Electric Help question 240v

[NormandieStill]

Looking at the ebay link I see nothing that indicates it isn't appropriate for your plans. You have a resistive load well below the 10kw max.

For the record the advertised 10kW max is likely to be marketing BS! WhenI took a look at what was in my "10kW" SCR the components were rated for half that and not under continuous use. It will also depend on the effectiveness of the heatsink. If you think you might want to push the system to run 5500W for some time I would stick a fan in the case to help keep the heat down or your SCR will probably just fry.

[elbono]

I took the ebay description as truthful but some of the stuff sold on ebay does use an alternative version of the truth.

My first thought was I would remove the "intelligent fan"' brain and make it run all the time. Since this will likely be mounted in a small enclosure the enclosure needs a fan as well.

[Bubbles2]

Thank you, They do make dimmable LED's now, but I gotchya. I'm so old I still have filament bulbs. Like the One's you have to "Score" in an ally behind a hardware store...LOL Last Man Standing - Episode

[Bubbles2]

I am wiring up the whole thing and wanted to ask.
I have a 55kw heat element. On the wire up end, I have ONE side that has 3 in series elements the Other side the same ( 3 series connected via tabs in series.)
So ONE 120v runs one side and the other 120 runs the other side. There is a threaded stock through the center and a plastic cap covers the exposed 120 series. Is that what I connect a neutral to? I hear there is no ground in 240v but thought to ask if a neutral is usually connected there. Since old plugs have 3 Prongs 2 hots and a Neutral. No Pics allowed to upload that I can see here.

[Ben]

You ground directly to the body of your boiler, or at the thread in section of the element. Do not run without a ground. In the case of a short or wiring issue you'll touch the boiler and become the ground.

[Bubbles2]

Thanks for the reply. So-- Yes green to then Center Post which runs back to the Ground bar in the Box, which is grounded via a grounding rod in the ground. Appreciate the help

[elbono]

As Ben says make sure you ground the whole thing. I can't tell from your description exactly what the "threaded stock" is, if you have an ohmmeter use it to be sure it is actually grounded. Measure from it to the pipe threads.

On things that are "pure" 240v there is no neutral connection. Appliances use the neutral connection for 120v circuits. Neutral is 1/2 way between line 1 and line 2. This diagram may help.

120V-240V-Single-Phase-Power-Sketch.png (9.34 KiB) Viewed 844 times

In the past 240 plugs had no ground, they used the neutral connection as ground. This is safe in most cases but when things fail it might not be so the NEC was changed to require the ground.

It took me a while to figure out how to attach photos. Use the Attachments tab just below the area you type in then use the Add files button. Here's a screenshot of how it looks on my phone.

Reduce the resolution if it's a high quality photo I use ImageShrink but there are lots of apps to do that. Here's the post that covers image resolution in detail. viewtopic.php?f=35&t=19897

[NormandieStill]

On things that are "pure" 240v there is no neutral connection. Appliances use the neutral connection for 120v circuits. Neutral is 1/2 way between line 1 and line 2. This diagram may help.
120V-240V-Single-Phase-Power-Sketch.png
In the past 240 plugs had no ground, they used the neutral connection as ground. This is safe in most cases but when things fail it might not be so the NEC was changed to require the ground.

Putting this out there for future readers. The above is true for North America (USA. Canada?) and IIRC Japan. Europe runs on 220v (often called 240v) and has a phase and neutral line.

I'd second checking the "threaded stock" to check that it connects to the case. Might save a loud bang. Can you post a photo of the element. It sounds a bit like the one I use.

[elbono]

The above is true for North America (USA. Canada?) and IIRC Japan. Europe runs on 220v (often called 240v) and has a phase and neutral line.

I'm definitely speaking for the US. I should have specified that.

I have some very limited experience in Europe and Britain. There 230v or close is the routine household voltage between neutral and hot. I believe residential systems there are also split phase and have a higher voltage available hot to hot that would be 460 or so. Of course it's 50 hz as well.

[NormandieStill]

I'm definitely speaking for the US. I should have specified that.

I have some very limited experience in Europe and Britain. There 230v or close is the routine household voltage between neutral and hot. I believe residential systems there are also split phase and have a higher voltage available hot to hot that would be 460 or so. Of course it's 50 hz as well.

Britain was traditionally 230v I think, but in theory Europe is standardised on 220v (nominal, I get anything up to 245v here in rural france depending on how many of the neighbours have the radiators on!). But we don have split phase, we have 3-phase. If I so desired (and was prepared to pay the costs) I could have 3-phase into the house. That puts you at 380v nominal phase-to-phase.

[elbono]

I'm definitely speaking for the US. I should have specified that.

I have some very limited experience in Europe and Britain. There 230v or close is the routine household voltage between neutral and hot. I believe residential systems there are also split phase and have a higher voltage available hot to hot that would be 460 or so. Of course it's 50 hz as well.

Britain was traditionally 230v I think, but in theory Europe is standardised on 220v (nominal, I get anything up to 245v here in rural france depending on how many of the neighbours have the radiators on!). But we don have split phase, we have 3-phase. If I so desired (and was prepared to pay the costs) I could have 3-phase into the house. That puts you at 380v nominal phase-to-phase.

That's the piece I forgot, British 3 phase is 415v phase to phase which gives 230 phase to neutral. Mainland 380v phase to phase gives 220v phase to neutral. I remembered British industrial at 415v from when I worked there but forgot about the 380v I saw on Italian equipment we imported to the US.

One thing we all have in common is the voltage you read on the meter will almost never be nominal!

[Bubbles2]

AWESOME thanks @Elbono for sharing on how to attach a pic ! this is what I described. The Threaded stock is circled.

[elbono]

The only time I would connect neutral there is if i didn't have a ground and couldn't get one.

It is very likely connected to the "enclosure" which you want to ground but it could be insulated from everything. You definitely want to ground that since it will be exposed the only question is if that will ground the boiler as well.

I said to test from it to the threads but it looks like you have clamp style so test to the flange the clamp holds. Ohmmeter, test light, whatever. If the end I can't see in the pic is screwed into metal I would consider it connected to the flange. If it's screwed into plastic it's probably isolated.

Looks like they only sent one nut, get two more so you can sandwich the connection between them and use the one you have to hold the cover on.

[Bubbles2]

@ELbono, Thanks for the get back and follow up I appreciate the time. I have more nuts to secure, thanks.

The Unit appears from the outside to be threaded into the unit (see pic) I do not see an insulator as I do on the Hot legs.

The Green wire and Two Hots are what I have for the old style 230v U.S style Dryer Plug. I do think it is as good as a White and only a secondary for the white. The reason I state that is The green wire ties right into the Neutral Buss in the Box along with the White(s). Everything in that Aux box has 230v. A/C, Pool Pump, Generator Back Feed, and this one a Dryer. That bus is also grounded into a ground rod driven 12' into the ground and has a green wire from the rod to the Buss. I feel that is a good ground.
The only other safety feature that I could do is a GFCI if too much is drawing it will shut off. However I do have some built up immunity to being electrocuted FWIW. . . LOL I did my neck with the Main line of the Pole that feeds the MAIN box 5years ago painting. My neck was just barely touching the main feed (unbeknownst to me at the time) Then I grabbed the ladder for balance and I am sure the rubber boots helped. . . Close One for sure. Almost ended all my chores all in one Zap. Laughing about it now, but not a joke for sure. Hence me asking for help.

That unit is clamped with stainless to the Pot. So I would thing all that is not insulated Should be grounded by that post via Green Wire that is connected throughout the set up. Dryer Plug> 2 Pole Switch> Potentiate/dimmer (which only has two hots in and two out) So I ran some sheet metal under the unit and then it connects to another plug that goes to the Pot. All tied up to that Green ground.

Better View of connect

Layout need to go get #10 to finish

[Bubbles2]

@ELbono, Thanks for the get back and follow up I appreciate the time. I have more nuts to secure, thanks.

The Unit appears from the outside to be threaded into the unit (see pic) I do not see an insulator as I do on the Hot legs.

The Green wire and Two Hots are what I have for the old style 230v U.S style Dryer Plug. I do think it is as good as a White and only a secondary for the white. The reason I state that is The green wire ties right into the Neutral Buss in the Box along with the White(s). Everything in that Aux box has 230v. A/C, Pool Pump, Generator Back Feed, and this one a Dryer. That bus is also grounded into a ground rod driven 12' into the ground and has a green wire from the rod to the Buss. I feel that is a good ground.
The only other safety feature that I could do is a GFCI if too much is drawing it will shut off. However I do have some built up immunity to being electrocuted FWIW. . . LOL I did my neck with the Main line of the Pole that feeds the MAIN box 5years ago painting. My neck was just barely touching the main feed (unbeknownst to me at the time) Then I grabbed the ladder for balance and I am sure the rubber boots helped. . . Close One for sure. Almost ended all my chores all in one Zap. Laughing about it now, but not a joke for sure. Hence me asking for help.

That unit is clamped with stainless to the Pot. So I would thing all that is not insulated Should be grounded by that post via Green Wire that is connected throughout the set up. Dryer Plug> 2 Pole Switch> Potentiate/dimmer (which only has two hots in and two out) So I ran some sheet metal under the unit and then it connects to another plug that goes to the Pot. All tied up to that Green ground.

*Note- I Multi metered with OHMS and when connecting One lead to where a Hot Leg will be and the other to that threaded stock. Nothing. This is true for both Hot legs. IF I connect the Lead to the Threaded stock and then to the edge where the clamp will be I get a 5. I also get the same when connecting to the tubes that will immersed. I also checked the Prongs which are already wired up via Touch one of the Prongs that would go in the Plug for juice and to the (In Question Threaded Stock for ground) Nothing. So definitely isolated via plastic spacers for the elements.
So I think I am good. Thanks again for help. I will add a pick after it is wired up for someone who may be doing the same thing next week. Appreciate all the input and help from Y'all.

Direct.JPG
layout.JPG

[Bubbles2]

Here is the final assembly, just in case someone is trying to put one together. I thought there was some good info on this thread from all the input.

Ohm test was really enlightening.- easy find on youtube How to.

Using a 10k riostat/dimmer for 240, test first on a throw away old filament bulb.

Not going with the Yabba Dabba Don't of switching half the leg off to decrease power for half, getting the potmeter was the way to go.

Anyhow Thanks Y'all.

This set-up allows me to unplug the Pot and put the cord and element into the Pot, all put away.
The switch can hang from the wall in the utility room.

I got two dryer cords, used 10.00 for two.
dryer receptacle 7.50
240 2 Pole switch 17.00
Make up Box 2.50
Wire 5' of #10 5.00
The Potmeter was 25.00 (came with a fan) cheaper if you skip the fan
Neutral wire had laying around or add another 3.00.
Lesson-Priceless.

I am now ready to make distilled H2o. . .

[Yummyrum]

Looks good to me Bubbles . Just hope you don’t have any little kids that might want to stick their fingers on those terminals on the controller.

[elbono]

I think you've got it in hand. Last comments:

Give any crimp connectors a good tug, they're easy to mess up.

Consider a GFCI supply (spa or pool subpanel) it will cut power before you even feel a shock, much less get hurt by it. They're not very expensive.

Yeah, as Yummy says put that in an enclosure, I hope you already plan on that.

Next time you're painting beg, borrow or steal a fiberglass ladder. Aluminum ladders are cheap but a deathtrap around electricity. Your reaction to a shock is more likely to cause injury than the shock, glad you didn't jump/fall off the ladder. I've been bitten many times but my tolerance doesn't seem to have changed I still spew curse words every time.

[Bubbles2]

I plugged it in (less Element) Tested with meter. Touched everything with probe and hands nothing hot, no zap. all is good. I am too old for kids. So it is just me, the dogs and the chickens. Life is good, I know my rancher and have a victory garden.

Thanks for saying it looks good. Not exactly a Kazinski sanitary wire job, 1st time.

The Potmeter has no resistance as when I tested with a bulb,(due to no load from the element YET) so 240v to the plug for the Pot. Fan runs on the dimmer and switch makes no Pop. My arm hurts from patting myself on the back....

I might nail a couple 2x's to the bottom to get it 1.5" off the floor. Incase of a spill over. I think the breaker will 'POP' if there is a circuit issue.

I was on a fiberglass ladder. . . Maybe it was the roof I grabbed. That moment in my life is erased. . .