Phase convertors?

[Jared Sankovich]

Spoke to someone at PP today and got some info....couple of quick questions.....

Why do I need an 80 amp breaker for a 10hp PP that only draws 30 amps? Am I missing something there?

2) Can one of you explain to me how I could make a VFD work for this machine? I guess I don't quite understand how it becomes a phase convertor so that I can run a 3p machine off my single power?

Thanks everyone!

It draws more than 30amps. If it outputs 30amps 3ph (10hp) it's at least 30x1.8 for the input (plus any losses)

[Kurt Wyberanec]

OK, so this sounds like I will remove VFD from my plan. So that leaves Static, Rotary, and Digital (Phase Perfect)...

I am still trying to understand how this would have to be hooked into my current subpanel...what size breaker I'm going to need, and if the panel is big enough for it. Some of you said it is 1.8 to 2x conversion...when I asked PP about this they told me that it will draw about the same amount as the saw, then I asked why the breaker needs to be so big and they basically said it's just in case protection and that it really only makes a difference for the start up. They claim virtually no efficiency loss. This doesn't quite make sense to me...the unit has to be using power to make some I would think (hence the multiples some of you mention) which makes sense to me but contradicts what they said. At the end of the day I'm trying to figure out if this is going to require me to have an electrician upgrade my panel to handle more amps and if that's the case then it just continues to increase the expense.

I also don't quite understand whether or not the cheap static convertors can work and if they have any potential risks. Again, I'm really thinking this is going to be a single tool most likely with a separate scoring motor and that would probably be a 5-7.5hp main and .5 to 1hp scorer. There's an off chance I would go for a bigger saw if the deal were right but I just don't think I need it at least at this point in my shop.

Again, any thoughts much appreciated. Thanks!

[Jared Sankovich]

OK, so this sounds like I will remove VFD from my plan. So that leaves Static, Rotary, and Digital (Phase Perfect)...

I am still trying to understand how this would have to be hooked into my current subpanel...what size breaker I'm going to need, and if the panel is big enough for it. Some of you said it is 1.8 to 2x conversion...when I asked PP about this they told me that it will draw about the same amount as the saw, then I asked why the breaker needs to be so big and they basically said it's just in case protection and that it really only makes a difference for the start up. They claim virtually no efficiency loss. This doesn't quite make sense to me...the unit has to be using power to make some I would think (hence the multiples some of you mention) which makes sense to me but contradicts what they said. At the end of the day I'm trying to figure out if this is going to require me to have an electrician upgrade my panel to handle more amps and if that's the case then it just continues to increase the expense.

I also don't quite understand whether or not the cheap static convertors can work and if they have any potential risks. Again, I'm really thinking this is going to be a single tool most likely with a separate scoring motor and that would probably be a 5-7.5hp main and .5 to 1hp scorer. There's an off chance I would go for a bigger saw if the deal were right but I just don't think I need it at least at this point in my shop.

Again, any thoughts much appreciated. Thanks!

If it pulls 22 amps 3ph (assuming 8ish combined hp) it will be 22x1.732(single to 3ph conversion factor) so 38.104 amps from the panel.

You are overlooking the fact that single phase amperage and 3 phase amperage are not equal (hence the 1.732 multiplication factor when converting from 3ph motor plate to single phase input requirements.

[Erik Loza]

Kurt, I'm going to float this out there: Feel free to accept or reject as you like. I've been witness to this exact conversation with hobbyist ww'ers MANY times and it invariably goes one of two ways.

#1.) After running through all the mental gymnastics of what it would look like to actually acquire your ideal used machine (which often doesn't exist), and after running through all the mental gymnastics of getting a phase converter installed, the customer ends up back where they started and just buys a new 1-phase machine.

#2.) After running through all the mental gymnastics above, the customer decides it was just too much and ends up sticking with whatever smaller machines they have and never actually buy anything after all.

Not saying this is necessarily you, Kurt, just that I've seen the this scenario unfold many times in the past. Yes, there are some hobbyist owners here with three-phase machines and converters in their home shops and that's great but they would definitely be in the minority and more importantly, from a woodworking perspective, there is nothing you would be doing that a decent single-phase saw in the 4-5HP range couldn't accomplish. Your wallet and you should do what you want but from a buyer's standpoint, I think probably will find that by the time your search is over, it might even be cheaper to just get a 1-phase machine and be done with it so you can get on to actual woodworking. Again, just an opinion from a different perspective and good luck in your search.

Erik

[Jared Sankovich]

Kurt, I'm going to float this out there: Feel free to accept or reject as you like. I've been witness to this exact conversation with hobbyist ww'ers MANY times and it invariably goes one of two ways.

#1.) After running through all the mental gymnastics of what it would look like to actually acquire your ideal used machine (which often doesn't exist), and after running through all the mental gymnastics of getting a phase converter installed, the customer ends up back where they started and just buys a new 1-phase machine.

#2.) After running through all the mental gymnastics above, the customer decides it was just too much and ends up sticking with whatever smaller machines they have and never actually buy anything after all.

Not saying this is necessarily you, Kurt, just that I've seen the this scenario unfold many times in the past. Yes, there are some hobbyist owners here with three-phase machines and converters in their home shops and that's great but they would definitely be in the minority and more importantly, from a woodworking perspective, there is nothing you would be doing that a decent single-phase saw in the 4-5HP range couldn't accomplish. Your wallet and you should do what you want but from a buyer's standpoint, I think probably will find that by the time your search is over, it might even be cheaper to just get a 1-phase machine and be done with it so you can get on to actual woodworking. Again, just an opinion from a different perspective and good luck in your search.

Erik

I see the mental gymnastics is the common problem there.

So you didn't see a lot of people just buy stuff on a whim, drag it home and figure out how to make it work after the fact?

[Erik Loza]

So you didn't see a lot of people just buy stuff on a whim, drag it home and figure out how to make it work after the fact?

Nope.... The whole "Gee, I could score a sweet deal on a 3-phase machine?" exercise is like the Rumspringa of hobbyist woodworkers. Statistically speaking, most will come back to 1-phase. Not telling the OP what he should/ought to do, just sharing what my experience has been through the years.

Erik

[Phillip Mitchell]

This is a pretty easy problem to solve. I get that it’s unfamiliar at first and there are some questions / variables, but you’ve had a lot of solid and specific advice in this and other threads. Doesn’t need to be more complicated than necessary.

There are tons of used machines out there that will fit the bill and most are 3 phase within the category that you’re looking at. Finding a used single phase machine is much less likely, IMO. Based on the other thread, new and full stroke seems to be out of the budget.

There is an incredible amount of value in having the option to run 3 phase machines. I have outfitted my shop with (8) used 3 phase machines for roughly around the same cost of a full stroke well option premium Euro slider. I would likely not be woodworking if I thought I needed to buy machines new. Of course everyone should do what works for them, but if you are on a budget, trying to stretch it and want really high quality machines you would do well to familiarize yourself with the right phase converter setup for your needs and dig in.

[Kurt Wyberanec]

Kurt, I'm going to float this out there: Feel free to accept or reject as you like. I've been witness to this exact conversation with hobbyist ww'ers MANY times and it invariably goes one of two ways.

#1.) After running through all the mental gymnastics of what it would look like to actually acquire your ideal used machine (which often doesn't exist), and after running through all the mental gymnastics of getting a phase converter installed, the customer ends up back where they started and just buys a new 1-phase machine.

#2.) After running through all the mental gymnastics above, the customer decides it was just too much and ends up sticking with whatever smaller machines they have and never actually buy anything after all.

Not saying this is necessarily you, Kurt, just that I've seen the this scenario unfold many times in the past. Yes, there are some hobbyist owners here with three-phase machines and converters in their home shops and that's great but they would definitely be in the minority and more importantly, from a woodworking perspective, there is nothing you would be doing that a decent single-phase saw in the 4-5HP range couldn't accomplish. Your wallet and you should do what you want but from a buyer's standpoint, I think probably will find that by the time your search is over, it might even be cheaper to just get a 1-phase machine and be done with it so you can get on to actual woodworking. Again, just an opinion from a different perspective and good luck in your search.

Erik

This is a pretty easy problem to solve. I get that it’s unfamiliar at first and there are some questions / variables, but you’ve had a lot of solid and specific advice in this and other threads. Doesn’t need to be more complicated than necessary.

There are tons of used machines out there that will fit the bill and most are 3 phase within the category that you’re looking at. Finding a used single phase machine is much less likely, IMO. Based on the other thread, new and full stroke seems to be out of the budget.

There is an incredible amount of value in having the option to run 3 phase machines. I have outfitted my shop with (8) used 3 phase machines for roughly around the same cost of a full stroke well option premium Euro slider. I would likely not be woodworking if I thought I needed to buy machines new. Of course everyone should do what works for them, but if you are on a budget, trying to stretch it and want really high quality machines you would do well to familiarize yourself with the right phase converter setup for your needs and dig in.

Hey all, Erik, I definitely see the logic of what you're saying. And I can possibly see myself falling into scenario #1...I will be doing something so I won't just be falling back to what I have. That said, I'm one of those people who really wants to get the most out of their budget. I'm not afraid of used and I don't mind putting work and time in, but it all has to be worth it....in other words not just to save a few bucks because there are new machines that fall into the budget, but rather if I do go used, it's not going to be to lower the overall cost but rather to get something that is much more substantial than the new machine would be. It's like buying a luxury car....new lot of money, 5 years old often cheaper than a new Toyota if taken care of you still have the nice luxury car for a long time. A big part of me wants new but the big problem with things like this is that it's not like a car, because with a car I could just go to every dealership, see what I like and go for it, but saws are seemingly all going to be bought unseen or touched at least for me, so it's a big thought process.

Back to the topic at hand.....can anyone tell me what is wrong with the inexpensive static convertors? I just want to understand why I should be looking for either rotary or a PP over the others? Also, the rotary units seem to be significantly less efficient than say the PP but also cost significantly less. A saw that I'm currently looking at has a 9hp motor and the owner told me he uses a 20hp American Rotary and sent me the link and info and it works perfectly and easy to install. Now I don't know much more than that but 1500 new is a lot less than 2500+ for a 7.5 or 10 PP so trying to understand what the downsides are as best as possible.

Thanks again all!

[Phillip Mitchell]

It’s confusing because different manufacturers advertise and rate their units differently. Some companies advertise HP on the size of the idler motor itself (American Rotary) and not necessarily what size 3 ph motor it will start. Others (PP, Kay) advertise HP based on the largest size 3 ph motor it will start. You have to become familiar with the different companies and how they advertise and read the specs.

I’ll let someone else tackle the static converter question. It’s my understanding that you will only get up to 2/3 of the amps/HP out of your motor with that setup. I also thought it was for help starting the motor and then once it’s started you are only getting 2 out of the 3 legs of the the line power and hence not actually operating on true 3 phase, but I don’t have personal experience so not totally sure and the above may not be correct. Seems a poor choice for a nice slider with a big motor that you may want full capacity of.

[Kevin Jenness]

can anyone tell me what is wrong with the inexpensive static convertors?

Essentially, the motor is de-rated by 1/3. If you need the full power of the motor a static converter is a poor choice. A saw with a 9 hp motor would probably be fine, one with a 3 hp motor not so much. It depends on usage.

https://www.northamericaphaseconvert...onverter-faqs/

[Jared Sankovich]

Nope.... The whole "Gee, I could score a sweet deal on a 3-phase machine?" exercise is like the Rumspringa of hobbyist woodworkers. Statistically speaking, most will come back to 1-phase. Not telling the OP what he should/ought to do, just sharing what my experience has been through the years.

Erik

I was really surprised by that at first but the more I think about it thr more it actually makes sense. The owwm group and the have a machine comissioned group tend to be on opposite ends of the spectrum (as Hobbyists)

[roger wiegand]

I was really surprised by that at first but the more I think about it thr more it actually makes sense. The owwm group and the have a machine comissioned group tend to be on opposite ends of the spectrum (as Hobbyists)

Well, I just did the math. The nearly new, almost perfect, all the bells and whistles used 3 PH 16" J/P I found plus a RPC to run it was a couple thousand dollars cheaper than buying the same machine new. Of course, being cheap, I would have bought a lesser machine new. Having had it for a couple of years I'm really happy to have features like the motorized lift.

That said, I didn't think about adding a RPC to the shop until after I found the machine. Now, of course, I'm free to add other 3ph machines as I like.

[Carl Beckett]

can anyone tell me what is wrong with the inexpensive static convertors?

Essentially, the motor is de-rated by 1/3. If you need the full power of the motor a static converter is a poor choice. A saw with a 9 hp motor would probably be fine, one with a 3 hp motor not so much. It depends on usage.

https://www.northamericaphaseconvert...onverter-faqs/

Absolutely positively nothing wrong with the static converters. I ran a large belt sander on one for a few years with zero issues. I was never close to needing the full HP rating of the machine. It cost me $100 used off craigslist for the converter, and I sold it for what I paid for it once I installed a RPC (which I paid $500 for).

Static phase converters will work in many cases, especially hobbiest who are not taxing their machines to max HP.

Having said that, I agree with Erics comments.

[Kurt Wyberanec]

Absolutely positively nothing wrong with the static converters. I ran a large belt sander on one for a few years with zero issues. I was never close to needing the full HP rating of the machine. It cost me $100 used off craigslist for the converter, and I sold it for what I paid for it once I installed a RPC (which I paid $500 for).

Static phase converters will work in many cases, especially hobbiest who are not taxing their machines to max HP.

Having said that, I agree with Erics comments.

If I end up with about a 5hp saw then I could see myself getting close to taxing it only once in a while, say ripping 2" hardwood, but that's somewhat rare for me right now and currently am using a 3hp single phase. If it's 7.5 or great I doubt I will ever tax it.

On a different question is a Static convertor something you need to have an electrician install or is it something you can do yourself if slightly comfortable in your panel? 2nd, since they are less efficient do you need a bigger breaker for them, than say RPC or PP?

Thanks.

[Kevin Jenness]

My slot mortiser has a 3hp 3 phase motor. The static converter is a small box mounted on the machine and runs on a circuit with 12 ga wire and a 20 amp breaker. A single phase 3 hp motor typically draws about 17 amps @ 230 volts. I don't know that there is any loss of efficiency in using a static converter - perhaps one of the engineers here can comment.

I am not an electrician, and I didn't wire that converter, but I have wired up two VFDs and my rotary converter setup.

From the link I posted earlier

Mounting and Installation
Where can I install a static phase converter?
Generally it is mounted close to your equipment. It can be mounted directly to the equipment as long as there isn’t excessive vibration. A NAPCco static converter is equipped with two mounting brackets for easy installation.
Is a static phase converter easy to wire?
Absolutely, a NAPCco static phase converter has a simple three wire connection. A junction box is located on top of the converter’s enclosure wire a terminal block for wiring inside.
What size circuit breaker/fuse and wire do I use?
A circuit breaker switch and wire is determined by the size of the static phase converter and size of the motor you are starting. A recommended circuit breaker/fuse and wire chart is available in the operation and installation manual