Three phase pwr

[rgum]

We now have Three phase in our new shed on our 3 acre mountain top home , Mnt dandy. Just with simple replies pls .....not too technical....ha he.....will I rack up a huge bill for electricity once I start thicknessing my used timbers I wish to re dress ? Is three phase really expensive and with this power phase will I be a very happy woodworker at home ? Cheer ( Been a long time since I was on ) Tony

[BobL]

We now have Three phase in our new shed on our 3 acre mountain top home , Mnt dandy. Just with simple replies pls .....not too technical....ha he.....will I rack up a huge bill for electricity once I start thicknessing my used timbers I wish to re dress ? Is three phase really expensive and with this power phase will I be a very happy woodworker at home ? Cheer ( Been a long time since I was on ) Tony

Have you got any 3 phase machinery to take advantage of this?
Either way it won't make any difference to your power costs.

[rgum]

Hi Bob. We've spoken before. Bk in 2oo6 ha he. No Machines yet. Just got our new 3 acre mortgage and home and sheds and 3 phase. Yay Busy shopping for a good size combo mach of just a thicky machine for all my older timbers to be dressed.With the home buy they threw in a new 48 " Gravely Zero turn to mow with. Phew ! So cost of 3 phase is not gunna make us a huge bill ? I'll look up 3 phase explained on the world wide womble somewhere. Good to know al about it. Educate myself. So cost is not bad you say ? Cheers Tony

[BobL]

Electricity is sold by the kWhr and a kWhr via 3 phase costs the same as via single phase.
Likewise, 1kW via 3 phase will do the same amount of work (i.e. thicknessing) as 1kW via single phase.

# phase motors are a little smoother, maybe a little quieter and old 3 phase machinery can be less expensive than single phase otherwise there is not a lot of difference.

[rrich]

I believe that three phase is more efficient than single phase. If it wasn't why would it even exist.

[BobL]

I believe that three phase is more efficient than single phase. If it wasn't why would it even exist.

It is more efficient but this really only kicks in for larger (i.e. industrial) size motors.
It is also supposedly smoother.

[rrich]

It is more efficient but this really only kicks in for larger (i.e. industrial) size motors.
It is also supposedly smoother.

Makes perfect sense.

Here in the US, because single phase is the normal electricity for residential distribution, used three phase machines tend to be cheaper. A single phase motor might cost $500 to $700 and make the total price of the used three phase machine too expensive.

[Albert]

Hi Tony

I have 3 phase installed a few months ago. The power company charge by the kWh you use. I notice there is a spike when I use my sander (11kw) + compressor (7.5kw) + extractor (4kw) for more than 2 hours in a day. But I have been working semi production in my workshop and the bill has never been an issue. Unless they charge you differently at where you are. Cheers

[rgum]

Thankyou Albert. Thankyou all. Much more confident that electricity bills for 3 phase won't kill our woodworking enjoyment.

[DSEL74]

How much did it cost to have the 3ph connected?

[Albert]

How much did it cost to have the 3ph connected?

well this varies case by case.

if its available on your street then the power company will charge between $3000 - $4000 to set it up for you. then you need your electrician to hook it up for you and all the hardware wiring, this can be between $ to $$$$$$$$$$ depends on how many machines you have and what kind of hardware you want.

Mine costed $6000 for the electrician alone, its for 30 m of 60amp cable run, 5 machines. new sub board. 5 X MCBs.... etc.

[DSEL74]

well this varies case by case.

if its available on your street then the power company will charge between $3000 - $4000 to set it up for you. then you need your electrician to hook it up for you and all the hardware wiring, this can be between $ to $$$$$$$$$$ depends on how many machines you have and what kind of hardware you want.

Mine costed $6000 for the electrician alone, its for 30 m of 60amp cable run, 5 machines. new sub board. 5 X MCBs.... etc.

There is 3ph on the pole directly out front of my house, so not sure if that would reduce the power companies $3000 - $4000???

It is at least 30m from the pole to the house/shed, but I already have 2ph so only need the additional phase in cable, the trench would still need to be dug again, but would need a new board fitted and wiring to points etc in the shed.

We were told that the shed had 3ph and that was a selling point as I already have 3ph machines. Unfortunately when we got here it turns out to be 2ph only. $10K is out of the question for my finances to have it connected!! I'm trying to understand what is involved in fitting VSDs to the machines. One for each machine adds up but you can get a lot of them for $10k

[BobL]

There is 3ph on the pole directly out front of my house, so not sure if that would reduce the power companies $3000 - $4000???

If they can use the existing conduit it should not cost that much

It is at least 30m from the pole to the house/shed, but I already have 2ph so only need the additional phase in cable, the trench would still need to be dug again, but would need a new board fitted and wiring to points etc in the shed.[/QUOTE]
I doubt they would just add the additional phase BUT they might be able to pull the 3P through the existing conduit so no trench redid might be needed.

I'm trying to understand what is involved in fitting VSDs to the machines. One for each machine adds up but you can get a lot of them for $10k

Even if you have 3P there are still a number of good reasons to use VFDs.

[Albert]

There is 3ph on the pole directly out front of my house, so not sure if that would reduce the power companies $3000 - $4000???

It is at least 30m from the pole to the house/shed, but I already have 2ph so only need the additional phase in cable, the trench would still need to be dug again, but would need a new board fitted and wiring to points etc in the shed.

We were told that the shed had 3ph and that was a selling point as I already have 3ph machines. Unfortunately when we got here it turns out to be 2ph only. $10K is out of the question for my finances to have it connected!! I'm trying to understand what is involved in fitting VSDs to the machines. One for each machine adds up but you can get a lot of them for $10k

Well if you already have 2 phase then it shouldn't cost too much. I already had 2 phase as well when I went ahead with mine. It's $300 from the line company to put in an extra fuse. The $3000 quote was for my other property that didn't have a plinth but has 3 phase buried.


A lot of the $6000 I spent is because the engineer I used spec'ed industrial quality fittings and wires. I went the conservative way as I don't want the house to burn down.

VSD can be expensive though. The Danfoss VSD I have for my big sander (38amp
) cost over $5000 when new.

[Albert]

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If they can use the existing conduit it should not cost that much

It is at least 30m from the pole to the house/shed, but I already have 2ph so only need the additional phase in cable, the trench would still need to be dug again, but would need a new board fitted and wiring to points etc in the shed.

I doubt they would just add the additional phase BUT they might be able to pull the 3P through the existing conduit so no trench redid might be needed.


Even if you have 3P there are still a number of good reasons to use VFDs.[/QUOTE]

why do you need vsd for each machine?

I only have 1 vsd and its for the monster 1100mm sande (18kw) I have it to limit the inrush current. Other machines I have range from 4kw to 11kw all without vsd. The 11kw is a sander it has star delta. Never had issues with my 60amp supply when it's turned on while the compressor (7.5kw) and the extractor (4kw) are operating at the same time