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Old 04-25-2011, 01:42 PM   #21
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Originally Posted by TonySwank View Post
I am in the middle of designing and building and electric brewery and was wondering if it would be possible to controlled the heating elements manually at either the breaker or my installing an inline switch.
Do not use a circuit breaker in your panel as a switch. That's not the purpose of a breaker.

Same thing with plugging/unplugging high current heating elements from the wall to turn them on/off. That's not safe. A switch of some sort that is meant to be switched should be used. A wall outlet/socket combination is not a switch.

In the end, anyone can do anything they like of course. Just pointing out what's safe/normal.

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Old 04-25-2011, 02:42 PM   #22
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Originally Posted by kal View Post
Do not use a circuit breaker in your panel as a switch. That's not the purpose of a breaker.

Same thing with plugging/unplugging high current heating elements from the wall to turn them on/off. That's not safe. A switch of some sort that is meant to be switched should be used. A wall outlet/socket combination is not a switch.

In the end, anyone can do anything they like of course. Just pointing out what's safe/normal.

Kal
Hi Kal - I agree with you, just being devil's advocate here. If you used the breaker as a switch, is it truly unsafe? I mean as long as the box is closed up, I can't see how this would be unsafe. especially since the user would likely only be brewing once a week at most.

Not saying this is correct usage for a circuit breaker, but not sure it would technically be unsafe to do.


TonySwank - why not use a contactor with a switch to control your heating elements? Pretty cheap addition. That is how I put mine together. The PID can't activate the element unless I manually give the element power through my switch to the contactor.


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Old 04-25-2011, 03:34 PM   #23
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Hi Kal - I agree with you, just being devil's advocate here. If you used the breaker as a switch, is it truly unsafe? I mean as long as the box is closed up, I can't see how this would be unsafe. especially since the user would likely only be brewing once a week at most.

Not saying this is correct usage for a circuit breaker, but not sure it would technically be unsafe to do.
Sorry, unsafe is probably the wrong choice of words in the case of using a breaker as a switch.

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Old 04-25-2011, 03:40 PM   #24
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Keep in mind: The "80% rule" does NOT apply to a single outlet circuit.
Also, the "rule" applies to the home designer and/or the electrician installing the electrical circuits. It does not apply to the home owner.

A 4500W element in your HLT and a 5500W element in the BOIL would solve your power concerns for back to back brews.
Thanks for the clarification about the 80% rule, I misunderstood it before. Now to decide if back to back batches is worth another $150 or so in PID/SSR/Heat Sink/misc. This scope/budget creep came up quickly.

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Do not use a circuit breaker in your panel as a switch. That's not the purpose of a breaker.

Same thing with plugging/unplugging high current heating elements from the wall to turn them on/off. That's not safe. A switch of some sort that is meant to be switched should be used. A wall outlet/socket combination is not a switch.
Kai, I completely agree and I am definitely beyond using the breaker as a switch, it is a less than ideal situation at best. The question was more out of curiosity, but since we're dealing with electricity there should be no confusion out there.

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TonySwank - why not use a contactor with a switch to control your heating elements? Pretty cheap addition. That is how I put mine together. The PID can't activate the element unless I manually give the element power through my switch to the contactor.
Just a quick clarification about contactors, once power is cut to an element the contactor will open and a the connected switch will need to be activated to power the element again. I'm assuming the purpose of these are typically to ensure the element is not hot when power to the control panel is activated. What type of switches/buttons are commonly used with contactors? Is the general consensus that contactors are a better solution than using a double pole double throw switch between the elements?
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Old 04-25-2011, 03:41 PM   #25
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Well it certainly isn't a "normal" use for a circuit breaker. Ok no more semantics crap from me - the lowly electrical newb. Best,

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Old 04-25-2011, 04:00 PM   #26
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Just a quick clarification about contactors, once power is cut to an element the contactor will open and a the connected switch will need to be activated to power the element again.
?
Correct - No power to contactor (switch off position) = contactor open and no power to element.

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I'm assuming the purpose of these are typically to ensure the element is not hot when power to the control panel is activated.
That was my purpose and I have two outlets on my box, so I went with an On-Off-On Switch to toggle between each outlet and off (one contactor for each outlet). Purpose being:

1. Two elements can't be on at the same time;
2. in the off position, there is no way for the PID to turn the elements on (your point above).

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What type of switches/buttons are commonly used with contactors?
I used a basic 10amp on-off-on (SPDT) switch from Home depot
EDIT - I put the switch on a line that had a 1amp FB fuse, so you could in theory never get more that 1amp from the line to the switch.


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Is the general consensus that contactors are a better solution than using a double pole double throw switch between the elements?
I think this is a builder's preference - but I like the idea of never touching something that has 240v running through it (with potentially wet hands). The contactors are powered by 120v.
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Old 04-25-2011, 04:07 PM   #27
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I think this is a builder's preference - but I like the idea of never touching something that has 240v running through it (with potentially wet hands). The contactors are powered by 120v.
Agreed.

Generally speaking, if you look at how control panels and such are designed, you never put high current/voltage items on the door or front of the panel. You put lower power "control" stuff on the panel and the heavy stuff is permanently bolted to the backplane of the panel. One big reason for doing this is that the high current wires used by the big power stuff is stiff. You want to have it installed such that it doesn't move. So all wire that gets bent/pulled/pushed as the swinging door gets opened/closed is lower amperage wiring. This is done for safety and ease of installation/use.

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Old 04-27-2011, 11:18 PM   #28
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Alright, thanks so much for the help everyone. I am planning on going the route similar to what I initially posted, using the contactors and only having one element active at a time. I will most likely use a 4500 watt element in the HLT so when I feel like adding another PID/SSR/Heat Sink I will be able to run both elements at the same time for back to back batches.



My biggest question now is getting power to the control panel. I have a 50 amp plug (14-50R) and will be using a 4 wire range power cord like this one.



The issue I am having is finding 50 amp plugs and receptacles, the few that I have found don't look like they would work well. Right now it looks like my options are to either hardwire the power cord to the control panel, which is what I am leaning towards, or downgrade to using 30 amp plugs. The 30 amp plugs should not be an issue but it would be nice to have the full 50 amps available in the future. I saw that Walker hardwired his and as long as the cord is attached to the external box well the internal components shouldn't be stressed.

I will be using a DIN Power Rail for power distribution. Never used one before but looks like it should be a nice space saver. Any tricks?

For the pumps I will be using a duplex outlet with each outlet wired to the an individual switch, similar to what PJ mentioned here. Never wired up a duplex outlet individually but don't see any issues.

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Welcome.

You might consider using a duplex outlet. It might make your life a little easier.



The arrows point to a small break away tab. Just snap off the one on the left side (brass terminal screws). This way you will eliminate some wiring complexity as the neutral and ground will be common for both outlets.

You would only need to cut one hole in the box as well.
Can't think of anything else right now. Any comments are welcome. You guys have been a huge help and I am really excited to get the project going.
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Old 04-28-2011, 12:18 AM   #29
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Agreed.

Generally speaking, if you look at how control panels and such are designed, you never put high current/voltage items on the door or front of the panel. You put lower power "control" stuff on the panel and the heavy stuff is permanently bolted to the backplane of the panel. One big reason for doing this is that the high current wires used by the big power stuff is stiff. You want to have it installed such that it doesn't move. So all wire that gets bent/pulled/pushed as the swinging door gets opened/closed is lower amperage wiring. This is done for safety and ease of installation/use.

Kal
I never thought of this... I will work this into my future build. Thanks for helping to keep my hairs straight.
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Old 04-28-2011, 02:05 AM   #30
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Upon thinking more about this set up, I have a question...

Is the contactor simply insurance to prevent the PID from dry heating the element? If so, wouldn't a $1 switch for the PID power be a cheaper solution than the contactor? Am I missing a benefit of the contactor?

I am assuming that if the PID is powered off the SSR is open (off)... Is that a correct assumption?



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