3phase generator v inverters?

[Lightning bolt]

As above - VFDs give you complete control of the motor, and have NVR and overload protection built in. Also, if you ever decide to sell the machines, you can advertise them as suitable for single or three phase supplies.

Having worked on a farm without electricity where I had to fire up the dirty old genny every time I wanted to use a power tool, I would go for VFDs every time. Also consider that you may wish to run more than one machine at once, so the genny will have to be rated for that, plus the extra loading that inductive things like motors will cause.

True 3ph versus ‘pseudo’ 3ph is pretty much irrelevant - VFDs produce a sort of chopped-up version of mains, but putting this through the windings of a motor smooths this out and will make zero difference to your woodworking. In fact, the soft start/stop functions will probably be kinder to the machines.

You guys have gotten my week off to a really good start. I have renewed confidence & vigor for this endeavor!
Thanks again for sharing your practical experience & insight

 

[Spectric]

Hi

Gennys have come a long way since the days of the so called noisy and dirty ones of the past but not always for the better! You get ones now that just purr and with a basic acoustic enclosure are really quiet but given the choice I would go for one with a big old Gardner 6LXB diesel, 10 plus litres and around 180Bhp at 1500Rpm and run forever as long as the oils kept clean. Used to be the engine of choice in many buses but now more often seen in fairground generators.

 

[Lightning bolt]

Ooh that was an expensive vfd! Post a pic of the motor terminals and someone can help you configure for delta and save you a bit more.

Marius Hornberger just did a video where he added. A VFD to his homemade bandsaw, key upsides for that job were variable speed (for cutting metals or plastics where you want it slower) ramp up time to prevent belt slipping at the start and braking to slow the blade down. His machine on its own took 20s to run down, with the vfd and the braking resistor fitted its now 1s.

Ive been looking at a vfd and older 3phase dual voltage machinery myself but keep umming and ahhing whether I have the time and patience to revive a cheap old machine that will still run great but is covered in a decade or more of surface rust, and then thinking about replacing the fence etc.

Pretty much all I know about vfd's, 3phase, induction motors etc... is on this thread! As a full-time carpenter/joiner it's getting v.disfunctional using other people's workshops. As I can't currently afford market price new or second hand machines, this seems the only option @ present...yes the palner thicknesser i've been offered is missing it's fence & half the housing for it...even free stuff has it's price!

 

[Spectric]

Hi

Thats great, qualified carpenters and joiners are whats needed, its something I am learning as my background is everything but wood, and it's a challenge that is harder to pickup than welding or software. Wood is just strange, it has grain, knots and cannot be welded plus it changes shape when you are not looking! Metal on the other hand is stable, remains straight unless bent and has known characteristics. Still undecided on whether wood or metal splinters are worse.

 

[Lightning bolt]

While I do use & appreciate metal, the wonderful world of wood is an endlessly fulfilling voyage of discovery! I suppose in one sense it's a more intuitive/feeling based trade/craft as opposed to scientific approach, I guess that's why engineers are so afraid of it!
I think metal splinters are worse...
Wood also smells good (most species) & is warm to touch, nice on cold winter mornings! Let me know if u need any wood advice

 

[Ttrees]

That sounds like some good news, thanks for it. Hopefully it'll be running by the end of the week & I can report my findings

Hello again
You want to buy switches for the Startrite if you want to be working on it by the end of the week.
Might need some longer 4 core wire to reach where the VFD is going, if its a distance from the motor.
You could buy a push button station, easily 15 quid, or make your own box from sheet metal,
and buy the likes of a green NO open push button, and a NC push button (red).
Type this onto that auction site
1Pcs Push Button Switch xb2-ba31
You could buy a twistlock mushroom NC one either, but you can make a handsfree paddle ..(hinged plank with dowel) with plain buttons like the suggestion.

You need some crimp connector eyes, and a pliers, or clamp the wires to make a flattened profile a slight fan shape, if using a regular long nose smooth sectioned pliers.
Some thin flex from a light fixture or doorbell wire for these are the only wires that are safe to touch,
and beware that the MAINS INPUT and MOTOR OUTPUT hold a lethal charge long after unplugging from the wall!
Large capacitors using DC high voltage take time to drain off.
It looked to me that Marius disregarded unplugging the VFD, maybe he did, but he didn't mention...
(Never disconnect or put a plug inbetween, as unplugging can let the smoke out.! )
No suggestion of him waiting for the caps to bleed, nor checked the terminals for a remaining charge when sorting the rotation of the motor.

You might want to make a sheet metal dust enclosure for that fancy VFD
and if you do, you could buy or find some cable glands (strain relief) while you're
at the shop.
Some wee hinges for the box and a bit of clear plastic for a window.

There is plenty of Startrite 275 VFD/inverter 3 phase threads with pictures on this forum if you look.

Have you a PT machine with two motors?
Is this fancier VFD more suited to that, and a Eastern one better for your Startrite?

Having mucho breaking capacity on your Startrite 275 might loosen the arbor nut on your blade.
I find mine stops quick enough with my cheapie 100 quid VFD without extra breaking resistor fitted.

Tom

 

[Ttrees]

Also best to ask if unsure about the correct parameters (motor commands)
most importantly the Hertz should be set to 50Hz as it relates to the speed of the motor.
Your pole number will be 2 if the motor is 3000RPM

And check that fence on the saw actually stays put after a few rips.
Mine locks down tight but loosens without warning.

 

[Lightning bolt]

Hello again
You want to buy switches for the Startrite if you want to be working on it by the end of the week.
Might need some longer 4 core wire to reach where the VFD is going, if its a distance from the motor.
You could buy a push button station, easily 15 quid, or make your own box from sheet metal,
and buy the likes of a green NO open push button, and a NC push button (red).
Type this onto that auction site
1Pcs Push Button Switch xb2-ba31
You could buy a twistlock mushroom NC one either, but you can make a handsfree paddle ..(hinged plank with dowel) with plain buttons like the suggestion.

You need some crimp connector eyes, and a pliers, or clamp the wires to make a flattened profile a slight fan shape, if using a regular long nose smooth sectioned pliers.
Some thin flex from a light fixture or doorbell wire for these are the only wires that are safe to touch,
and beware that the MAINS INPUT and MOTOR OUTPUT hold a lethal charge long after unplugging from the wall!
Large capacitors using DC high voltage take time to drain off.
It looked to me that Marius disregarded unplugging the VFD, maybe he did, but he didn't mention...
(Never disconnect or put a plug inbetween, as unplugging can let the smoke out.! )
No suggestion of him waiting for the caps to bleed, nor checked the terminals for a remaining charge when sorting the rotation of the motor.

You might want to make a sheet metal dust enclosure for that fancy VFD
and if you do, you could buy or find some cable glands (strain relief) while you're
at the shop.
Some wee hinges for the box and a bit of clear plastic for a window.

There is plenty of Startrite 275 VFD/inverter 3 phase threads with pictures on this forum if you look.

Have you a PT machine with two motors?
Is this fancier VFD more suited to that, and a Eastern one better for your Startrite?

Having mucho breaking capacity on your Startrite 275 might loosen the arbor nut on your blade.
I find mine stops quick enough with my cheapie 100 quid VFD without extra breaking resistor fitted.

Tom

Sweet! Wow, thanks for all that info. Amazing knowledge sharing on the global interweb of cosmic consciousness. I actually have a fella coming to help me who used to work in a stone yard & fixed their machines & does milking parlors too. I'm a little nervous when it comes to electricity/mechanics...but I'm sure he'll find all these posts useful too.
Thanks again, much appreciated

 

[Farmer Giles]

After getting a quote for 23K to install 3 phase to the farm, and got bored diving into the windings to find the star point to convert old three phase motors to delta so I could use a 240v VFD, I bought a 10HP Digital Phase Converter with soft start. The soft start helps with machines with larger start up loads. Most of my machines are low start up loads, I have a 50" Colchester lathe with 7.5HP motor and it works fine.

its wired to a 50 amp MCB. No moving parts apart from the cooling fan. I keep it in the hallway of the workshop so it avoids sucking in any dust, and is even quieter. I've had it about 4 years, no major issues, two slow blow internal fuses quickly replaced, usually happens during a power cut.

Cost just over £1000 from memory, however I bet there are cheaper Chinese DIY alternatives.

I don't tend use more than one motor at a time, unless you count the suds pump on the lathe, I could probably use the pillar drill and lathe at the same time but I'm not omnipresent so no need.

Cheers
Andy

 

[Ttrees]

Hello again
Nothing technical about it, but an understanding of the parameters.
Are you going making a cabinet for it?
You might have to add UKworkshop to these pasted links on a google search
but a step by step.
startrite-275-table-saw-conversion-3-phase-single-phase-t106896.html?hilit=inverter%20startrite&start=30

can-anyone-fit-a-3-phase-inverter-for-me-t109500.html?hilit=inverter%20startrite&start=15

3-phase-to-single-phase-startrite-275-conversion-from-3-ph-t91106.html

startrite-tilt-arbor-circular-saw-t88484.html

Tom

 

[Inspector]

Sorry for upsetting you pete! Am new to web forums & still figuring out where all things are/how they work, much like my OP on my workshop endeavors.

I'm not really upset Lb, just noticed a number of one time posts by people on a number of forums the last few days. I apologize for implying you are in that group.

There are good Chinese VFDs for reasonable prices that can be had for every machine you own or want and you would still be paying far less than a diesel powered generator. I now of a Aussie on another forum that has about 14 or so VFDs in his shop and has even gone so far as to replace single phase motors wth three phase and VFDs just for the extras the VFDs added. Running a dust collector at 60 cycle instead of 50 cycle giving a 20% increase in flow for example. A few years ago I bought a 4K unit for a 5 hp motor and it cost under $350Can/200 pounds to my door including the taxes. The brand is POWTRAN Technology You can buy through Alibaba as I did or direct, the way I'll buy next time.

Pete

 

[Lightning bolt]

I'm not really upset Lb, just noticed a number of one time posts by people on a number of forums the last few days. I apologize for implying you are in that group.

There are good Chinese VFDs for reasonable prices that can be had for every machine you own or want and you would still be paying far less than a diesel powered generator. I now of a Aussie on another forum that has about 14 or so VFDs in his shop and has even gone so far as to replace single phase motors wth three phase and VFDs just for the extras the VFDs added. Running a dust collector at 60 cycle instead of 50 cycle giving a 20% increase in flow for example. A few years ago I bought a 4K unit for a 5 hp motor and it cost under $350Can/200 pounds to my door including the taxes. The brand is POWTRAN Technology You can buy through Alibaba as I did or direct, the way I'll buy next time.

Pete

Sweet! No worries pete, I realise one has to be promt on thia modern technology. I am feeling v.optimistic now about my hopefully soon to be running startrite, I have been @ snailspace for the last 2yrs on a scheppach diy type saw (good value for €450) but not enough power for any chunky stock. Teatree also gave me some v.usefull info & links.
Thanks again for taking time on 'machines for dummies'...i'm slowly learning.

 

[nr_franklin]

Contact you grid suppler. I was quoted £1900 to have a 3ph supply installed and have the single removed. which I thought was really good considering. The other options are really 'poor' and they are such a compromise its not worth the hassle.

 

[DBT85]

Remember that it might not be as easy or competitive to get an energy supplier for 3 phase, apparently. I literally don't know if that's true just something I've heard.

Contact you grid suppler. I was quoted £1900 to have a 3ph supply installed and have the single removed. which I thought was really good considering. The other options are really 'poor' and they are such a compromise its not worth the hassle.

While actual 3 phase would be nice to remove the hassle, many are quoted much more to install it, I've seen people say they were quoted £15k. And just having 3 phase means you now don't have variable speed, soft start or braking on a lot of these machines unless you add it it which only brings back the hassle. I've watched some Startrite 275s go for £200-£300 in the last week. For under £400 with a vfd and a couple of hours fiddling you've got a great saw.

I'm not sure what the compromise is that you mention though. They run perfectly and in fact better than if they were on actual 3 phase.

 

[clogs]

just to add, a by product of running the generator is heat......
A good friend went to S Ireland and I fitted out for him a big genny on the back of a 7,5 ton truck.....
the genny had a Ford 6D engine.....once in Ireland the cab and running gear was sold for parts and the chassis set in concrete....In a big shed.....
the guy was a carpenter and wanted all his old Wadkin gear to go with him.......
he used the heat from the engine in his central heating system over the winter.....
the genny ran every day during working hours......after work they ran another but smaller D genny for electric.....
they were totally off grid, water from a well......

 

[luke burgess]

I ran a small worksop for years using a rotary convertor.
Six or seven machines.
Only downsides were turning the convertor on then the machine,two green buttons as apposed to one.
You could of corse leave it running all day.
If running multiple machines simultaneously i could overload and trip the convertor.
This only happned if there was more than one person working on the machines.
also had a vfd for my lathe that was very useful as it gave me variable speed.
given the choice the rotary would run everything...!

 

[Spectric]

The biggest advantage of a proper three phase supply in a domestic setting is power, rather than a single 100 amp supply you have three 100 amp supplies and the ability to run bigger industrial machinery with larger motors not just limited to 4Hp.

 

[Farmer Giles]

The biggest advantage of a proper three phase supply in a domestic setting is power, rather than a single 100 amp supply you have three 100 amp supplies and the ability to run bigger industrial machinery with larger motors not just limited to 4Hp.

I'm running 7.5hp+ off of a domestic single phase supply with the digital phase converter. Its rated to 10hp with a 50A 240v feed. Its a whole workshop solution, but I can only run one big motor at a time. I like it being 3ph 415v so no issues with star wound motors, however I would still have a mains 3 phase supply if the bill wasn't £23k!

 

[Spectric]

23K seems extortionate, when I had mine done it was around £1800 and even with inflation it would not be that high today. The main things that would ramp cost are distance and obstructions, the supply cable was outside my house, if they needed to cross a road that would have put things right up because you get involved with traffic management and highways but I assume yours must be either some distance or an overhead supply from a pole.

 

[Farmer Giles]

I have the overhead HT feeding the villages above me on the hillside going through my fields. Currently only one phase goes to the transformer feeding our property, and the transformer is designed only for one phase, so is it would mean a transformer swap. Otherwise it would have been somewhere between 2.5 and 4k based on what neighbouring properties closer to a 3 phase transformer have paid.