31 replies to this topic

[zymot]

you're right ... thanks! I was attempting to make everything fit and must of missed that. v. 2.0.2

The PID/Solenoid/Switch still section is not correct. If you build it as shown, when the PID tries to energize the solenoid, it will short out your 120 VAC trunk lines.When I can get to a computer where I can draw a what I am tlaking about, I will show you what I mean.zymot

[Stout_fan]

I don't think this was mentioned. But other than the mains disconnect, you only need to switch one leg of the loads.SPST switches are a lot cheaper than DPST ones.

[zymot]

I don't think this was mentioned. But other than the mains disconnect, you only need to switch one leg of the loads.SPST switches are a lot cheaper than DPST ones.

Good point. the SPST switches are cheaper. The DPST have a hypothetical added safety margin of not putting 120 VAC down all around the rig, except when the device is energized.

The PID/Solenoid/Switch still section is not correct. If you build it as shown, when the PID tries to energize the solenoid, it will short out your 120 VAC trunk lines.When I can get to a computer where I can draw a what I am tlaking about, I will show you what I mean.zymot

Here is a solution to the problem I mentioned above.This assumes that the PID is configured such that when the temp condition is met, the PID switches the HOT leg of your trunk to terminal 3 thru 5. In other words, I assume your wiring of terminals 1-5 is correct and safe.

Edited by zymot, 25 May 2010 - 12:05 PM.

[EWW]

Good point. the SPST switches are cheaper. The DPST have a hypothetical added safety margin of not putting 120 VAC down all around the rig, except when the device is energized. Here is a solution to the problem I mentioned above.This assumes that the PID is configured such that when the temp condition is met, the PID switches the HOT leg of your trunk to terminal 3 thru 5. In other words, I assume your wiring of terminals 1-5 is correct and safe.

Zymot you deserve a few bottles of the first batch I do on this when I finish it...big thanks! My wiring on the PID is based off how I saw it wired elsewhere on the web - I plan to double check that when I get the device and manual in the mail.The only other thing I haven't figured out is how to effectively ground to the GFCI. For some reason I just can't visualize this without the pieces in front of me ... Any thoughts?

[EWW]

Good point. the SPST switches are cheaper. The DPST have a hypothetical added safety margin of not putting 120 VAC down all around the rig, except when the device is energized. Here is a solution to the problem I mentioned above.This assumes that the PID is configured such that when the temp condition is met, the PID switches the HOT leg of your trunk to terminal 3 thru 5. In other words, I assume your wiring of terminals 1-5 is correct and safe.

Zymot you deserve a few bottles of the first batch I do on this when I finish it...big thanks! My wiring on the PID is based off how I saw it wired elsewhere on the web - I plan to double check that when I get the device and manual in the mail.The only other thing I haven't figured out is how to effectively ground to the GFCI. For some reason I just can't visualize this without the pieces in front of me ... Any thoughts?

[zymot]

Zymot you deserve a few bottles of the first batch I do on this when I finish it...big thanks! My wiring on the PID is based off how I saw it wired elsewhere on the web - I plan to double check that when I get the device and manual in the mail.

Homebrewers help other homebrewers. It is the most altrusistic hobby I know of.

The only other thing I haven't figured out is how to effectively ground to the GFCI. For some reason I just can't visualize this without the pieces in front of me ... Any thoughts?

A simplified description.The job of a GFI is to measure the current going out of the + leg and compare it to the amount of current that gets returned on the N leg. If more current goes out than comes back, the GFI assumes the missing current is going through your body and shuts everything down.So if you are going to use the GFI, leaving the ground open will give you the safety factor of a GFI.If your pump, switches, solenoids and transformers have any current leakage, it will trip the GFI and could become quite annoying.If you want to, you could ground the frame of your sculpture frame & brew pots. See if the other solenoids, pump etc cause the GFI to trip.zymot

[Stout_fan]

... The DPST have a hypothetical added safety margin of not putting 120 VAC down all around the rig, except when the device is energized. ...

That's why you put the switch on the hot side and not the neutral.And of course, that presumes your 120v outlet has been wired properly.And there is not too much neutral lift.

[zymot]

That's why you put the switch on the hot side and not the neutral.And of course, that presumes your 120v outlet has been wired properly.And there is not too much neutral lift.

I guess my qualifier of hypothetical wasn't good enough for you? (J/K)When you are talking an environment that will have a large quantity of liquids and manual switches and PID switches opening and closing automatically and metal frames and stuff and sparks and solenoids, switching both legs of the AC isn't a bad idea. Other than your previously noted financial impacts.zymot

[EWW]

Both good points on the switches ... We're not talking about huge money here. Sure the DPST are twice as much, but they are still under $5. SPST are around $2. With that being said, I may just go with SPST mini toggles for everything except the main power switch to help keep the size of my control panel more compact.

[3rd party JKor]

MaybeI'm misunderstanding zymots diagram, or the terminal functions, but I don't think the drawing in zymots post will work. My uinderstanding of the controller is that it has an internal relay that switches the hot leg of the 120VAC circuit. You should have the hot leg going into the controller on terminal 5 and going out on terminal 4. I don't understand why terminal 3 is jumped to terminal 4 unless terminal 3 is at line voltage, then my point is moot. Although, if that is the case, I don't see the point of the SPST switch between the hot leg going into terminal 1 and hot leg coming off terminal 5, unless it is a manual bypass switch?

[zymot]

MaybeI'm misunderstanding zymots diagram, or the terminal functions, but I don't think the drawing in zymots post will work. My uinderstanding of the controller is that it has an internal relay that switches the hot leg of the 120VAC circuit. You should have the hot leg going into the controller on terminal 5 and going out on terminal 4. I don't understand why terminal 3 is jumped to terminal 4 unless terminal 3 is at line voltage, then my point is moot. Although, if that is the case, I don't see the point of the SPST switch between the hot leg going into terminal 1 and hot leg coming off terminal 5, unless it is a manual bypass switch?

You make a good point. In my comments that came with my diagram, I had the caveat of:

This assumes that the PID is configured such that when the temp condition is met, the PID switches the HOT leg of your trunk to terminal 3 thru 5. In other words, I assume your wiring of terminals 1-5 is correct and safe.

The PID terminals 1 thru 5 in my drawing are exactly as EWW has shown them in every one of his diagrams. (Term #1 = Hot, Term #2 = Neutral, Term 3 thru 5 bussed? = switched hot output)I did not dig through an owner's manual to confirm this portion of the design.zymot

[Stout_fan]

I guess my qualifier of hypothetical wasn't good enough for you? (J/K) ...zymot

Well, only hypothetically.