Phase converter questions

admin

Just purchased at auction a 2 ton 3 phase chain hoist for my shop. Does anyone on here have any experience running a hoist with one of these? I am leaning towards a phasemaster made by Kay Industries because their 5 HP converter weighs twice as much as a phase a matic of the same HP which says something about the generator. Just looking for a little input here. Thank you.Dutchman
Reply:If that is the only piece of equipment you are going to need the phase converter for, you may want to look at the motor in the hoist first.  Check the NEMA frame number and see if you can find a reasonable single phase motor in the same frame size.  Many times you will find its much cheaper to change out the motor than buy a phase converter.
Reply:Someone with more experience on the static converters will have to answer if they will work on a hoist.  My feeling is they probably will not.  With no weight on the hook, yes it would start the motor, but if you are near capacity with weight already on the hook the motor is going to be under a heavy starting load.  Also, with static converters the motor is really only running at 2/3 of power rating.
Reply:Like you said, with a static converter, you can never max out the motor because the converter won't allow it. So it depends on what you want to do with it, but I agree with just changing the motor out. It is less things to go wrong, plus you know the motor will last.
Reply:Originally Posted by 7A749I have a static converter on my lathe & have yet to stall it out.It has a 12" chuck on it & I've taken some pretty heavy cuts with it, no sweat.Can't say for certain, but its a lot cheaper than a VFD or rotary unit.IMHO of course
Reply:A static converter won't start a motor with much of a load on it.  On a hoist, it's going to have a load on it immediately.  On something like a lathe, or saw, it doesn't.  A rotary phase converter is really just a static phase converter turning an idler motor.  The 3 phase is then taken off the idler motor in parallel.  Essentially all a static converter does, is converts a 3phase motor into a capacitor start single phase motorIf you can pick up a static converter like listed above, and find yourself a surplus or scrapped motor, perhaps something with a damaged shaft you can just cut off flush, you've got a perfectly good rotary converter.Last edited by anickode; 02-06-2013 at 10:13 PM.You didn't build that.'85 Miller AEAD-200LE
Reply:I have a static converter on my south bend 17" turnado and it runs fine, but take that same converter and try to take a 1/4" cut from using the start button and it will blow the breaker and probably hurt the converter.I'm assuming that he will want full use of the hoist and having a 33% handicap will effect the usage of the hoist on a static.
Reply:I have been reading on phase converters and transformers and trying to figure out a few things that are not answered so that I can understand it. I get the idea of using a 240v 3 phase motor, using a 240v single phase power to drive two leads of the motor and generating the 3rd leg and ending up with 3 leads creating 3 phase power at a REDUCED HP rating. This is because you are not driving the 3rd leg, but rather USING the 3rd leg for to derive your 3 phase power.  Here is my question....why not use a HP to HP setup?Why not use a 5HP single phase motor and use a shaft coupler to drive a 3 phase motor and use the 3 phase power coming out of the 3 phase motor to use on your equipment? It would be true 3 phase, it would be true 5 HP.And if you need 240v 3 phase, you would be done!Let's say you need 460v 3 phase? Use the same setup but substitute a 3 phase motor that is 460v? This question should be in a different section, I know, but this thread already exists and is related. Sorry for  the hi-jackLincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain
Reply:i say VFD From china the price is even better but there still decently priced from the US Here is one $112US and free shipping with fedex
Reply:Kay is one of the best , make your own , fuzed disconect , small pony motor and big 3 phase motor see practical machinest for advice , they have a whole thread on them . Ox over there has a 60hp Kay on a 200 amp panel runs his whole shop of screw machines on it .
Reply:Thanks everyone for the response. I wont get to everyone here but will just make a few comments. Static converter will not work on a hoist because of the load at startup. I never thought about switching motors but then this will not be the only piece of equipment that it runs. Looking to add a press and maybe a shear.Pavinsteelman: That is why I was leaning that way ( Kay ) . They seemed to be the most knowledgeable  and have the best product.Thought about making my own but very busy with work now and no time for it. Unless something changes my mind I think Kay will be my choice. Thanks again.Dutchman
Reply:Originally Posted by Joker11I have been reading on phase converters and transformers and trying to figure out a few things that are not answered so that I can understand it. I get the idea of using a 240v 3 phase motor, using a 240v single phase power to drive two leads of the motor and generating the 3rd leg and ending up with 3 leads creating 3 phase power at a REDUCED HP rating. This is because you are not driving the 3rd leg, but rather USING the 3rd leg for to derive your 3 phase power.  Here is my question....why not use a HP to HP setup?Why not use a 5HP single phase motor and use a shaft coupler to drive a 3 phase motor and use the 3 phase power coming out of the 3 phase motor to use on your equipment? It would be true 3 phase, it would be true 5 HP.And if you need 240v 3 phase, you would be done!Let's say you need 460v 3 phase? Use the same setup but substitute a 3 phase motor that is 460v? This question should be in a different section, I know, but this thread already exists and is related. Sorry for  the hi-jack
Reply:No, actually he's right.A rotary phase converter is a 3 phase motor, running on the 2 legs of single phase.  The third leg of the motor actually inductively generates the third leg of power.It will drive a 3 phase motor of equal or lesser rating at full power, and it will operate 3-phase transformer based machines, such as welders, at full capacity.You cannot feed 240 into a motor and get 480 out, but you MOST CERTAINLY can feed 2 legs of single phase into one, and get 3 phase out.You didn't build that.'85 Miller AEAD-200LE
Reply:Originally Posted by anickodeNo, actually he's right.A rotary phase converter is a 3 phase motor, running on the 2 legs of single phase.  The third leg of the motor actually inductively generates the third leg of power.It will drive a 3 phase motor of equal or lesser rating at full power, and it will operate 3-phase transformer based machines, such as welders, at full capacity.You cannot feed 240 into a motor and get 480 out, but you MOST CERTAINLY can feed 2 legs of single phase into one, and get 3 phase out.
Reply:Here's a 3 phase rotary I built myself to run a 2HP mill. They're actually quite simple to construct in terms of passing the power to the driven motor (hoist in the case of this thread). I added complexity for a "start" and "stop" circuit (extra relays and contactors). This build used a surplus 5HP 3 phase motor, parts from Mcmaster and scrap metal from the "pile".The idea of using a single phase to run a 3 phase (coupler between shafts) is another way to generate 3 phase power and in fact will be "cleaner" power (proper phase angle seperation). However, you won't get a 1 to 1 match up in terms of HP, ie: 5hp single running a 5hp 3 phase becasue there is power loss of running the 3 phase motor stand alone (without load). Also, it's not good practice to run a load motor off the idler motor (generator) without the use of run capacitors to absord the load surges.There are many threads across the internet for building 3 phase rotary converters and some get very deep and technical. The only time the "cleanliness" of the 3 phase power is a concern is when electronics are involved (CNC and other simliar equipment). Running motors is as basic as it gets. Attached Images
Reply:My main machine shop I use is located in the boonies, just like my shop. They have well over $500,000 of machinery running from a single phase 220 feed. He does this by powering from 3 phase motors and having a phase aligner and blah, blah, blah.... I'm just saying to swap motors because you would need to feed your rotary 24/7 (only when your working in your shop) or always have to start and stop it just to be able to use the hoist and not suck more juice then needed. For simplicity, i'd just change the motor and use a static for your lathe.
Reply:Nice RPC markfuga!My thought would be you'd need to use an RPC also. One advantage of a RPC is that the power generally gets cleaner the more machines you hang off it. With a hoist I doubt noise would be an issue. As mentioned a static converter has greatly diminished start up capacity. For example, the tire shop across the street runs a big old air compressor off one. They can start with the tank near empty... but not full. A VFD may or may not work it will depend on the hoist. The VFD solves the start up issues for the motor but the hoist has a bunch of stuff other than the motor... brake, sensors and such, most small VFD's are designed to run motor loads only. (Same goes for a static converter.) You really need to check with the manufacturer of the hoist. If the hoist is mechanical then a VFD should work.That's said, it's very common to run hoists off VFDs to achieve easy startup and save energy but nearly all these systems are being fed three phase to the VFD and the hoists are unboubtly "designed for vfd" operation. It's possible that the VFD is just running the motor and the controls are separate.Interestingly, our power co is running rebates on VFDs for air compressors because they can save a lot of energy if they cycle a lot.
Reply:Originally Posted by OldSkullKiller you got it wrong.We talking about MOTOR not GENERATOR here! You never found any power coming out of your 3 phases motor with a set up like this, and their is no way you can get 460V 3 phases from 230V single phase, you need a step up transformer for this and a 208/230V 3 phases power source....If getting about 66% of efficiency is your goal go ahead..
Reply:Stable 440V out of this?? I never seen that happen in 33 years working with electro mechanics (I use to be one too working on Allis Chambler electric hoist...) But maybe with some magic gizmo and Kryptonite magnet who knows! Joke a side, don't get me wrong, motor-generator exist they are stable and reliable since their conception are specific for that task but we talking off another animal here. If ever someone manage to success I'm curious to compare the efficiency of his design to a step up transformer setup...Markfuga Amazing work! Your explaination are right on the target too! Last edited by OldSkull; 02-08-2013 at 02:40 PM.Miller MM211Esab Mini Arc 161LTSEsab Handy Plasma 380Duck tapeTy- rapKool-aid
Reply:if i change my SINGLE PHASE 10hp 40amp compressor motor to a 3 phase motor running off a phase converter motor system.......Will this lower my over-all amperage being used off my service connect? (Because im pretty much tapped out) Or will i be useing up more of my service connect amperage to run these two devices? Would i also be able to have the phase converter start off the pressure switch at the same time as the compressor?  I dont have a grand$ for a new 10hp motor and 3phase motors are cheaper. Im thinking of just changing to a 7.5hp and lower the rpm   any answers appreciated, thanks        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:Cheaper and efficient solution is getting a chinese made single phase motor or this Leesonhttp://www.ebay.com/itm/Leeson-10HP-...item3a7b1ff339I order all my Baldor motor from Williamson, you can get a10hp single phase L1512T for $150 to $250 less then any place in the US..http://williamsonneelectric.com/bald...torl1512t.aspxLast solution is what you already figure out, install a 7,5Hp motor, you loose some cfm, lower your Amp needs but get no gain on your electric bill since the motor have to work harder to feed the demand.Miller MM211Esab Mini Arc 161LTSEsab Handy Plasma 380Duck tapeTy- rapKool-aid
Reply:I'm no electrical expert, but we run nearly all of our motors on 3ph. We like not having to deal with start capacitors and *the option to run the motor in either direction.* I would think this is why the chain hoist has a 3ph motor. I use both sides of the knives in our bale chopper and have a bi-directional conveyor with a simple switch. 1ph motors won't workload this, or at least with my understanding of it. Switch two wires and you change from raise to lower. I don't think a 1ph motor will work in this situation. But I haven't seen your hoist and may be wrong.Lincoln Precision Tig 185Lincoln Power Mig 256Hypertherm PM 45Everlast 140STSmith O/A
Reply:Originally Posted by manningI'm no electrical expert, but we run nearly all of our motors on 3ph. We like not having to deal with start capacitors and *the option to run the motor in either direction.* I would think this is why the chain hoist has a 3ph motor. I use both sides of the knives in our bale chopper and have a bi-directional conveyor with a simple switch. 1ph motors won't workload this, or at least with my understanding of it. Switch two wires and you change from raise to lower. I don't think a 1ph motor will work in this situation. But I haven't seen your hoist and may be wrong.
Reply:thanks OldSkull !!  i'd luv to hear  you  about mannings post more man.  on my post ...Let me understand this.  If i run a 3phase 10hp motor....these use about 15 amps....and if i use the 10hp 3phase motor phase converter..that's another 15amps = 30amps......but ...if i stay with my single phase 10hp motor....it equals = 40 amps draw from my service panel.....or is the phase converter drawing mor than 15amps....or would i need bigger than 10hp  converter for 10hp motor.....thx man, jus trying to soak iin a little        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:The worse load for a RPC "IS" a compressor! You need a 2 for 1 ratio, this mean a 15kw idler to power a 7,5 kw 3phases motor (20hp for 10hp), that's why I don't suggest you this solution, Here the reason....A 7.kw/10hp RPC need  breaker of  25 to 35 amp  to run safely depending of the load, a 15Kw/20hp RPC need twice that.(50 to 70 amp) The estimation you give in your post are based on what you read on the motor plate, but those number are for a 3 phases power source a "Constant power transfer source" that is a lot more efficient than a single phase source..Even if you find a used 20hp idler motor and a way to power it, their is a reason he have been replaced and it's not because their is a expiration date on it like a box of cake...They come from industrial sector and are pretty beat up otherwise they get rebuilt.....I'm sorry but like they always said their is no free cake...Miller MM211Esab Mini Arc 161LTSEsab Handy Plasma 380Duck tapeTy- rapKool-aidk man. Thanks for  your answer. I will tread on. thanks again        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:I have not posted for a while but i have had experience in this also.  I have a 2 ton yale 240volt 3ph chain hoist also that i tried to run on a static also.  It wouldn't do it at all.  Then i tried to run it on my 5hp homemade rotary that i ran my bridgeport with.  The rotary wouldn't do it either.  As far as i could tell the immediate load on the hoist motor with the made up leg wasn't enough.  Also i'm not sure what kind of brake yours has but i had to make sure the brake was on the two good legs or the fields wouldn't come up fast enough to pull the brake loose and then it was a complete stall for the hoist.  After all this i had 3 phase installed in the shop.  On a side note, I also have a Speedaire 4 piston 2 stage compressor that had a 10 hp 3 phase motor on it.  The local motor shop that i have been dealing with said i could replace the 10 hp 3phase with a 7.5 hp single phase because it has more starting and running torque with the capacitors in the circuits. I did not change pulleys either.  This does make some sense to me and it has been running happy for the last 3 years.  The only reason i did this was that its on a pallet and i can fork it on a truck and plug it into someones dryer outlet if need be.
Reply:I  would look into a phase convertor VFD.  There are many sources, here is one.  You may be able to find one much cheaper.  A friend runs his Bridgeport off of one (with variable speed option), also his 16" lathe on another.  I personally built my own rotary phase convertor and have been using it in my shop for many machines and air compressor for about 20 years.  Mine is using a 10 hp 3 phase motor, I build one for my neighbor out of a 20HP Delta wound motor. His starts a 10 hp aircompressor  with ease.  Mine will start a 7.5 compressor even when cold.http://www.driveswarehouse.com/s-267...ect5=&select6=
Reply:Originally Posted by marvin jensenI  would look into a phase convertor VFD.  There are many sources, here is one.  You may be able to find one much cheaper.  A friend runs his Bridgeport off of one (with variable speed option), also his 16" lathe on another.  I personally built my own rotary phase convertor and have been using it in my shop for many machines and air compressor for about 20 years.  Mine is using a 10 hp 3 phase motor, I build one for my neighbor out of a 20HP Delta wound motor. His starts a 10 hp aircompressor  with ease.  Mine will start a 7.5 compressor even when cold.http://www.driveswarehouse.com/s-267...ect5=&select6=