List of PJ Electrical Diagrams

[GotPushrods]

(edit) If the pump fuse blows the element could still be fired... Thoughts/solutions?

You could power the wall wart after the 4A fuse. You'd lose Uno power, but it could be better than a burned mash. Of course you'd need the pump on the power the Uno. Ditching the series switches for a relay or contactor would probably be best in this situation. Maybe someone will have a clever solution to this

 

[nwestby]

Question. How does the coil rating of a contactor work? I see PJs diagrams often call for a 240v 30A contactor with 120v coil. What if the coil was rated at 240v?

 

[GotPushrods]

Question. How does the coil rating of a contactor work? I see PJs diagrams often call for a 240v 30A contactor with 120v coil. What if the coil was rated at 240v?

This refers to the voltage required to operate the coil and close the contacts of the contactor. Instead of the coil getting L1 and neutral, it gets L1 and L2. Either one (or both) can be routed through a switch.

 

[thekraken]

What if I just used one main fuse at at the mains entrance in the control box like this updated drawing. IF this would be OKAY what size fuse would I need?

I was planning on wiring this thing up for 20 amps while it should only require 15, a little shopping around revealed that 20A duplex light switches aint cheap. Would 15A be sufficient?

 

[BadNewsBrewery]

The fuse as you show it there would need to be sized for the pump and the element - the element draws a lot more, so it'd be a large (15+a) fuse. So it's not really protecting the pump, which is only supposed to draw 1.4... Plus you'd technically want to run larger sized wiring to keep it matched with the fuses.

 

[thekraken]

Okay, what about this revision:

 

[BadNewsBrewery]

You have your element running through the 4A fast blow - not good.

Suggest you start your own thread instead of hijacking this thread for your personal project.

 

[Dubchedford]

Quick question. I'm planning a build based off the diagram below. This may have been already answered, but are these just standard 40A SSRs shown in this diagram? I noticed they look slightly different than the SSRs in the other diagrams.

 

[thekraken]

You have your element running through the 4A fast blow - not good.

I tried to route the element just through the contactor, and just the pump through the fuse in such a way that if the fuse blows the contactor breaks the element connection. Did I mess this up?

Suggest you start your own thread instead of hijacking this thread for your personal project.

Sorry. my drawings are based on PJ's diagrams, I figured this was the best place to ask questions. Anyone who needs a schem for a 120v single element single pump RIMS system doesn't quite have an ideal example at the start of this thread, I figured this would contribute to the discussion. (Arduino can be directly swapped for off the shelf PID)

 

[BigFloppy]

Quick question. I'm planning a build based off the diagram below. This may have been already answered, but are these just standard 40A SSRs shown in this diagram? I noticed they look slightly different than the SSRs in the other diagrams.

yes, they are

 

[P-J]

Quick question. I'm planning a build based off the diagram below. This may have been already answered, but are these just standard 40A SSRs shown in this diagram? I noticed they look slightly different than the SSRs in the other diagrams.

The SSRs are the same. I used that SSR layout as they are narrow & fit on the page. The other illustrations I use are much wider and would occupy too much space in that particular diagram.

Hope that makes sense.

P-J

 

[Dubchedford]

The SSRs are the same. I used that SSR layout as they are narrow & fit on the page. The other illustrations I use are much wider and would occupy too much space in that particular diagram.

Hope that makes sense.

P-J

Perfect! I figured they were, but I just wanted to make sure. Thanks again for all of the help P-J

 

[BadNewsBrewery]

I tried to route the element just through the contactor, and just the pump through the fuse in such a way that if the fuse blows the contactor breaks the element connection. Did I mess this up?

You're right - I looked at it wrong. The coil is fed off the 4a fuse, but the element itself isn't. You're spot on.

Sorry. my drawings are based on PJ's diagrams, I figured this was the best place to ask questions. Anyone who needs a schem for a 120v single element single pump RIMS system doesn't quite have an ideal example at the start of this thread, I figured this would contribute to the discussion. (Arduino can be directly swapped for off the shelf PID)

No worries - I just thought you were getting further into development. I think at the beginning, this was supposed to be a repository of diagrams that had been looked at and validated, so someone could come in here and find a diagram that is known to work. When the thread (d)evolves into diagram development, the 'proven to work' portion is lost. Someone coming in here to find a usable diagram will get lost amongst the multiple itterations of people trying to develop the diagram. Not only you, but plenty of folks. So I was thinking maybe you'd get better input and feedback from folks that have abandoned this thread, but are still willing to help.

Of course, you do as you wish - I'm not the internet police, and I'll still try and help as best I can.

 

[theck]

I'd like to have a light indicator I'm assuming the 30A 5500 Single Element PID diagram you can just add the light in the same way as the 4500 Single Element no pump PID diagram, correct?

Also can I use something like these rockers instead of the toggle:
http://www.ebay.com/itm/USA-Red-Light-On-off-Rocker-Switch-250V-15-AMP-125-20A-/141219601284

 

[theck]

Also, the diagrams don't show a heat sink but I see a lot of builds have them, are they required or suggested or ?? Can you tell I'm a newbee?

 

[kal]

A heat sink is required on any and all SSRs.

Some people put them inside their (sealed) control panels. I prefer to have them outside so that they can release the heat and not cook everything in the panel, shortening the lifespan of not only the SSR, but all of the other electronic devices that use parts that are prone to failure due to heat (most notably electrolytic capacitors).

Kal

 

[theck]

A heat sink is required on any and all SSRs.

Some people put them inside their (sealed) control panels. I prefer to have them outside so that they can release the heat and not cook everything in the panel, shortening the lifespan of not only the SSR, but all of the other electronic devices that use parts that are prone to failure due to heat (most notably electrolytic capacitors).

Kal

Thanks, can I mount it to the back or top of the box then cut a hole big enough for the ssr to stick though and connect it that way? I'm assuming a bigger heat sink is better?

 

[kal]

Thanks, can I mount it to the back or top of the box then cut a hole big enough for the ssr to stick though and connect it that way? I'm assuming a bigger heat sink is better?

Correct on all accounts.

I went with an oversized heat sink myself. Pictures:

More details/steps here.

Kal

 

[theck]

Cool thanks for the info... I plan on doing a super simple build (one 5500, pid, no pumps, no extras) so that might be way way overkill?

 

[kal]

Cool thanks for the info... I plan on doing a super simple build (one 5500, pid, no pumps, no extras) so that might be way way overkill?

For a single SSR, yes. I would still recommend putting the heat sink outside and using a heat sink meant for a larger SSR than you need. There are no "rules" as to heat sink size so many of the bargain sellers are supplying undersized heat sinks with their SSRs and expecting you to use a fan.

Kal

 

[theck]

For a single SSR, yes. I would still recommend putting the heat sink outside and using a heat sink meant for a larger SSR than you need. There are no "rules" as to heat sink size so many of the bargain sellers are supplying undersized heat sinks with their SSRs and expecting you to use a fan.

Kal

I have an old computer cpu, think 4", fan that I might hook up as well since it just collects dust. Would I need a 220 to 12v transformer to hook that up? Figured I'd throw that in there if I ever needed to upgrade.

 

[kal]

I have an old computer cpu, think 4", fan that I might hook up as well since it just collects dust. Would I need a 220 to 12v transformer to hook that up?

Depends on what the fan requires. Check the fan.

I'm not a fan of fans (pardon the pun). I prefer convection cooling. Fans can fail and are not weather/waterproof.

Kal

 

[theck]

Ah maybe I won't bother then... one last question, for now . I am checking out some builds and I see terminal bus strips, I think? I'd need 4 of those at the start of the wiring; GND, Neutral, Line 1 and Line 2, correct? I'm confused though on this:

and why the wires are looped... is that done to allow more than 2 connections?

 

[schematix]

Whew. Just got done reading all 57 pages of this thread. A very good read indeed!

One question that remained after reading all of this is what is the purpose of the contactors after the SSR, but before the heating elements? Are these strictly necessary or just recommended? If so, why? The SSR manufacturers don't have these in their recommended schematics.

Thanks!

 

[thekraken]

They are a safety feature. The contactors are actuated by switches on the control panel, not the ssr. No matter what the ssr wants to do it can only do what you say it can do. It forces you to stop and think 'okay, are we ready to go? is the pump primed? is the element submerged?' etc. Also, if you need to you can go the control panel and physically interrupt the current to the elements.

You could build your control panel without them but it doesn't seem like a good idea to me, wouldn't be much of a 'control' panel.

 

[Fatman_Brew]

Ah maybe I won't bother then... one last question, for now . I am checking out some builds and I see terminal bus strips, I think? I'd need 4 of those at the start of the wiring; GND, Neutral, Line 1 and Line 2, correct? ...(picture deleted)..

and why the wires are looped... is that done to allow more than 2 connections?

That is a barrier terminal strip. Each strip is isolated from the next. The jumpers are used to provide a conductive path to the next strip. Typical ratings are 15amp, with 20amp and 30amp being available as well. There are other ways to do the same thing, depending on how many branch feeds are needed and wire gauge.

 

[theck]

That is a barrier terminal strip. Each strip is isolated from the next. The jumpers are used to provide a conductive path to the next strip. Typical ratings are 15amp, with 20amp being available as well. There are other ways to do the same thing, depending on how many branch feeds are needed and wire gauge.

I think he was using 30a, that's what would be required correct? Thanks!

 

[Fatman_Brew]

I wouldn't use a 15/20 amp terminal strip to feed a 30amp circuit when a simple wire nut or splice would work. Make sure of amp ratings for any connections.

 

[mavrick1903]

This should be a sticky!

 

[schematix]

They are a safety feature. The contactors are actuated by switches on the control panel, not the ssr. No matter what the ssr wants to do it can only do what you say it can do. It forces you to stop and think 'okay, are we ready to go? is the pump primed? is the element submerged?' etc. Also, if you need to you can go the control panel and physically interrupt the current to the elements.

You could build your control panel without them but it doesn't seem like a good idea to me, wouldn't be much of a 'control' panel.

I've seen a number of control panels for other heating applications in industry using SSRs to throttle power delivery and I never saw contactors used on the load side. They were always used to disconnect groups of heaters on the line side. For example, there'd be a branch circuit with a 100A OCPD, followed by a 100A contactor, then split into individual OCPD for each heater, and then finally to the SSRs. The heaters would connect directly to the SSR outputs. The contactor would typically be tied into the emergency stop circuit, sometimes with an additional permissive from the PLC.

I always liked it tied into the PLC because if any one zone exceeded a threshold, i'd shut off all heating. This prevented a runaway in the event that a temp probe was wired to the wrong zone, or a faulty temp probe in general, because otherwise the PID would keep the heater on (and at 100% since the integral would wind up).

There are lots of ways to skin this cat and if someone wants the additional level os safety I don't see that it hurts, I just wanted to make sure I wasn't overlooking a function of it beyond it being an additional permissive.