HERMS Electronics?

TAD · 07-26-2009, 09:36 PM

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 · 07-27-2009, 02:41 AM

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 · 07-27-2009, 12:22 PM

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** · 07-27-2009, 12:36 PM

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 · 07-27-2009, 12:59 PM

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.

Quote:

Originally Posted by 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,

**Bobby_M** · 07-27-2009, 02:19 PM

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 · 07-27-2009, 02:20 PM

Quote:

Originally Posted by 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?

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** · 07-27-2009, 02:26 PM

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 · 07-27-2009, 02:30 PM

Quote:

Originally Posted by 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.

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

ClaudiusB · 07-27-2009, 03:07 PM

Quote:

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