Can this be dOne ?

[lkayelectrical]

Hi guys need to feed a pool and spa install instead of 3 phase can you run 2 phases down as trying to cut supply down so it's not all on one phase?

Ie

L1 l2 and n? Will be split into 2 box's 1 for the spAr box one for the pool box

Just p

Wondering re the shared neutral? Or is it best to run 2 cables down?

Need min 32a for spar and 63a for pool

 

[SPECIAL LOCATION]

From the information given......

Oh yes it can be done............

Actually...

I have no idea if it will work for very long... :C

Cuz for all I know it may be a 2.5mm 400m run...... headbang

How much current do you envisage coming down this neutral????

How big is it?

whats your Volt drop on 63A?

What is the existing supply rating like for this load???

How well balanced do you reckon you phases my be????

Rule of thumb.....

If you are not able to design your own circuit.........

then..........................

...... well you know the rest...

No point saying more.....

:coat

 

[NozSpark]

Why not run a 3ph supply down to it and then use a 3ph DB?? Surely you have some other circuits you could attempt to try and balance the supply with?

But then again,, I'm with Specs...

If you're not comfortable with doing this kind of work then get someone who you can help out to do it,, and learn from it at the same time

 

[Andy™]

Hi guys need to feed a pool and spa install instead of 3 phase can you run 2 phases down as trying to cut supply down so it's not all on one phase?Ie

L1 l2 and n? Will be split into 2 box's 1 for the spAr box one for the pool box

Just p

Wondering re the shared neutral? Or is it best to run 2 cables down?

Need min 32a for spar and 63a for pool

if your running everything from 2 phases, then your neutral will probably be too small, in which case a larger CSA would be needed... so probably cheaper to get a 4c cable and use it as 2 lives & 2 neutrals. or go with 2 cables

 

[lkayelectrical]

Thanks think is best doing a 3ph and just trying to sort the house panel out (4 DBS on just one phase)

Not worked out vd etc as was wondering about wig that could be done,

Had no existing supply as its all new,

Dot alot of pool install before jut nothing quite as big as this one an as far from the house which is about a 60m run,

Think it might be best running 2 separate swa down

 

[park1]

Can't see no issue with the Neutral as long an each circuit is from a different phase.

 

[Doc Hudson]

Can't see no issue with the Neutral as long an each circuit is from a different phase.

From the above comment I would guess you have possibly never being taught about 3phase and unbalanced loads. Is this a consequence of modern short course, part P driven, training?

Doc H.

 

[park1]

From your comment you haven't a sodding clue.

It's just a polyphase circuit, a phase shift of 120 degrees, add up the current in the neutral using vectors smart ass, I think you will find it will not be greater than the highest of which ever phase.

Going of your posts though I know that's beyond you.

A little knowledge Is dangerous, as I said in another post, back up your claim, I know I can.

Well see who's the 5 week wonder.

You obviously don't design, a cable monkey maybe?

 

[Manator]

From your comment you haven't a sodding clue.It's just a polyphase circuit, a phase shift of 120 degrees, add up the current in the neutral using vectors smart ass, I think you will find it will not be greater than the highest of which ever phase.

Going of your posts though I know that's beyond you.

A little knowledge Is dangerous, as I said in another post, back up your claim, I know I can.

Well see who's the 5 week wonder.

You obviously don't design, a cable monkey maybe?

This is not the type of response that is welcome on this forum, from most of the one line responses it looks like you know a lot about a little.

The fact that the OP has asked here in the terms of his question it would equally be assumed that he would have no idea about a polyphase circuit, its implications and how to apply the maths to design it properly.

Perhaps you could explain the application and make us all happy.

Oh and this does not exempt you from receiving an infraction for your tone.

 

[park1]

This is not the type of response that is welcome on this forum, from most of the one line responses it looks like you know a lot about a little.The fact that the OP has asked here in the terms of his question it would equally be assumed that he would have no idea about a polyphase circuit, its implications and how to apply the maths to design it properly.

Perhaps you could explain the application and make us all happy.

Oh and this does not exempt you from receiving an infraction for your tone.

What about the docs insult? Is he exempt.

I dare say the op doesn't understand the math, I do and the neutral won't be an issues.

I don't intend on showing the math to add up neutral current using phasers and kickoffs law, I'll leave that for others to learn themselves.

---------- Post Auto-Merged at 21:37 ---------- Previous post was made at 21:32 ----------

Do you expect me to teach complex numbers and the j operator, phasers and vectors over a forum?

 

[Andy™]

Do you expect me to teach complex numbers and the j operator, phasers and vectors over a forum?

yes, since your clearly the expert on it around here

 

[Sharpend]

Wouldn't mind hearing what you have to say on it either. So when you are ready I'm all ears. Thanks in advance Sparks for imparting your knowledge to the good of others.

 

[park1]

Well think of it this way.

Assuming no imaginary numbers, no harmonics, just resistance.

Single phase, 10 amps, what current in the neutral.

Three phase 120 degree shift, 10 amp per phase, what current in the neutral.

Two phase 120 degree shift, 10 amp per phase, what current in the neutral.

 

[steptoe]

how about trying 32amp and 63 amp ,?

they are after all the figures the OP is dealing with. :|

 

[SPECIAL LOCATION]

how about trying 32amp and 63 amp ,?they are after all the figures the OP is dealing with. :|

and we don't even know what size cable yet ....

BUT...

don't worry boys cuz...

$parks says it will all be good......... :shakehead

 

[Joet1110]

so youll need 100a supply. How long is the run?

 

[park1]

and we don't even know what size cable yet ....BUT...

don't worry boys cuz...

$parks says it will all be good......... :shakehead

Specs, the resultant current in the neutral will be less than the largest load. So if he sizes the cable to the largest demand then as long as the Csa of the neutral is equivalent to that of the line then it will be fine. That's all I'm saying. Is that a problem, or is the problem you don't understand so let's be rude?