How would you build a 240v controller that can power a 9kw element?

[bcook608]

So if you've seen my other thread on my controller build, you know it's not going as well as I thought it would. So I figured I'd ask the masses. How would you build a 9kw controller?

It doesn't need to be super fancy at this point, I just want something that will work. I'm mostly looking for wiring diagrams for a 3-wire system as I'm stuck with the outlet I have available.

I have a unique situation where I have to run an extension cord from my kitchen (which has a 10-50p 3 prong outlet) to my master bedroom to still. I have a 50 foot 6/3 extension cord that I've cut a bit shorter, using the extra length to add pigtail outlets to my box. I can't change the electrical outlet in the kitchen so I'm stuck with 3 wire...

The outlet I'm using is on a 50a range circuit.

Right now I have the following parts available:

Large junction box
Digital ammeter/volt meter
Auber DSPR1 controller
80a SSR and heatsink
240v electromagnetic relay
30a double pole switch

Sorry for an additional topic about the same issue, but I need a fresh start.

[tiramisu]

Why not just use 2 4500 or 5kw elements?

[bcook608]

Why not just use 2 4500 or 5kw elements?

Only have one circuit available and I don't want to modify my Boiler again.

How would you wire it if you did 2 elements?

[Salt Must Flow]

Why not just use 2 4500 or 5kw elements?

Only have one circuit available and I don't want to modify my Boiler again.

How would you wire it if you did 2 elements?

I would make room by replacing some breakers with some of this style of breaker. Free up some space for two 240V ripple ULWD elements.

[shadylane]

How would you wire it if you did 2 elements?

I use two 4500w heaters in a 18ish gallon boiler.
One element is variable from 0-100%
The other element uses a simple switch so it can be 25% or 100%
This way I only need one controller.

[shadylane]

Why not just use 2 4500 or 5kw elements?

Only have one circuit available and I don't want to modify my Boiler again.

Are you planning on using a single 9Kw element?
How big is your boiler?

[Yummyrum]

You can run up to 6 SSRs off the DSPR1 . So you could easily use another SSR , one for each element .

[NZChris]

If your element consists of several elements that can be individually wired there are lots of options, but you haven't told us what it is.

[ecir54]

get rid of the relay and just wire it like the manual says, kiss approach.

https://www.auberins.com/index.php?main ... cts_id=444

[Salt Must Flow]

get rid of the relay and just wire it like the manual says, kiss approach.

https://www.auberins.com/index.php?main ... cts_id=444

What do you mean, "get rid of the relay"? This controller is intended to be used with a SSR and a heatsink.

[shadylane]

Output: 12VDC, 80 mA

That's not going to power much of a heater.

[Yummyrum]

Thinking he means the electromechanical Relay ( Contactor)
IMO , you should keep it . With a big Red “I stop button” controlling it .

[ecir54]

example 1

https://www.auberins.com/images/Manual/ ... ual_V1.pdf

[Yummyrum]

example 1

https://www.auberins.com/images/Manual/ ... ual_V1.pdf

For sure eric , the basic setup does not need to be complicated .

But 9kw is a lot of power I’d want to be able to kill in an instant if needed . SSR’s can fail short circuit . So another means of shutting off power is important .

[ecir54]

Wouldn't the switch or unplugging cord serve the same purpose as a button.

Would do as already stated and do what's needed to use two elements.

[ecir54]

another option for protection would to add a fused disconnect at end of his cord and hang it next to his operation and use fast acting fuses, fuses would blow as soon as a short would be detected.

[Yummyrum]

Wouldn't the switch or unplugging cord serve the same purpose as a button.

Absolutely eric , a switch would work if you got one handy . Just big arse switches are expensive . … well they are here .

The advantage ( as I see it ) of using a contactor with a I-Stop switch is that its obvious to anyone that it’s a kill switch ….. imagine mum walks in and sees Dad collapsed and freaks out . …. Hit the kill switch .

Also , extra safety circuits can be added to it such as coolant/pump failure detection and over temp sensors if required .

Not trying to argue the point with you eric , just a discussion …. and believe me, I’m all for KISS .

[quadra]

I am not.. for keeping it simple... I want it to have layers of stupid proof to protect myself. I want a GFCI circuit.. and a proper modern 4 wire hookup, so that I can tap the ground and neutral. Why? Because a short to neutral can keep conducting below the breaker trip level ... we are dealing with current and voltage that will stop you dead. The reason all the modern 240v plugs have the 4th pin is to ensure an Earth ground... if shit goes wrong that Earth ground will allow a massive current outrush that will cause a quick trip of the breaker. The way this was wired before you could grab the kettle and touch the sink and ( potentially )± only conduct 10 or15 amps of 240v... not enough to trip the breaker if the kettle was hot and pulling low current... however you would become a resistance device.

The diagrams on the Auber site are all you need for a basic controller, I personally would use the electromechanical relay with a conspicuous dedicated kill switch to disconnect both legs of the heating element if you need an E-stop. The link previously posted to the Electric Brewery site has a lot of solid information that will help you understand power management, but if you are still only finding 120v to your element you have not wired things correctly and/or have a leg of your 240 that is not where you think it is. You do not need someone to draw you a picture, you need to understand this the way you understand why you do not drink water from a pressure washer hose.

[Bradster68]

So if you've seen my other thread on my controller build, you know it's not going as well as I thought it would. So I figured I'd ask the masses. How would you build a 9kw controller?

It doesn't need to be super fancy at this point, I just want something that will work. I'm mostly looking for wiring diagrams for a 3-wire system as I'm stuck with the outlet I have available.

I have a unique situation where I have to run an extension cord from my kitchen (which has a 10-50p 3 prong outlet) to my master bedroom to still. I have a 50 foot 6/3 extension cord that I've cut a bit shorter, using the extra length to add pigtail outlets to my box. I can't change the electrical outlet in the kitchen so I'm stuck with 3 wire...

The outlet I'm using is on a 50a range circuit.

Right now I have the following parts available:

Large junction box
Digital ammeter/volt meter
Auber DSPR1 controller
80a SSR and heatsink
240v electromagnetic relay
30a double pole switch

Sorry for an additional topic about the same issue, but I need a fresh start.

Post a pic of the stove outlet please, a 10 50 plug uses 2 hot wires and a ground for saftey. If your running a 50 amp cookstove on that circuit it'll more than power your element

[TwoSheds]

Hey BCook,

Not sure I follow the meandering responses above, but figured I'd share a couple things I've learned from putting together my controller (and some other 240v circuits.)

The 10-50p has two hots and a neutral and should work for your 240v element.

watts/volts = amps

9,000w/240v=37.5a

That is a REALLY good place to be on a 50a circuit. Electric code requires an amount of overhead for resistive heaters. I don't remember exactly how much, but you're at 75% of what the circuit is rated for, which should be pretty safe.

Your SSR has plenty of capacity and the DSPR1 should do the trick.

What's the "240v electromagnetic relay"? If it's something like a contactor, you want that! Make sure it can take the capacity you're throwing at it.

What I figured out, after cooking a 30a switch with considerably less than 30a of juice, is to run all your heavy current into the box, both legs through the contactor, one leg through the SSR, then out to the heater. All that needs to be heavy gauge wire to carry all the current to your heater.

Everything else should be able to run on light hook-up wire. I run two switches but with just one I would wire it to your contactor and wire the DSPR1 right to the incoming current. That way as long as your system is plugged in the controller will be on. The switch will basically be a kill to the output which means you can shut off your heater while you program the controller.

I like having an indicator on the ouput so I can see what the controller is doing, but that's totally optional. Auber sells some line-voltage LEDs.

Hope that helps. PM me if you want to see my messy sketch.

And stay safe! You're playing with some dangerous voltage there...

TwoSheds

[Ben]

I would run all power in through a switched contactor. That way no matter what the box is powering (element, pumps, fans, etc) one stop button shuts it all down, instantly.

I would also run 2 elements, both controlled by a DSPR. The DSPR makes the heat up cycle a lot less of a stressful task, you can pretty much eliminate the possibility of a boil over (always seems to happen in the 2 seconds you turn your back). Running somewhere like a bedroom where you likely don't have floor drains which makes this even more desirable. Also dead simple to make adjustments and repeatability is simple. Indicator light shows you if it is firing the relay. This also gives you a boiler control for future projects, makes all grain a lot easier if you ever go that route.

I would run one indicator (22mm pilot lights are common) that shows your 240v power is on. That will make diagnosis easier down the road if there is trouble and gives you an added layer of safety.

I would run one indicator that shows your 120v power is on, if you are going to use 120v from it.

Twist lock inlet and outlet connectors.

RTD connector of your choice, I use XLR.

Keep the box small so its easy to move around.

Overkill the heat sinks so you don't have to have annoying little fans running in your ear all the time.

My compact still controller:

Oh, and paint it and photograph it well, so you can be proud when you post pics

[bcook608]

Why not just use 2 4500 or 5kw elements?

Only have one circuit available and I don't want to modify my Boiler again.

Are you planning on using a single 9Kw element?
How big is your boiler?

I have a single 9kw element. It's going in a 26 gallon boiler.

[bcook608]

So if you've seen my other thread on my controller build, you know it's not going as well as I thought it would. So I figured I'd ask the masses. How would you build a 9kw controller?

It doesn't need to be super fancy at this point, I just want something that will work. I'm mostly looking for wiring diagrams for a 3-wire system as I'm stuck with the outlet I have available.

I have a unique situation where I have to run an extension cord from my kitchen (which has a 10-50p 3 prong outlet) to my master bedroom to still. I have a 50 foot 6/3 extension cord that I've cut a bit shorter, using the extra length to add pigtail outlets to my box. I can't change the electrical outlet in the kitchen so I'm stuck with 3 wire...

The outlet I'm using is on a 50a range circuit.

Right now I have the following parts available:

Large junction box
Digital ammeter/volt meter
Auber DSPR1 controller
80a SSR and heatsink
240v electromagnetic relay
30a double pole switch

Sorry for an additional topic about the same issue, but I need a fresh start.

Post a pic of the stove outlet please, a 10 50 plug uses 2 hot wires and a ground for saftey. If your running a 50 amp cookstove on that circuit it'll more than power your element

[bcook608]

Hey BCook,

Not sure I follow the meandering responses above, but figured I'd share a couple things I've learned from putting together my controller (and some other 240v circuits.)

The 10-50p has two hots and a neutral and should work for your 240v element.

watts/volts = amps

9,000w/240v=37.5a

That is a REALLY good place to be on a 50a circuit. Electric code requires an amount of overhead for resistive heaters. I don't remember exactly how much, but you're at 75% of what the circuit is rated for, which should be pretty safe.

Your SSR has plenty of capacity and the DSPR1 should do the trick.

What's the "240v electromagnetic relay"? If it's something like a contactor, you want that! Make sure it can take the capacity you're throwing at it.

What I figured out, after cooking a 30a switch with considerably less than 30a of juice, is to run all your heavy current into the box, both legs through the contactor, one leg through the SSR, then out to the heater. All that needs to be heavy gauge wire to carry all the current to your heater.

Everything else should be able to run on light hook-up wire. I run two switches but with just one I would wire it to your contactor and wire the DSPR1 right to the incoming current. That way as long as your system is plugged in the controller will be on. The switch will basically be a kill to the output which means you can shut off your heater while you program the controller.

I like having an indicator on the ouput so I can see what the controller is doing, but that's totally optional. Auber sells some line-voltage LEDs.

Hope that helps. PM me if you want to see my messy sketch.

And stay safe! You're playing with some dangerous voltage there...

TwoSheds

Yes, it's an electromagnetic contactor. The issue I'm running into is that it seems only 120v is making it through to the element. That, or I am having issues with my ammeter/volt meter and it isn't reading correctly. I'm going to have to pick up a multimeter and see if I can identify where the issue is. Right now when I crank it to full power, it's only reading 4500w +/- a few watts

[bcook608]

Thinking he means the electromechanical Relay ( Contactor)
IMO , you should keep it . With a big Red “I stop button” controlling it .

This is my relay. It's an electromagnetic switch and I have my output wired to the "normally open" terminals meaning that if there is a power issue in the switch, it'll fail open (off).

[shadylane]

The issue I'm running into is that it seems only 120v is making it through to the element. That, or I am having issues with my ammeter/volt meter and it isn't reading correctly. I'm going to have to pick up a multimeter and see if I can identify where the issue is. Right now when I crank it to full power, it's only reading 4500w +/- a few watts

If a 9Kw 240v heater is running on 120v the watts would be 1/4 of it's rated power. 2250W
Is the 9Kw heater rated for 380v


Have you got a part# for the heater?

[bcook608]

The issue I'm running into is that it seems only 120v is making it through to the element. That, or I am having issues with my ammeter/volt meter and it isn't reading correctly. I'm going to have to pick up a multimeter and see if I can identify where the issue is. Right now when I crank it to full power, it's only reading 4500w +/- a few watts

If a 9Kw 240v heater is running on 120v the watts would be 1/4 of it's rated power. 2250W
Is the 9Kw heater rated for 380v


Have you got a part# for the heater?

Am I just an idiot? Lol
My meter that I have wired into the box shows 125v 4500w at 37.xx amps. The circle bit that goes around the wire is only on the wire coming out of the ssr.

Is it possible it's only reading the voltage from that one line and the amperage is accurate, meaning that I DO have it wired correctly and it's only that one phase of the system that's seeing 4500w?

Now that I'm thinking about it, that sounds like the most likely scenario. I'll just have to multiply the wattage and voltage x2

[bcook608]

This makes even more sense when I think about the fact that I was able to boil 2 gallons of warm tap water in about 60 seconds...

Guys, I think I'm just retarded...

[bcook608]

The issue I'm running into is that it seems only 120v is making it through to the element. That, or I am having issues with my ammeter/volt meter and it isn't reading correctly. I'm going to have to pick up a multimeter and see if I can identify where the issue is. Right now when I crank it to full power, it's only reading 4500w +/- a few watts

If a 9Kw 240v heater is running on 120v the watts would be 1/4 of it's rated power. 2250W
Is the 9Kw heater rated for 380v


Have you got a part# for the heater?

Here's the element

[Bradster68]

This makes even more sense when I think about the fact that I was able to boil 2 gallons of warm tap water in about 60 seconds...

Guys, I think I'm just retarded...

Each hot wire you test should be testing at 120v. That's 240v total. 120v each side.