second and completely off for 1/2 second and would cycle continuously like this. One thing to keep in mind is that the SSR connects the 240v power to the element...the PID simply tells the SSR when/how to apply that power. The on/off cycling of the SSR generates heat (SSR gets warm) and the heat sink is connected to the SSR to disperse the heat (consider them cooling fins) preferable outside of an enclosure.

3: I have seen my options for solid state relays (25A, 40A) but don’t know how to calculate how much amperage my system would be using.

A 4,500 watt element connected to 240v will pull 18.75 amps, a 25A would be fine. A 5,500 watt element connected to 240v will pull 23 amps, a 25A might work but a 40A would be a much better choice. Keep in mind the 80% rule (actual draw of the circuit should be 80% of the circuit rating [wires, breaker]).

4: My Ranco can use multiple temperature probes connected in series and it will read the average temp of all of them. I have not seen a PID that states this as a feature. Does any one know if any/all PIDs are capable of this?

No...I'm pretty sure a Ranco can only control 120v components. You don't really need multiple temp probes or average temps, one would be fine. Besides, do you really want to be calibrating multiple probes? IMHO, get a PID with SSR & heat sink and use the Ranco on a fridge to control fermentation temps.

 

[homebeerbrewer]

Does this mean that I can be plugged into a 120v outlet, use a 12v PID (120-12=108), incorperate a 40A SSR, and be able to ran my element at 4320 watts (108*40=4320)? Is that how this works?

Think of it this way: the relay has two sides. One is the low voltage side, the other is high voltage. The low voltage side works with your PID. The high voltage side works with the heating element. The PID sends low voltage electricity to the relay, the relay activates, flipping the switch to turn on or off the high voltage side.

Did that make more sense?

 

[TAD]

Yes, very helpful.
I will try and keep posting with my decisions on the setup.