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Trying to build static phase converter for harrison m400 10hp late motor

workshoprat

Plastic
Joined
Dec 8, 2012
Location
Bois D Arc MO
Hey guys im trying to do a static phase converter for a harrison m400 10 hp lathe motor. I am having great trouble getting this to a usable configuration. Its easy enough to use start and run capacitors to start and run the motor. It is clutched so it starts in freewheel mode not much of a starting load. I can get it where all legs are balanced within about 4 volts of each other when running. I have a magnetic relay and can get it to work as an auto start to kick out the start caps when it gets up to speed with a 600 ohm resistor in line.

First problem. The coil on my relay draws enough current it will blow out a 500 ohm 5 watt resistor in a short amount of time. It has a 120v coil. Im pretty sure i need a 220v coil relay. Its hard as heck to find an affordable 220v coil relay with nc contacts large enough to handle the amp load of the caps and motor draw.

Second problem is that when a load is applied its enough to throw everything out of phase and stall the motor. It seems running free wheel and under load are two different things lol. I can add more run capacitors to where this is lessened but the more i add the worse the leg voltage balance gets and causes other issues.

I have never had a phase converter design fight me this bad. Of course the largest motor i have tried this on up untill now was a 2 hp motor.seems once you get up to the 10hp range everything changes and its a whole different ball game.

Do you think it would make a difference if the motor is wired in a wye or delta pattern for this application?
 
You are trying to re-invent the wheel and learning why static converters are not preferred. My two cents, quit beating your head into a brick wall and get an idler motor to build a conventional RPC. Plenty of proven designs out there.

An inexpensive 220 volt coil relay with larger contacts is a motor contactor. 1 and 2 hp sizes go for peanuts used.
 
You are trying to re-invent the wheel and learning why static converters are not preferred. My two cents, quit beating your head into a brick wall and get an idler motor to build a conventional RPC. Plenty of proven designs out there.

An inexpensive 220 volt coil relay with larger contacts is a motor contactor. 1 and 2 hp sizes go for peanuts used.

yea I may have to go that route. I really want to avoid that if at all possible. I have had rpc before and really they are another lump of crap to take up room in the shop. plus the added noise. then it also makes running the lathe more of a process than just pushing the button and go. Plus for a 10 hp motor you would need a about a 12-15 hp idler motor. thats a huge added expense. if it were 1-2 hp no big deal lol. anyhow not opposed to it just would preffer not to if avoidable.
 
also i already have a motor contactor im using for the relay. only prop i think is that its a 110v coil. Not sure if i need the 220v coil or not. It seems they are hard to find with NC contacts. Biggest problem is shopping online you cant hold it in your hand and inspect it. your relying on crappy pictures and half arsed descriptions from people who dont even know what it is let alone how to describe it. local supply is non exsistent lol!!!
 
First problem. The coil on my relay draws enough current it will blow out a 500 ohm 5 watt resistor in a short amount of time. It has a 120v coil. Im pretty sure i need a 220v coil relay. Its hard as heck to find an affordable 220v coil relay with nc contacts large enough to handle the amp load of the caps and motor draw.

Second problem is that when a load is applied its enough to throw everything out of phase and stall the motor. It seems running free wheel and under load are two different things lol. I can add more run capacitors to where this is lessened but the more i add the worse the leg voltage balance gets and causes other issues.

QUOTE]

1) What is the resistance of the coil? My calculations say if you have 110 V on the coil, then you have 110 V on the resistor and the resistor is dissipating 24.2W, so yeah it will smoke in short order. If you wan the resistor to last you need twice the applied load or a 50W rated part.

2) what is the line to line voltage? I run 5 HP on a static no problem. The world is linear, 10 HP takes 2x the current, but should run fine.

CarlBoyd
 
Its standard 220v houshold line voltage. Id have to measure to get the exact voltage. Of course that varies from day to day hour to hour.

On the coil resistance I don't really recall I'd have to measure I have so many numbers stuck in my head for measuring so many different coils I'd hate to lie to you without measuring it
 
Also on the voltage to the coil I am not sure as to what the voltage it is getting. For some reason I'm having a hard time getting a reading of what the voltage is. It's really difficult to measure as it has to be running in your measuring the voltage between the legs. When I let measure between the legs on the contactor while it is running I get anywhere from 246 to 250 volts. For some reason it won't read voltage at the coil.
 
After some more reasearch i am starting to think my issue may be the y or delta configuration issue. After work tonight i will try to get the cover off the motor and see how it is set up. The tag looks like it says it can be set up y or delta so should have 6 leads. If its set up for y that definatly cause tje low torque issue im having!

Why Wye? Why Delta?
 
Why would you want a static converter considering the 1/3 loss of motor hp? I agree on the rpc pia and noise, look up the book "Unique 3 phase", it is actually an older way to get 3 ph, it uses a transformer instead of an idler motor. There is a long thread somewhere on this site with some info on doing it. I have no first hand experience with it, but am contemplating building one for my new shop so I don't have the rpc drone in it.
 
Why would you want a static converter considering the 1/3 loss of motor hp? I agree on the rpc pia and noise, look up the book "Unique 3 phase", it is actually an older way to get 3 ph, it uses a transformer instead of an idler motor. There is a long thread somewhere on this site with some info on doing it. I have no first hand experience with it, but am contemplating building one for my new shop so I don't have the rpc drone in it.

Well on most of the stuff i have converted this way i did not have a bad enough loss if power to notice. I was thinking a 16" swing lathe was overkilled to begin with with a 10hp motor and was hoping it would not be an issue. I will have to look at that transformer method!
 
First problem. The coil on my relay draws enough current it will blow out a 500 ohm 5 watt resistor in a short amount of time. It has a 120v coil. Im pretty sure i need a 220v coil relay. Its hard as heck to find an affordable 220v coil relay with nc contacts large enough to handle the amp load of the caps and motor draw.

Second problem is that when a load is applied its enough to throw everything out of phase and stall the motor. It seems running free wheel and under load are two different things lol. I can add more run capacitors to where this is lessened but the more i add the worse the leg voltage balance gets and causes other issues.

QUOTE]

1) What is the resistance of the coil? My calculations say if you have 110 V on the coil, then you have 110 V on the resistor and the resistor is dissipating 24.2W, so yeah it will smoke in short order. If you wan the resistor to last you need twice the applied load or a 50W rated part.

2) what is the line to line voltage? I run 5 HP on a static no problem. The world is linear, 10 HP takes 2x the current, but should run fine.

CarlBoyd

Carl the resistance on tbe coil is 106.8 ohms. Just wondering how you figured 50 watts. If you dont mind could you post the math on that? Its been a long time since i did that in school and cant recal how! Lol its a bitch getting old lol!
 
Well i got out to the shop when i got home and much to my dismay it is configured for delta. There goes my wired for y theory out the window and leaves me in the unfortunate position of still scratching my head lol!

20180409_171320.jpg
 
yea I may have to go that route. I really want to avoid that if at all possible. I have had rpc before and really they are another lump of crap to take up room in the shop. plus the added noise. then it also makes running the lathe more of a process than just pushing the button and go. Plus for a 10 hp motor you would need a about a 12-15 hp idler motor. thats a huge added expense. if it were 1-2 hp no big deal lol. anyhow not opposed to it just would preffer not to if avoidable.

Well. YES.

One DOES need an RPC idler of about fifty-percent higher HP rating than the largest of the several load motors it will be asked to start as well as run (perhaps at very much lighter load than full-gallop, but RPC's are au fait with that).

Seems you have grokked that already? Yes.

Now .. just WTF sort of "magic" do you expect a static so-CALLED "converter", which isn't, really, a converter AT ALL - merely an enclosure of trickery meant to entice the load motor to get off its ass and run crippled on "dropped phase" at around 30% power.. to do WITHOUT the aid of that rotary-transformer function the idler provides?

And for a spindle-driven at as much as TEN HP, not 1/4 HP to 2 HP as for a coolant-pump?

RPC's provide as much as 91% of OEM "nameplate" HP at the load, or any lesser amount called for.

Static provides for about 31% of rated HP, and are more critical as to balance under load changes.

Only advantage to a static - if even there is ANY advantage - is at wintertimes.

More heat than motion from the poor abused motor, less need of shop heaters.
Spring is coming. Then summer. Less advantage to waste heat.

Harrison's are too nice a lathe to beat-up-on that way as well.

Money ahead to use an RPC.

Year-round, even.

Too "noisy"? Just exile the sumbich to your back garden bomb-shelter or a dog-house.
 
Well. YES.

One DOES need an RPC idler of about fifty-percent higher HP rating than the largest of the several load motors it will be asked to start as well as run (perhaps at very much lighter load than full-gallop, but RPC's are au fait with that).

Seems you have grokked that already? Yes.

Now .. just WTF sort of "magic" do you expect a static so-CALLED "converter", which isn't, really, a converter AT ALL - merely an enclosure of trickery meant to entice the load motor to get off its ass and run crippled on "dropped phase" at around 30% power.. to do WITHOUT the aid of that rotary-transformer function the idler provides?

And for a spindle-driven at as much as TEN HP, not 1/4 HP to 2 HP as for a coolant-pump?

RPC's provide as much as 91% of OEM "nameplate" HP at the load, or any lesser amount called for.

Static provides for about 31% of rated HP, and are more critical as to balance under load changes.

Only advantage to a static - if even there is ANY advantage - is at wintertimes.

More heat than motion from the poor abused motor, less need of shop heaters.
Spring is coming. Then summer. Less advantage to waste heat.

Harrison's are too nice a lathe to beat-up-on that way as well.

Money ahead to use an RPC.

Year-round, even.

Too "noisy"? Just exile the sumbich to your back garden bomb-shelter or a dog-house.

Well right and if im gona drop a huge sum of cash fod a 15hp 3ph motor to make a rpc then at what point would i just be better off and buy a 1ph 10 hp motor and be done with it? Heck i mean as long as were just throwing buckets of money around why dont i just go buy a million dollar shop in the city with good 3 phase service then pay out the ass for a monthly minimun for a machine im gona use once in a while on a hobby level? Heck its only money right?
 
Well right and if im gona drop a huge sum of cash fod a 15hp 3ph motor to make a rpc then at what point would i just be better off and buy a 1ph 10 hp motor and be done with it? Heck i mean as long as were just throwing buckets of money around why dont i just go buy a million dollar shop in the city with good 3 phase service then pay out the ass for a monthly minimun for a machine im gona use once in a while on a hobby level? Heck its only money right?

?? It is "only money".. but pissed down a rathole if "Static Converter' and TEN Mike-Foxtrot HP are in the same thread. Starting a 10 HP motor is demanding even if runnign it is less-so.

There's a 7 to 10 HP rated commercial static unit laying about right here that I took OFF my Cazeneuve 7 HP HBX-360-BC as a seriously bad joke. Best news is that it had crippled the poor French girl so badly and for so long she has very little WEAR!

Ten HP Weg ODP idler motor, brand-new, Brazilian, not Chinese (and the Weg clan were German immigrants, even so, BTW) shipped and liftgated here was right around $400. You already HAVE what you need in the "static" parts project to start and run such a critter.

USED 3-Phase motors for idlers can be had from free, through $50-$200 ELSE keep looking.

Single phase it? Well.. you were only going to have a best-case 3.1 HP with a static converter anyway, so a 5 HP single-phase motor could actually be an improvement, and will also run cooler, and even smoother, than a bef**ked 3-P would have done on dropped-phase.

The best advice PM has doesn't cause utility-mains grade 3-P nor cash money to fall out of the sky, no.

It surely can help you waste less of what you DO have.
 
?? It is "only money".. but pissed down a rathole if "Static Converter' and TEN Mike-Foxtrot HP are in the same thread.

There's a 7 to 10 HP rated commercial static unit laying about right here that I took OFF my Cazeneuve 7 HP HBX-360-BC as a seriously bad joke. Best news is that it had crippled the poor French girl so badly and for so long she has very little WEAR!

Ten HP Weg ODP idler motor, brand-new, Brazilian, not Chinese (and the Weg clan were German immigrants, even so, BTW) shipped and liftgated here was right around $400. You already HAVE what you need in the "static" parts project to start and run such a critter.

USED 3-Phase motors for idlers can be had from free, through $50-$200 ELSE keep looking.

Single phase it? Well.. you were only going to have a best-case 3.1 HP with a static converter anyway, so a 5 HP single-phase motor could actually be an improvement, and will also run cooler, and even smoother, than a bef**ked 3-P would have done on dropped-phase.

The best advice PM has doesn't cause utility-mains grade 3-P nor cash money to fall out of the sky, no.

It surely can help you waste less of what you DO have.

Yea thats what im kinda starting to learn and think. It looks like a static is acceptable at lower hp ranges and like i say i have used them before on mills,dust colletor motors and table saws with no bad issues at all. Im just going on past experience from utilizing it on much smaller stuff. It looks the larger you go in hp the loss becomes much more noticable as the math gets larger making this kind of converter useless. Guess i might have to start looki g for an acceptable candidate for arotary but just hate to swollow that pill!
 








 
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