|
Don’t need overly detailed info at this time but exploring some options.
For a 5.5 hp 3p table saw could a 10hp rp work or would i need to go to the next size which is i think 15hp.
Also would a vfd work and if so is there a way to wire it so the saw switches would work or is the only way to start is with the vfd. This saw would have a brake.
Regards, Mark
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Hi Mark, RPC supplier should be able to confirm. As you might know general rule of thumb is one needs an idle motor that is twice the size of load motor. The applications are divided into, IIRC, 3 classes of easy, moderate and hard. I believe a pump is in hard class so one should not push the RPC. Saw is either light or moderate so I think 10HP should work in general. VFD is too much pain to incorporate. RPC should last for ever, at most may need to change caps. I built one with 10HP salvage motor and it worked for 15+ yrs until I took it off line 2 yrs ago. Imran On Apr 15, 2020, at 9:34 PM, Mark Kessler <mkessler10@...> wrote:
?Don’t need overly detailed info at this time but exploring some options. For a 5.5 hp 3p table saw could a 10hp rp work or would i need to go to the next size which is i think 15hp. Also would a vfd work and if so is there a way to wire it so the saw switches would work or is the only way to start is with the vfd. This saw would have a brake. Regards, Mark
|
Your description is too vague to answer if a VFD is a good solution. The basic principle with a VFD is that you should not switch downstream of it, that is, don't put saw switches in between the VFD and the motor. A VFD is a motor-controller, not a power-generator (like a phase converter is)
But if the saw switches are just controlling a contactor that switches power to a motor, VFD conversion can be conceptually straightforward.
Like many things, there's an effort/cost tradeoff. If you price your own labor at $100/hr, buying a Phase Perfect is usually the cheapest solution.
|
Not sure why you think my description was too vague, not looking for a detailed response which you ended up answering perfectly just as Imran had done. Also what am I missing with the phase perfect being the cheapest solution, wouldn’t a regular ol’ rp be the cheapest? A 20hp rp is around $1100 And could be built for less if you had the motor, and pp starting around 3k Regards, Mark
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On Apr 16, 2020, at 1:17 AM, mark thomas <murkyd@...> wrote:
?Your description is too vague to answer if a VFD is a good solution. The basic principle with a VFD is that you should not switch downstream of it, that is, don't put saw switches in between the VFD and the motor. A VFD is a motor-controller, not a power-generator (like a phase converter is)
But if the saw switches are just controlling a contactor that switches power to a motor, VFD conversion can be conceptually straightforward.
Like many things, there's an effort/cost tradeoff. If you price your own labor at $100/hr, buying a Phase Perfect is usually the cheapest solution.
|
Mark,
This has been discussed here often. Biggest diff between RPC and phase perfect solution is the voltage regulation. I guess PP is more efficient and low noise as well.
Unlike VFD, both can run multiple machines but modern machines with electronics can be damaged with RPC if they are exposed to the higher voltage of the manufactured leg.
Now this has been the majority opinion on RPC but as a person who has built and used one, there are ways to ensure that manufactured leg only goes to the motor. This is usually possible but needs to be ensured with each machine.
In my mind, biggest issue with RPC is with warranty. If you are buying a new machine with electronics and you end up having an electrical issue the machine manufacturer could hold the use of RPC against you.
Hope this helps.
Imran
On Apr 16, 2020, at 7:15 AM, Mark Kessler <mkessler10@...> wrote:
? Not sure why you think my description was too vague, not looking for a detailed response which you ended up answering perfectly just as Imran had done. Also what am I missing with the phase perfect being the cheapest solution, wouldn’t a regular ol’ rp be the cheapest? A 20hp rp is around $1100 And could be built for less if you had the motor, and pp starting around 3k Regards, Mark On Apr 16, 2020, at 1:17 AM, mark thomas <murkyd@...> wrote:
?Your description is too vague to answer if a VFD is a good solution. The basic principle with a VFD is that you should not switch downstream of it, that is, don't put saw switches in between the VFD and the motor. A VFD is a motor-controller, not a power-generator (like a phase converter is)
But if the saw switches are just controlling a contactor that switches power to a motor, VFD conversion can be conceptually straightforward.
Like many things, there's an effort/cost tradeoff. If you price your own labor at $100/hr, buying a Phase Perfect is usually the cheapest solution.
|
Thanks Imran, This is good to know, I wouldn’t have bothered asking if I wasn’t stuck home working - after all I do work in an electrical lab with access to electrical engineers.
So basically an PP would be preferable but an RPC would work making sure the manufactured leg goes only to the motor, assuming that is done is there any concern an RPC could damage a machine with electronics?
toggle quoted message
Show quoted text
On Apr 16, 2020, at 7:47 AM, imranindiana via groups.io <imranindiana@...> wrote:
? Mark,
This has been discussed here often. Biggest diff between RPC and phase perfect solution is the voltage regulation. I guess PP is more efficient and low noise as well.
Unlike VFD, both can run multiple machines but modern machines with electronics can be damaged with RPC if they are exposed to the higher voltage of the manufactured leg.
Now this has been the majority opinion on RPC but as a person who has built and used one, there are ways to ensure that manufactured leg only goes to the motor. This is usually possible but needs to be ensured with each machine.
In my mind, biggest issue with RPC is with warranty. If you are buying a new machine with electronics and you end up having an electrical issue the machine manufacturer could hold the use of RPC against you.
Hope this helps.
Imran
On Apr 16, 2020, at 7:15 AM, Mark Kessler <mkessler10@...> wrote:
? Not sure why you think my description was too vague, not looking for a detailed response which you ended up answering perfectly just as Imran had done. Also what am I missing with the phase perfect being the cheapest solution, wouldn’t a regular ol’ rp be the cheapest? A 20hp rp is around $1100 And could be built for less if you had the motor, and pp starting around 3k Regards, Mark On Apr 16, 2020, at 1:17 AM, mark thomas <murkyd@...> wrote:
?Your description is too vague to answer if a VFD is a good solution. The basic principle with a VFD is that you should not switch downstream of it, that is, don't put saw switches in between the VFD and the motor. A VFD is a motor-controller, not a power-generator (like a phase converter is)
But if the saw switches are just controlling a contactor that switches power to a motor, VFD conversion can be conceptually straightforward.
Like many things, there's an effort/cost tradeoff. If you price your own labor at $100/hr, buying a Phase Perfect is usually the cheapest solution.
|
Mark, ? PP is the gold standard but take a look and give the folks a call at American Rotary about their RPCs.? Their voltage generation tolerances are pretty tight. Dave Davies
Thanks Imran, This is good to know, I wouldn’t have bothered asking if I wasn’t stuck home working - after all I do work in an electrical lab with access to electrical engineers.
So basically an PP would be preferable but an RPC would work making sure the manufactured leg goes only to the motor, assuming that is done is there any concern an RPC could damage a machine with electronics? Regards, Mark On Apr 16, 2020, at 7:47 AM, imranindiana via <imranindiana=[email protected]> wrote:
? Mark,
This has been discussed here often. Biggest diff between RPC and phase perfect solution is the voltage regulation. I guess PP is more efficient and low noise as well.
Unlike VFD, both can run multiple machines but modern machines with electronics can be damaged with RPC if they are exposed to the higher voltage of the manufactured leg.
Now this has been the majority opinion on RPC but as a person who has built and used one, there are ways to ensure that manufactured leg only goes to the motor. This is usually possible but needs to be ensured with each machine.
In my mind, biggest issue with RPC is with warranty. If you are buying a new machine with electronics and you end up having an electrical issue the machine manufacturer could hold the use of RPC against you.
Hope this helps.
Imran
?Not sure why you think my description was too vague, not looking for a detailed response which you ended up answering perfectly just as Imran had done. Also what am I missing with the phase perfect being the cheapest solution, wouldn’t a regular ol’ rp be the cheapest? A 20hp rp is around $1100 And could be built for less if you had the motor, and pp starting around 3k Regards, Mark On Apr 16, 2020, at 1:17 AM, mark thomas <murkyd@...> wrote:
?Your description is too vague to answer if a VFD is a good solution. The basic principle with a VFD is that you should not switch downstream of it, that is, don't put saw switches in between the VFD and the motor. A VFD is a motor-controller, not a power-generator (like a phase converter is)
But if the saw switches are just controlling a contactor that switches power to a motor, VFD conversion can be conceptually straightforward.
Like many things, there's an effort/cost tradeoff. If you price your own labor at $100/hr, buying a Phase Perfect is usually the cheapest solution.
-- Dave & Marie Davies
318-219-7868
|
Mark,
Many would disagree but personally if I had to I will run machines on RPC making sure manufactured leg only goes to the motor (hopefully machine design allows for that). I will check all 3 phases with major machine combos running to ensure all voltages are in spec. IIRC, Felder had 253V as max on motor and my RPC produced no more.
I have mine mothballed in case PP croaks but I will need a bigger idle motor since my biggest machine now is 10 HP. I have plans if you want to build one. I paid $30 for salvage 3ph 10HP Motor and $75 for the used contactor. These are the 2 major components.
Imran On Apr 16, 2020, at 8:20 AM, Mark Kessler <mkessler10@...> wrote:
? Thanks Imran, This is good to know, I wouldn’t have bothered asking if I wasn’t stuck home working - after all I do work in an electrical lab with access to electrical engineers.
So basically an PP would be preferable but an RPC would work making sure the manufactured leg goes only to the motor, assuming that is done is there any concern an RPC could damage a machine with electronics? Regards, Mark On Apr 16, 2020, at 7:47 AM, imranindiana via groups.io <imranindiana@...> wrote:
? Mark,
This has been discussed here often. Biggest diff between RPC and phase perfect solution is the voltage regulation. I guess PP is more efficient and low noise as well.
Unlike VFD, both can run multiple machines but modern machines with electronics can be damaged with RPC if they are exposed to the higher voltage of the manufactured leg.
Now this has been the majority opinion on RPC but as a person who has built and used one, there are ways to ensure that manufactured leg only goes to the motor. This is usually possible but needs to be ensured with each machine.
In my mind, biggest issue with RPC is with warranty. If you are buying a new machine with electronics and you end up having an electrical issue the machine manufacturer could hold the use of RPC against you.
Hope this helps.
Imran
On Apr 16, 2020, at 7:15 AM, Mark Kessler <mkessler10@...> wrote:
? Not sure why you think my description was too vague, not looking for a detailed response which you ended up answering perfectly just as Imran had done. Also what am I missing with the phase perfect being the cheapest solution, wouldn’t a regular ol’ rp be the cheapest? A 20hp rp is around $1100 And could be built for less if you had the motor, and pp starting around 3k Regards, Mark On Apr 16, 2020, at 1:17 AM, mark thomas <murkyd@...> wrote:
?Your description is too vague to answer if a VFD is a good solution. The basic principle with a VFD is that you should not switch downstream of it, that is, don't put saw switches in between the VFD and the motor. A VFD is a motor-controller, not a power-generator (like a phase converter is)
But if the saw switches are just controlling a contactor that switches power to a motor, VFD conversion can be conceptually straightforward.
Like many things, there's an effort/cost tradeoff. If you price your own labor at $100/hr, buying a Phase Perfect is usually the cheapest solution.
|
I just meant too vague for a specific answer, in that the effort to adapt a VFD varies with the complexity of the specific machine.? Fwiw, I don't think Imran and I answered the question the same.? He said VFD is "too much pain".? I'm saying zero pain to a lot of pain, depending on the (unknown) specifics.
Re Phase Perfect, I meant in the long-term, evolving to multiple machines, etc.? For a single machine, off-the-shelf rotary is cheaper and probably more logical.? ?For example, ~20 years ago I got a Phase Perfect.? It took an hour to install.? I've never spent another minute on my 3P power.? On the other hand, I've seen lots of people start with a small home-built rotary (typically tens of hours to build), find they have to "tune" it periodically as machines change, later add a second one, etc. and sometimes, end up later buying a Phase Perfect.? ? So I'm just saying if you look ahead a decade or so, the Phase Perfect can look pretty attractive for its simplicity, reliability, flexibility, power quality, etc.
Also, to clarify/elaborate, I'm not really making a strict bean-counting argument.? It's also metaphor about priorities.? If building a RP is a fun/interesting project and the time spent is valuable relative to other things one can do with their time, and the dollar savings are not insignificant to a person, it's a super great solution.? ?At the other end of the spectrum, if it's an undesirable-but-tolerable chore to save money, the calculus is different.
It's common that people look back 10, 20, 30 years and?with hindsight conclude that investing more/earlier would have been a better strategy than what they did at the time driven by shorter-horizon thinking, because over the long haul the aggregate investment of churning thru iterations is more costly.? As tool fans often say, "cry once".? (Of course, just because it's a "good strategy" doesn't mean it's necessarily actually doable/affordable, etc)? ?
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FWIW, I agree with Mark Thomas msg below. I am a curious person and loved building the RPC. I built a 3 phase distribution center so replacing RPC with PP was easy. Even use the same wall switch (with new 250V instead of 110V switch) to turn PP on/off. ? Imran ?
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From: [email protected] On Behalf Of mark thomas Sent: Thursday, April 16, 2020 8:50 AM To: [email protected]Subject: Re: [FOG] Phase converter questions ? I just meant too vague for a specific answer, in that the effort to adapt a VFD varies with the complexity of the specific machine.? Fwiw, I don't think Imran and I answered the question the same.? He said VFD is "too much pain".? I'm saying zero pain to a lot of pain, depending on the (unknown) specifics.
Re Phase Perfect, I meant in the long-term, evolving to multiple machines, etc.? For a single machine, off-the-shelf rotary is cheaper and probably more logical.? ?For example, ~20 years ago I got a Phase Perfect.? It took an hour to install.? I've never spent another minute on my 3P power.? On the other hand, I've seen lots of people start with a small home-built rotary (typically tens of hours to build), find they have to "tune" it periodically as machines change, later add a second one, etc. and sometimes, end up later buying a Phase Perfect.? ? So I'm just saying if you look ahead a decade or so, the Phase Perfect can look pretty attractive for its simplicity, reliability, flexibility, power quality, etc.
Also, to clarify/elaborate, I'm not really making a strict bean-counting argument.? It's also metaphor about priorities.? If building a RP is a fun/interesting project and the time spent is valuable relative to other things one can do with their time, and the dollar savings are not insignificant to a person, it's a super great solution.? ?At the other end of the spectrum, if it's an undesirable-but-tolerable chore to save money, the calculus is different.
It's common that people look back 10, 20, 30 years and?with hindsight conclude that investing more/earlier would have been a better strategy than what they did at the time driven by shorter-horizon thinking, because over the long haul the aggregate investment of churning thru iterations is more costly.? As tool fans often say, "cry once".? (Of course, just because it's a "good strategy" doesn't mean it's necessarily actually doable/affordable, etc)? ?
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And why did you replace RPC with PP?? ?Capacity increase?
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Yes, Dual51 is 10HP and it came with PP.
Imran On Apr 16, 2020, at 9:18 AM, mark thomas <murkyd@...> wrote:
?And why did you replace RPC with PP?? ?Capacity increase?
|
I've both and a balanced RPC can do a good job if the variation in motor sizes it is running isn't too great, which shouldn't be the case if 5.5 hp is the largest you intend to run.? Kay and Arco size their units by the largest hard starting motor it will handle.?
Most others, including Am Rotary, size theirs by the total output so you generally need to double.? I would not be afraid to run a 10 hp AR with a 5.5 hp motor.? The exception might be a big old bandsaw with a 6 or 8 pole 5 hp motor.? The PP is a step above
but rpc can be found or built pretty cheap.? Dave
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Thanks Imran,
This is good to know, I wouldn’t have bothered asking if I wasn’t stuck home working - after all I do work in an electrical lab with access to electrical engineers.
So basically an PP would be preferable but an RPC would work making sure the manufactured leg goes only to the motor, assuming that is done is there any concern an RPC could damage a machine with electronics?
Regards, Mark
On Apr 16, 2020, at 7:47 AM, imranindiana via groups.io <imranindiana@...> wrote:
?
Mark,
This has been discussed here often. Biggest diff between RPC and phase perfect solution is the voltage regulation. I guess PP is more efficient and low noise as well.
Unlike VFD, both can run multiple machines but modern machines with electronics can be damaged with RPC if they are exposed to the higher voltage of the manufactured leg.
Now this has been the majority opinion on RPC but as a person who has built and used one, there are ways to ensure that manufactured leg only goes to the motor. This is usually possible but needs to be ensured with each machine.
In my mind, biggest issue with RPC is with warranty. If you are buying a new machine with electronics and you end up having an electrical issue the machine manufacturer could hold the use of RPC against you.
Hope this helps.
Imran
On Apr 16, 2020, at 7:15 AM, Mark Kessler <mkessler10@...> wrote:
?Not sure why you think my description was too vague, not looking for a detailed response which you ended up answering perfectly just as Imran had done. Also what am I missing with the phase perfect being the cheapest solution, wouldn’t a regular
ol’ rp be the cheapest? A 20hp rp is around $1100 And could be built for less if you had the motor, and pp starting around 3k
Regards, Mark
On Apr 16, 2020, at 1:17 AM, mark thomas <murkyd@...> wrote:
?Your description is too vague to answer if a VFD is a good solution. The basic principle with a VFD is that you should not switch downstream of it, that is, don't put saw switches in between the VFD and the
motor. A VFD is a motor-controller, not a power-generator (like a phase converter is)
But if the saw switches are just controlling a contactor that switches power to a motor, VFD conversion can be conceptually straightforward.
Like many things, there's an effort/cost tradeoff. If you price your own labor at $100/hr, buying a Phase Perfect is usually the cheapest solution.
|
Hey Mark, I use a 10hp kay rpc for 2 of my felder machines, both have 5.5hp motors (one has 2 kf700s) but anyways, its super easy to wire and works wonderfully.?
|
Yes a 10hp RPC will work. And yes, a VFD works just fine and you can wire the VFD to use the saw switches to turn it on and off, it’s easy. As for the brake, not needed with the VFD, it does the braking.
Brian Lamb
blamb11@...
www.lambtoolworks.com
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On Apr 15, 2020, at 6:34 PM, Mark Kessler <mkessler10@...> wrote:
Don’t need overly detailed info at this time but exploring some options.
For a 5.5 hp 3p table saw could a 10hp rp work or would i need to go to the next size which is i think 15hp.
Also would a vfd work and if so is there a way to wire it so the saw switches would work or is the only way to start is with the vfd. This saw would have a brake.
Regards, Mark
|
Brian, I did not go into the details but if VFD is used then it can (probably should) be used to brake as you are suggesting but I would disconnect the electric brake on the machine as there could be some interactions. Electric brake circuits on the machine will be loosing power while trying to brake. VFD may also need external brake resistors. Imran On Apr 16, 2020, at 11:02 AM, Brian Lamb <blamb11@...> wrote:
?Yes a 10hp RPC will work. And yes, a VFD works just fine and you can wire the VFD to use the saw switches to turn it on and off, it’s easy. As for the brake, not needed with the VFD, it does the braking. Brian Lamb blamb11@... www.lambtoolworks.com On Apr 15, 2020, at 6:34 PM, Mark Kessler <mkessler10@...> wrote:
Don’t need overly detailed info at this time but exploring some options.
For a 5.5 hp 3p table saw could a 10hp rp work or would i need to go to the next size which is i think 15hp.
Also would a vfd work and if so is there a way to wire it so the saw switches would work or is the only way to start is with the vfd. This saw would have a brake.
Regards, Mark
|
Thanks everyone for the excellent responses, sounds like i have options be it VFD, RPC or PP. Will revisit this post for more q&a if things workout.
Regards, Mark
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On Apr 16, 2020, at 12:16 PM, imranindiana via groups.io <imranindiana@...> wrote:
?Brian,
I did not go into the details but if VFD is used then it can (probably should) be used to brake as you are suggesting but I would disconnect the electric brake on the machine as there could be some interactions. Electric brake circuits on the machine will be loosing power while trying to brake.
VFD may also need external brake resistors.
Imran
On Apr 16, 2020, at 11:02 AM, Brian Lamb <blamb11@...> wrote:
?Yes a 10hp RPC will work. And yes, a VFD works just fine and you can wire the VFD to use the saw switches to turn it on and off, it’s easy. As for the brake, not needed with the VFD, it does the braking.
Brian Lamb
blamb11@...
www.lambtoolworks.com
On Apr 15, 2020, at 6:34 PM, Mark Kessler <mkessler10@...> wrote:
Don’t need overly detailed info at this time but exploring some options.
For a 5.5 hp 3p table saw could a 10hp rp work or would i need to go to the next size which is i think 15hp.
Also would a vfd work and if so is there a way to wire it so the saw switches would work or is the only way to start is with the vfd. This saw would have a brake.
Regards, Mark
|
I second DD’s recommendation of American Rotary. My AR rpc runs my 10hp Dual 51 great. No voltage issues whatsoever.?
I would have no hesitation to run a new 3ph machine with “electronics” off my rpc.?
I concede that PP is the more elegant solution.?
David Shores
On Thu, Apr 16, 2020 at 08:26 AM, David Davies wrote:
Mark,
? PP is the gold standard but take a look and give the folks a call at American Rotary about their RPCs.? Their voltage generation tolerances are pretty tight.
Dave Davies
Thanks Imran,
This is good to know, I wouldn’t have bothered asking if I wasn’t stuck home working - after all I do work in an electrical lab with access to electrical engineers.
?
So basically an PP would be preferable but an RPC would work making sure the manufactured leg goes only to the motor, assuming that is done is there any concern an RPC could damage a machine with electronics?
Regards, Mark
On Apr 16, 2020, at 7:47 AM, imranindiana via <imranindiana=[email protected]> wrote:
Mark,
?
This has been discussed here often. Biggest diff between RPC and phase perfect solution is the voltage regulation. I guess PP is more efficient and low noise as well.
?
Unlike VFD, both can run multiple machines but modern machines with electronics can be damaged with RPC if they are exposed to the higher voltage of the manufactured leg.
?
Now this has been the majority opinion on RPC but as a person who has built and used one, there are ways to ensure that manufactured leg only goes to the motor. This is usually possible but needs to be ensured with each machine.
?
In my mind, biggest issue with RPC is with warranty. If you are buying a new machine with electronics and you end up having an electrical issue the machine manufacturer could hold the use of RPC against you.
?
Hope this helps.
?
Imran
?
Not sure why you think my description was too vague, not looking for a detailed response which you ended up answering perfectly just as Imran had done. Also what am I missing with the phase perfect being the cheapest solution, wouldn’t a regular ol’ rp be the cheapest? A 20hp rp is around $1100 And could be built for less if you had the motor, and pp starting around 3k
Regards, Mark
On Apr 16, 2020, at 1:17 AM, mark thomas <murkyd@...> wrote:
Your description is too vague to answer if a VFD is a good solution. The basic principle with a VFD is that you should not switch downstream of it, that is, don't put saw switches in between the VFD and the motor. A VFD is a motor-controller, not a power-generator (like a phase converter is)
But if the saw switches are just controlling a contactor that switches power to a motor, VFD conversion can be conceptually straightforward.
Like many things, there's an effort/cost tradeoff. If you price your own labor at $100/hr, buying a Phase Perfect is usually the cheapest solution.
?
?
?
--
Dave & Marie Davies
318-219-7868
|
For anyone interested in a Phase Perfect convertor I have one that ran my K915 back in Maine. It will be for sale when I get back there this summer. In Arizona now for winter. The folks who bought the saw didn’t need it. A fair price, whatever that is....
Bill Belanger?
On Thu, Apr 16, 2020 at 10:54 David Shores < dgshores@...> wrote: I second DD’s recommendation of American Rotary. My AR rpc runs my 10hp Dual 51 great. No voltage issues whatsoever.?
I would have no hesitation to run a new 3ph machine with “electronics” off my rpc.?
I concede that PP is the more elegant solution.?
David Shores
On Thu, Apr 16, 2020 at 08:26 AM, David Davies wrote:
Mark,
? PP is the gold standard but take a look and give the folks a call at American Rotary about their RPCs.? Their voltage generation tolerances are pretty tight.
Dave Davies
Thanks Imran,
This is good to know, I wouldn’t have bothered asking if I wasn’t stuck home working - after all I do work in an electrical lab with access to electrical engineers.
?
So basically an PP would be preferable but an RPC would work making sure the manufactured leg goes only to the motor, assuming that is done is there any concern an RPC could damage a machine with electronics?
Regards, Mark
On Apr 16, 2020, at 7:47 AM, imranindiana via <imranindiana=[email protected]> wrote:
Mark,
?
This has been discussed here often. Biggest diff between RPC and phase perfect solution is the voltage regulation. I guess PP is more efficient and low noise as well.
?
Unlike VFD, both can run multiple machines but modern machines with electronics can be damaged with RPC if they are exposed to the higher voltage of the manufactured leg.
?
Now this has been the majority opinion on RPC but as a person who has built and used one, there are ways to ensure that manufactured leg only goes to the motor. This is usually possible but needs to be ensured with each machine.
?
In my mind, biggest issue with RPC is with warranty. If you are buying a new machine with electronics and you end up having an electrical issue the machine manufacturer could hold the use of RPC against you.
?
Hope this helps.
?
Imran
?
Not sure why you think my description was too vague, not looking for a detailed response which you ended up answering perfectly just as Imran had done. Also what am I missing with the phase perfect being the cheapest solution, wouldn’t a regular ol’ rp be the cheapest? A 20hp rp is around $1100 And could be built for less if you had the motor, and pp starting around 3k
Regards, Mark
On Apr 16, 2020, at 1:17 AM, mark thomas <murkyd@...> wrote:
Your description is too vague to answer if a VFD is a good solution. The basic principle with a VFD is that you should not switch downstream of it, that is, don't put saw switches in between the VFD and the motor. A VFD is a motor-controller, not a power-generator (like a phase converter is)
But if the saw switches are just controlling a contactor that switches power to a motor, VFD conversion can be conceptually straightforward.
Like many things, there's an effort/cost tradeoff. If you price your own labor at $100/hr, buying a Phase Perfect is usually the cheapest solution.
?
?
?
--
Dave & Marie Davies
318-219-7868
|
Have a look at this post for info on my N4400 VFD conversion. It's not difficult - and if you have access to those electrical engineers it should be even easier, if your motor is suitable (and not all 3P's are). You do need to check this carefully, and do a bit of research. Beware that there is a fair amount of misunderstanding and misinformation about these things on the interwebs, which unfortunately doesn't stop every man and his dog weighing in with their ill-guided opinion. The other option, which I know you didn't ask about, but is provided free, gratis and for nothing (!), is to consider replacing the 3P motor with a similarly powered 1P motor. Felder may have options, but they will be the usual eye-watering price, but any decent motor supplier should be able to advise and find you something with the correct mounting plate and shaft size.
|
imran
Bill Belanger
Bernard