Electric Help question 240v

[Bubbles2]

I got my R2D2 here and looking to set it up with heat element. It came with a 5.5kw element. I have a 3 prong 40amp breaker (old dryer area)
I want to plug into that. Correct me if I am wrong please.

3 prong from socket, that 3 prong has 3wires (looks like 10g, grey, 3 prong off a dryer) 2 hots and a Green. 2 Hots go into that switch. That is what I'd like. Need to box it up.
https://images.thdstatic.com/catalog/pd ... ce122d.pdf
1st question above- That switch says it has a Withstands 1500V for 1 minute Dialelectric Failure. Is this 5.5KW element to much for it? IF so any other alternative without buying a 45.00 box? I like the inline switch idea. . .

From there into a Power Controller like this. https://www.ebay.com/itm/114308298133

From that controller then into my 5.5kw element which I noted that again only two sides to attach 120v per side, no White (is that the Common?) Gotta go look up Load and Line and Common. . . definitions. I've ran romex wired up a backfeed for my house feed generator, however the new 4prong stuff has red black white and green. Red and Black to a phase/leg, white to the ground and green for yet another ground.

My main concern of failure is that switch, but I did not want to plug in without a switch leg... I have looked high and low for this and thought one of you might know...
Thanks for looking in

[psf]

https://stilldragon.com/diy-controller-kit.html

This is what I use to control my 220V 4500W element. the instructions are for three wire configuration.

I didn't put a switch in mine but will one day. when I do I'm going to use a 30 amp single pole switchwired in-between the hot wire that goes str8 to the element. Just need to make sure it's a 30 amp.

[psf]

http://waterheatertimer.org/control-240 ... witch.html

[Bubbles2]

Thank you for the link, looks like a long read. No comment in regards to the failure of that switch I linked above?
That link is really cool... I see I can run a DPDT switch and forget the Power controller. . .. I am not clear if it matter which leg or hot goes to either side? Interchangeable? Does that switch just knock off one phase of the two? Where only one wire is hot? All those say 4.5kw MAX. . .I am using a 5.5kw

[psf]

It's too long of a read? It's literally explained in the first picture and the answer is right there. Handed you a spoon, I'm not going to feed you.

[Bubbles2]

No see above, I meant a lot of information and options... Please read above thank you again. I appreciate it.

P.S I am still reading over here. . .and I read fast. That link offers many options and tools and links and such.

[Salt Must Flow]

I have a 240V circuit in my garage wired through a double-pole 30A switch I bought at Lowe's if I recall correctly and it works fine with my 5500W element.

The wire you describe that has black, red, white (neutral) and green/ground is handy for controller projects that incorporate 110V for a fan, buzzer, indicator light/lights for instance. We just tap into one of the hot wires and use the neutral wire to complete those circuits. My Auber EZboil controller needs 110V to power it so I use that type of wire to supply my controllers.

[LWTCS]

Using a DPDT is not terrible in that it provides a way to modulate,,,,,,,awe who am I kidding?

A DPDT switch is Fred Flintstone tech.
Using a DPDT switch is a protracted approach to understanding that you'll eventually wish you had proper, 0 to 100% control over your heat input.

[Yummyrum]

1st question above- That switch says it has a Withstands 1500V for 1 minute Dialelectric Failure. Is this 5.5KW element to much for it? IF so any other alternative without buying a 45.00 box? I like the inline switch idea. .

The dielectric rating is all about how much voltage it can handle before it brakes down . You will only be 240V , way under its 1500V brake down voltage , so it will be perfectly fine .

[elbono]

/electrical engineer hat on

Wire colors in the US are:
Green - ground
White - neutral
Black - hot
Red - hot

The hot colors are not required by NEC but it is unusual to find others. NEC requires green or uninsulated to be ground and white to be neutral. It should be safe by this to touch green, uninsulated or white but I won't until I put a meter on it.

All exposed metal should be connected to ground unless it is "double insulated".

Circuit breaker load normally should be no more than 80%, preferably less. A 5500w heater the on 220 would draw 25 amps. 80% of 30a is 24a.

You want a double pole switch, it breaks both hots. I would size the switch by the 80% rule or bigger. If you have a fault it will likely be the first thing you try to kill power. Fault current is likely to be much more than 30a. A single pole will break the circuit but in a fault condition but the hot that needs to be opened has a 50% chance of being the other one.

1500v dielectric rating of the switch is irrelevant, it means if you apply 1500v somehow it won't arc internally and melt.

/Electrical engineer hat off

You can violate all the above and have a fully functioning system that is trouble free for a long long time. You probably won't use the full 5500w, your voltage will probably be closer to 240v. You probably won't need to hit the kill switch in an emergency, etc etc...

[Bubbles2]

Thank you all for the help I appreciate it. Thanks for letting me know or pointing out 1500v and 240v Got it now.
@elbono @yummyrum @Lwts, @saltmustflw @psf. Thanks again for your insight. I have thought about it and was pondering the DPDT and wondered if bring that 5.5kw up fast and then cutting it back to 120 via shutting a leg off was going to be good. Then I thought that it would be nice to have better control over a wash that is a bit viscous like Rye can be.
After the Fred Flinstone comment....I think I am going to Yabba Dabba Don't do it.

The rating is akin to 2x4's 1.5 x 3.5 actual. I do use 40 amp breakers for 30 amp services use 8 gauge instead of 10. Thanks for pointing that out too.

The switch is for the arc factor on plug in and turn off. This short thread really is full of info and the links that PSF share are a "Pinnit" I'd say. There is a ton of info in that link and the pics are like comics, so there is that too!

So all in all I guess I got the YES on that OP that is a fine setup. and no worry on the Dielectric. For some reason, I was thinking watts when I saw the 1500 in spite of the 240. Durka Durka. Must be a Lipid Tumor on my brain like the one on my back. . . Is that from Shine?

Appreciate all your help on this.

[Ben]

That 3 prong dryer outlet wont have a GFCI, you should really be wired into a GFCI for your still since you will be working around wet stuff. The most economical way is just to use a spa panel from somewhere like home depot, it will give you GFCI and you can use the breaker as your switch if required.

Normally if you are building a switch into a control box you would use a double throw double pole contactor (example: https://www.amazon.com/dp/B098DRZYJS?ps ... t_details )that is actuated by a smaller switch, the contactors can handle the constant duty loads with ease. Then you can use a low load switch (example: https://www.amazon.com/dp/B07C4Y1PS1?ps ... ct_details) to actuate it. It gives you control over both legs so you can still break off your 120v for misc accessories.

[elbono]

you should really be wired into a GFCI for your still since you will be working around wet stuff

This probably the most important thing to do. I can't believe I didn't have that in my list. The only excuse I have is I was on my 4th beer at the local pub. I'll take a chevron off my electrical safety officer patch ;- (

If you're unconscious or just frazzled from a good zap, you lost the most important link in the safety chain, YOU!

I've been thinking about going electric, I was thinking about a big red estop button on a contactor like you suggest. Definitely a good idea too.

[Skipper1953]

Ben beat me to it. GFCI is a must. A double pole switch or contactor controlled by a single pole switch is the only way to go. The switch always goes in the hot leg. If there are two hot legs, in my opinion, at least, safety demands a switch in both of them. If anybody feels that double pole switching is not entirely necessary, please consider that you may not get the chance to have a do over if you learn the hard way that you are wrong. Regardless of what other colors there may be, white and green/bare are ALWAYS neutral and ground respectively.
Elbono, if you were into your fourth beer, I would expect your hat may have been turned a bit to the side. I've seen that a lot with baseball caps.
Question: is the derating to 80% needed for a dedicated circuit? I ask because I don't have one of those hats.

[ZeroTrousers]

Okay, so for thing is first:

Household 240v is two hot wires and one neutral. Each hot wire is 120v when measured against the neutral but it's 240v when measured against each other. You don't need the neutral unless you have 120v requirements in your setup - the reason dryers and stoves have this neutral is for their 120v components.

Next: every circuit that has a 240v load *must* have a Double Pole switch. If it's going to be an on/off control, you will use an appropriately rated Double Pole Single Throw (DPST) switch as your main power on/off switch. You need a switch that is rated for a minimum of 240v (this is a minimum, higher is better) and the total system amperage plus 25%, or breaker max plus 10%, again higher is better.

Any other switching controls in your setup have to be similarly rated - SCRs, contactors,etc.


If you have any questions, this is right up my alley.

[elbono]

Regardless of what other colors there may be, white and green/bare are ALWAYS neutral and ground respectively.
I would expect your hat may have been turned a bit to the side. I've seen that a lot with baseball caps.
Question: is the derating to 80% needed for a dedicated circuit? I ask because I don't have one of those hats.

Well white, bare and green are not ALLOWED outside of ground or neutral circuits. I've found some pretty strange stuff in residential settings. Bare is pretty safe to touch but I've been bitten by white several times and green at least once. I learned the hard way to always put a meter on it. Residential level shock is fairly unpleasant but rarely fatal UNLESS you are well grounded which you may be in a wet location. Try touching 480v AC or 300v DC and you get a real respect for electricity. I think 300 DC is most painful I've had, DC tastes entirely different from AC. Of course I was on a ladder too, lots of cussing, dancing and shaking my arm on that one when I got off the ladder.

The 80% thing is not a derating in this case, it is based on how cicuit breakers work. Most (especially in residential) are thermally operated. The current heats up an element, when it gets too hot the breaker trips.
They are designed so if the current is over the trip level (the 30A in a 30A breaker) they trip quickly, 1 second or less. At the trip level it may take a few seconds. At CONTINOUS current of 80% of trip level they may trip in about 3 hours. Just about when the still run is well under way...

You can find breakers with a continuous rating but they're uncommon and more expensive. Fancy electronics inside.

In my part of the world a hat is whatever is on your head. A cap is the funny looking thing cockneys wore in old movies. I was wearing a "baseball cap" and it was very likely not well aligned.

[Skipper1953]

Elbono,
Thanks for your reply.

[Oldvine Zin]

Try touching 480v AC or 300v DC and you get a real respect for electricity. I think 300 DC is most painful I've had, DC tastes entirely different from AC. Of course I was on a ladder too, lots of cussing, dancing and shaking my arm on that one when I got off the ladder.

Ha Ha I remember the first time that I put my wiggy on a 600 dc tap thinking that is was 240 ac, damn that was scary.

Stay safe
OVZ

[ZeroTrousers]

Ha Ha I remember the first time that I put my wiggy on a 600 dc tap thinking that is was 240 ac, damn that was scary.

Stay safe
OVZ

Jeez, I work with 3ph and high voltage DC regularly. Touching 600v DC at anything over a few milliamps and you're lucky to still have a pulse.

[Oldvine Zin]

Yea it was in an old projection booth that had back in the day carbon arc projectors. that incident taught me a new respect for electricity

Stay safe
OVZ

[Yummyrum]

Interesting OVZ
I used to work as a projectionist back in the day and we had Carbon arc lamp house too , but the voltage was only around 60-80v ( current was up too 100Amps )

Under each projector there was a box which housed a big 3phase transformer that dropped down from 400V to 60V followed with massive big rectifiers . There was a clunky big switch that you could select the voltage and hence the light output .

Lol , my boss was a tight ass and he would demand wringing the last drop out of every rod . Got really proficient at changing out rods in the middle of a spool of film . Patrons got used to a few seconds of dark scene every now and then .

Just curious how and where you contacted 600v DC?
Was that what was feed to your rods ? Seems high .


We did have a small projector with a Xenon tube in it that ran several hundred volts but there were many interlocks on tube housing access that you could never contact HV while covers open .

[elbono]

Don't know what OVZ was into but when I found out what 300V DC feels like I was working on a 200 HP variable speed motor drive. The field was 300V, the armature was 500V at full speed, glad I didn't find out what 500V DC feels like. The armature circuit could put out close to 400A.

I think his "wiggy" was one of the old solenoid/buzzer/lights voltage testers. Probably melted.

[Bubbles2]

Wow this one went off to memory lane. . . LOL Thanks for the advice on all that. I bought a double Pole 30amp for my switch leg. (both lines are cut when thrown) I am now curious about this potentiometer (pot switch) The ebay link above for the controller, for the 115x2 30 amp Line.
My load is 5.5kw which I prob will only go 80% till temp reached. I bought it and the SELLER decided to answer after I asked if that would work inline hardwired and he just said NO sorry it won't after selling it to me with no return option. Does the Seller know what they are talking about? It is 230v 10kw

Specs-
AC 110-230V 10000W SCR Motor Speed Controller Volt Regulator Thermostat Dimmer
10000W SCR voltage Regulator, come with a smart fan and a aluminum-alloy case, high power electronic voltage
regulator, It is suitable for lighting engineering control, heating wire, boiler heating control, power tool motor control, etc.

Features:
The trigger circuit is unique, the control voltage regulation is accurate without hysteresis, and the resistive load is adjusted
from 10V after it is turned on from 0, and the maximum is close to the input power voltage

SCR adds RC absorption protection circuit
Upgraded fan with switch intelligent control, good cooling effect and long service life
Standard high-grade exquisite aluminum shell is more safe and practical

Parameter:

Operating voltage: AC 110V-230V
Maximum power: 10000 (connect Resistive load)
Voltage regulation: adjustable between AC 0V - "close input voltage"

[Salt Must Flow]

I've never used an SCR before, but based on the wiring diagram that's shown in that listing ... it appears to me that line 1 and line 2 goes in and line 1 and line 2 goes out to the heating element. Line 1 and 2 should be the red and black wires each being 120V. Like I said, I've never messed with any SCR. I always use Solid State Relay based controllers.

[Bubbles2]

@Saltmustflow. .. I thought the same as you. I had asked the seller if that would handle my application. Did not get an answer, read the specs 230V 10kw So I figured it should work. I bought it figuring it was just a lazy seller (as usual) and then they replied back "SORRY THIS IS NOT FOR YOUR APPLICATION. Hence me coming to ask someone over here. I have the unit here and figured the wiring as you stated. . . Are missing something? I saw it as mentioned above. . . ?

[Oldvine Zin]

@Saltmustflow. .. I thought the same as you. I had asked the seller if that would handle my application. Did not get an answer, read the specs 230V 10kw So I figured it should work. I bought it figuring it was just a lazy seller (as usual) and then they replied back "SORRY THIS IS NOT FOR YOUR APPLICATION. Hence me coming to ask someone over here. I have the unit here and figured the wiring as you stated. . . Are missing something? I saw it as mentioned above. . . ?

As long as you don't overload it it should work OK

Stay safe
OVZ

[elbono]

We're getting into terminology here. I consider a SSR a device that is either on or off. In your case either 0w or 5500w. A power controller is basically the same thing only it adjusts between 0 and full power. Both use SCRs, TRIACs, IGBTs, power MOSFETs or similar devices and terminology again is fungible.

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. The only draw back I see is the 10v minimum on voltage which will be 250w, shouldn't be a problem and controllers that go closer to zero will cost more. The sellers response may be "if you don't know, I don't want to take responsibility"

When I put together stuff with inexpensive components I do a mock up before fitting everything in the final configuration. Screw stuff to a piece of wood an make sure it works like I think it will. You can try it on 120v, power cord black and white to ac in, ac out black and white to a receptacle (wall plug from home depot or lowes) plug a cheap lamp (old fashioned incandescent not led or cfl) into it, plug in the power cord, turn the pot see what happens. Hopefully you go from a dim glow to full brightness. Don't touch any metal or you may have a new stop on your memory lane.

If you get past the 120 mockup you could do similar with 230. If you use your heating element make sure it's in water, they burn out in a heartbeat in air.

The 80% stuff is probably not going to affect you, it's all on worst case, low end of voltage, heater resistance, breaker trip specs. If you run it it full blast and the breaker trips after a while you know you can't do that. Run less than full blast.

[Oldvine Zin]

The sellers response may be "if you don't know, I don't want to take responsibility"

Stay safe
OVZ

[Bubbles2]

Elbono,
Makes good sense, I will do just that, 120 Black and White via an outlet, for power and some sacrificial lamb for the test. Thanks for looking in and your input. Thanks OvZ.
Looking forward to doing the wash.

[elbono]

Just make sure the scarificial lamb is "dimmable", led bulbs, cfl's and other new stuff may switch on when they reach a threshold and not show a gradual response. Old fashioned filament bulbs, heating pads etc should taper up.

Since you likely won't have all the grounding and other safety measures in place be careful. It would be good to plug it into a GFCI protected outlet as well.