3 Phase power questions

[DeafSmith]

Here's what I think are the voltage and currents. Notice how the line current and element current is 30 degrees out of phase. Also the terminal voltage to "neutral" multiplied by line current is the same as the element voltage multiplied by the element current (same power) as it of course must be.

EDIT: This is for the elements connected in a delta configuration, 240 v line to line.

 

[P-J]

All,

I'm still confused beyond belief.

I just put the original diagram back in place (page 2).

I drew the diagram for using 240V 3-phase power (240V Delta transformer) as the system input.

When I illustrated the wiring within the controller, the elements are connected in a 'Y' configuration. This resulted in the actual voltage presented to each element as 208V. The elements chosen for the diagram are 5500W-240V.

Now after doing days of digging through my mess, I think I understand that I will need 40A breakers instead of the 30A shown. Each element will be drawing 19.95A, so for the set of 3 elements they will draw a total 34.34A per line from the 240V Delta power input.

I think.

Damn... I'm still confused.....

I'm have one hell of a time wrapping my mind around it all.




P-J

 

[DeafSmith]

All,

I'm still confused beyond belief.

I just put the original diagram back in place (page 2).

I drew the diagram for using 240V 3-phase power (240V Delta transformer) as the system input.

When I illustrated the wiring within the controller, the elements are connected in a 'Y' configuration. This resulted in the actual voltage presented to each element as 208V. The elements chosen for the diagram are 5500W-240V.

Now after doing days of digging through my mess, I think I understand that I will need 40A breakers instead of the 30A shown. Each element will be drawing 19.95A, so for the set of 3 elements they will draw a total 34.34A per line from the 240V Delta power input.

I think.

Damn... I'm still confused.....

I'm have one hell of a time wrapping my mind around it all.

P-J

P-J, with 240 volts across the legs of the wye, the line to neutral voltage is only 138.6 volts; i.e., 240/sqrt(3), not 240*(sqrt(3)/2)).

 

[P-J]

P-J, with 240 volts across the legs of the wye, the line to neutral voltage is only 138.6 volts; i.e., 240/sqrt(3), not 240*(sqrt(3)/2)).

Awwww... Crap! Damed if I didn't blow it again.!

This whole thing is a pain to my brain.
Getting old just plain sucks.

I just posted a note on the smaller front diagram of my post on page 2 (this thread). I left the large image in tact.

So, now with all of that, I drew a new diagram that is hopefully correct. The power configuration is still 3-Phase 240V but is now a Delta - Delta configuration. Hopefully I also figured out the correct amperage required for each Phase that must be delivered.

Thank you all for putting up with my stupidity.

First thing is the basic power layout to the elements.

Next is the diagram redrawn for a Delta - Delta wiring layout.

And - As always - Click on the image to see a full scale diagram printable on Tabloid paper (11" x 17")



All: Please let me know if I fixed some of my mind twists and got it correct this time.

Thank you all for your patients with this old man (Now just 3 months shy of 73).

Thanks!

P-J

 

[DeafSmith]

Thank you all for your patients with this old man (Now just 3 months shy of 73).

Thanks!

P-J

Yeah, I know what you mean - I had to draw the timing diagram before I felt like I really understood it. And I'm a relative youngster, only 66.

 

[grandequeso]

I think colors around the ssr and the elements are a little bit confusing. It would be a little easier to follow if the same color phase came in and out of the ssr and the wires going to the elements were opposing phase colors. The color configuration of Black, Red, Blue is the common 120/208 wye colors in the US. But when running 120/240 Delta you will have a high leg (approx 210v line to neutral) this leg is not to used for line to neutral loads, but it must be identified by being colored orange or tagged as being the high leg. Typically it is placed in the center phase in a panel. (Some places go black, orange, blue. Others use Black, orange, red.) I would recommend placing a note in the schematics to make damn sure that was not the leg that was feeding your pumps and controls. Besides that, looks pretty good.

Grandequeso

 

[P-J]

I think colors around the ssr and the elements are a little bit confusing. It would be a little easier to follow if the same color phase came in and out of the ssr and the wires going to the elements were opposing phase colors. The color configuration of Black, Red, Blue is the common 120/208 wye colors in the US. But when running 120/240 Delta you will have a high leg (approx 210v line to neutral) this leg is not to used for line to neutral loads, but it must be identified by being colored orange or tagged as being the high leg. Typically it is placed in the center phase in a panel. (Some places go black, orange, blue. Others use Black, orange, red.) I would recommend placing a note in the schematics to make damn sure that was not the leg that was feeding your pumps and controls. Besides that, looks pretty good.

Grandequeso

Grandequeso,

Thank you so much for your guidance. It is very much appreciated.

I redrew the diagram (above in post #64) with the changes that you suggested. I ended up using orange for the high leg and then chose blue and red (instead of black and red) which made my life a tad easier redoing the diagram.

You helped clear up a lot of confusion spinning in my head.

Thanks.

P-J

 

[tannnick]

Reviving this thread, P-J, are you confident in that above diagram? I PMed you with some updated info. I would like to use this same setup but in a 208v setting with 6000w elements. Thank you.

Anyone else have luck with this yet?

 

[P-J]

Reviving this thread, P-J, are you confident in that above diagram? I PMed you with some updated info. I would like to use this same setup but in a 208v setting with 6000w elements. Thank you.

Anyone else have luck with this yet?

Just sent you a PM. Finished a diagram with your latest specks and would like to e-mail it to you to see if it fits your needs...

 

[Livingstone12]

Sorry, I don't mean to offend Huntb, but that is entirely incorrect. You are showing single phase wiring, and it's incorrectly labeled.

Cruelkix, I've built three phase control panels before, and it's not that hard to do. A fully variable controller with individual element selectivity and control and PID integration is as complicated as I've built yet, but it works. One thing you will need to do is run three elements per 3ph circuit. You state you want to run 6 5.5kw elements, where would each element be?

If you are interested in what a 3 phase panel could look like, here's one I built not long ago.

View attachment 72501

View attachment 72502

Hello,

Tried accessing your site, no success. I'm interested in a 3 phase one PID two Elements controller.

Could you get in touch?

Thanks.

 

[rsquared]

Hello,

Tried accessing your site, no success. I'm interested in a 3 phase one PID two Elements controller.

Could you get in touch?

Thanks.

FYI, this thread is from 2012, and they haven't posted since 2013, and not logged on since 2017...

 

[Livingstone12]

FYI, this thread is from 2012, and they haven't posted since 2013, and not logged on since 2017...

Yeah I realise. Thanks.

Was just hoping, for a response.

 

[Livingstone12]

Also

Yeah I realise. Thanks.

Was just hoping, for a response.

Also anyway you could assist re my request.

Would appreciate that. Thanks.

 

[Maxkling]

Also


Also anyway you could assist re my request.

Would appreciate that. Thanks.

It would help if you made a new post with details like what voltage how much power you need.

 

[Livingstone12]

It would help if you made a new post with details like what voltage how much power you need.

Thanks for your response. I hope this will do.

Pot (water) volume: 80l
Voltage supplied is 415 V 3 phase.
Power needed: 18 kW.

In terms of heating element, I'm considering the round heating types like the ones sold by Brewpi.

Thanks.