Building a Phase Converter - Part 2
Vložit
- čas přidán 19. 07. 2024
- This is part two of a three video series on building a phase converter. In this segment we will as some safety features, like a circuit breaker and motor starter.
Part 3 will be about mounting it all in an enclosure and wiring it up in the shop.
Magnetic Motor Starter : amzn.to/2fPSVk5
Start/Stop button: amzn.to/2ytgpqs
Push Button: amzn.to/2xqSOBS
E-Stop: amzn.to/2fPOs0C
Breaker (20amp): amzn.to/2xlT3mD
Panel Indicator Light: amzn.to/2y4wvp8
Document I followed: www.practicalmachinist.com/Fit...
Midwest Surplus Electronics: www.midwestsurplus.net/
Song: Strange Things [Rewind Remix Release]
Music provided by Rewind Remix goo.gl/08ZthI
Artist: MOS3S - Věda a technologie
I don't know how it got wired in your final project, but in showing your testing, you had the estop switch after your pushbutton for the motor starter coil. You'd actually want to put the estop in the string first, so if the pushbutton were to fail closed, you'd de-energize the coil and stop the machine. it'd go Line -> Estop -> Start button -> Starter -> Start Button (load side of the contact). Otherwise, if your contacts fused, you'd have two sources of voltage, and you couldn't stop it with just the estop, you'd have to run and throw the breaker.
Hmmm...I will take a look at that and see about changing my implementation. Thanks for taking the time to leave a comment.
if you are still around could you assist me please
This series of videos is fantastic. It’s demystifying something that’s always been confusing to me.
First off, this is a very clear and simple explanation for a device that can get perplexing. Well done!
Now for a few quibbles from an old controls guy. Your stop PB should interrupt the power going to the start PB so that tying down the start PB with a screwdriver or a ty-wrap won't allow it to bypass the stop PB and turn on.
And since you already had created 120 volts going to the coil of your contactor, that would be the logical place for the lamp as well. It's bad enough to scab onto the ground for a neutral without doing it in multiple locations.
I know this is 6 years old but I have to say you are a very good instructor, I'm a retired HVAC Controls Design Engineer for commercial building.
Well thank you sir. I appreciate it. This series of videos has been helpful to a lot of people based on the comment I have gotten such as yours. I appreciate it. ~P
Very instructional series
been thinking about a converter build since i moved and lost access to 3 phase. thanks for clear and concise videos and explanation especially around the capacitors
What a good educator. Thanks.
Another great tutorial. Thank you.
Awesome stuff!!! With no overload section, that "motor starter" is just a 3 pole contactor.
Solinoid - contractor - motor starter
Solinoid has a magnetic coil when energized performs a mechanical task ( door latch, valves, bell, ...etc)
Contractor (relay) has a magnetic coil when energized performs a mechanical task of closing electrical contacts( switch or switches)
Lights, control circuits, motors( if HP rated) ...etc.
Motor starter has a magnetic coil when energized performs a mechanical task to close electrical contacts and also has an intrigal motor protective device incorporated with it. Some are resettable if tripped and have interlocking contacts of their own to interrupt the starting circuit
Great Video... very instructional
Makes me wonder why more people don't do this themselves rather than buy it off the shelf. Then again, at the sizing I'm going to need I'll likely purchase one. Nice job and I've enjoyed watching the build.
Hope you are well!
Tom Z
I agree that there is some point at which I would probably go the purchase route also. I think the third video will be the most fun for me because I played with more tools ;).
I am well. I hope the latest storm went easy on you. ~P
Looking forward to the next episode. I'm sure it's things like active balancing / monitoring for more stable output and dependability. Lots going on here but the storms are the least of it. :)
It's a motor rated relay. A motor starter contains some sort of additional motor protective device
It's not considered a "Motor starter" unless the contactor has a thermal overload with it (all one unit). Otherwise, it's just a contactor meant to make or break high current or frequent start/ stop loads (motors).
Yep, I caught that too. Also he used ground wire for the neutral connection, which is a no no if this doesn't come out of the meter main panel. Otherwise great video series, and I learned a lot.
Yup. And for all of the noobies out there, a 2 pole contactor is not legal. Hasn't been for ages. Use a 3 pole contactor.
I have to say you are living on a farm layout that most would give there right arm. A very nice place I really envy you Sir. Good day too. VF
Thanks for your great video. I have watches all three of them multiple times and probably will watch them more when im building mine. Just ordered all the parts. Btw did you ever found a better way to take the start cp out? I saw some comments about timer and some about the wiring being incorrect for the potential relay that was used, not sure which route to go for that piece. Any advice is appreciated!!
Thanks very much I did same and I can now run the motor
I plan on copy your job I think it’s a good plan a very smart and well thought
Nice job learnt alot what's the value of the start and run capacitors
The part where you added an indicator light to show whether power is on, might it be a better idea to run indicator lights for each phase leg, or would that just be redundant?
The difference between a starter and a contactor is a starter has a thermal over load added .to the load side of the contactor.
Great videos. What size wore are you using. Thanks
Awesome. The 120v lamp, didn’t you wire that across 240v though? I thought each pair of legs had a potential of 240v (ish)? Did I miss something? Brill video subbed thank you
On an American "Edison circuit", it's single phase with 240 volts available across the two hot wires. It's also 120 volts from the neutral (or ground in his case) to either hot wire.
Is there a real advantage on using e-stop VS a normal start/stop switch?am I missing a scenario where e-stop would be safer?
Was curious if it was back feeding to the starter capacitor and killed the relay. Maybe a resistor on the capacitor to bleed off the excess
Very nice video you did a nice job! we have them for 260.00 free shipping motor included
Danny F do you guys have a website or a way to be reached? Thanks
@@Redmech80 Did you ever hear back from this guy ?
dronai no sir I never did.
czcams.com/channels/8EW2NQZhDGjk_4ixUsUl9A.html
Kinda wish you had ran your start button circuit through the E-stop as well. You should not be able to press the start button and pull the contractor in with the E-stop pushed. Great videos though.
Hi, I am not able to download the document from the website in the link in the description. Where will be able to find it online?
Just wondering, if the hp requirement for the pony motor , is one step higher on the load motor.. example...5hp pony motor, load motor 3 or 4hp, then it means the power consumption will more than double . It means the power supply wires need to be upsize, circuit breaker need to be upsize.???
No, the total load will be a bit higher than the load motor, but not anywhere near a factor of two. Just a few percent due to friction loses and electrical resistance. In order to understand this, you need to understand how an electrical motor work. Here's a 20 thousand foot view that should help you.
When a motor runs, it also acts like an electrical generator with it's output 180 degrees out of phase with the input supplying voltage to the motor. Ideally, this generated voltage will exactly match the input voltage and counteract it, resulting in an effective voltage of 0 to the motor and cause the motor to draw no current. Obviously, this isn't the case since the windings in the motor have a non-zero resistance and generated voltage isn't generated with 100% efficiency. But the usual case is that a motor running with no load will be consuming very little current due to the opposing generated voltage.
Now when you apply a load to the motor, it will cause the shaft to lag behind the input slightly and cause the generated voltage to also lag in phase slightly being the input voltage. This causes less input voltage to be canceled, which in turn means that the motor sees a higher effective voltage, causing it to draw more current. This is why the current being drawn by an electrical motor increases when the load it has to spin increases.
For a rotary phase converter, you're taking advantage of this generated voltage on the unpowered phase of the pony motor. The purpose of the capacitors in the converter is to change the phase of the output so that the three legs are 120 degrees out of phase with each other (the 2 phase power being supplied has the 2 phases 180 degrees out of phase with each other. The capacitors are used to change the phase of one of them to either 120, or 240 degrees out of phase instead of the 180 degrees it's supplied to the system with).
The reason you want the pony motor to be larger than the load motor is simply because you want the pony motor to be able to handle the current requirement of the load motor and also to provide inertial mass to keep it spinning during transient load spikes (startup of the load motor, etc.)
Use a contactor with auxiliary contacts as a seal in circuit.
kleco pliers for sheet metal?
Can I run my 3 phase 5.5kw 2800rpm cnc spindle safely with this setup ???
Does the pony motor need to be 3 phase or how do I get the third leg coming out
These are great vids BUT i purchased my panel and 10 hp motor HOW do I know my panel is wired like you are demonstrating, But it is great knowledge
If you purchased a panel retail, then I hope they did all this work for you.
Is the pony motor just a regular 3 phase motor?
Yes. Came off a bandsaw
What is the motor? or is the motor a generator head?
can you assist please ANYONE, my start cap of 260mfd started the motor then began cooking, is birdranch telling us to switch the cap off once the motor is running?
A start cap is only in the motor circuit to help get the motor spinning. It MUST be removed from the circuit immediately afterwards. This is also conveyed in the schematic that I reference.
You need bleed off resistors for the caps for safety!!!
What size is your pony motor?
This is great and thank you for this video. But at this point in your build, a VFD is cheaper.
For a single machine perhaps. Rpc can operate several machines when sized accordingly. I have large cnc machines that have inverter drives already and I could run one machine on single phase or 4 machines with an rpc. Depends on your needs. Lots of variables involved and not necessarily a true statement.
@@glennedward2201 I could perfectly match 3-4 machines to VFD's for the cost of a single 7.5hp- 3phase motor.
@@ballzack57 For a Weder?
@@ballzack57 Keep in mind a VFD will split power from two legs across three legs, so there is roughly 33% power loss. An RPC generates power on the third leg, so the machine will have full power. My vertical mill on a VFD noticeably lacks power with larger face cutters. Also, some complicated machines (my Burgmaster turret drill for example) do not play nice with VFDs, so the RPC is the only option.
In some cases a VFD is a fine option if cost is the only thing that matters to you. But not necessarily the best option for performance. Sometimes needs of specific machines and overall performance are more important than cost.
Ajarin saya cara membuatnya pak
used magnetic contactor and timer for running capacitor cut off. overkill? :)
run cap cut off or start cap cut off?
sbirdranch sorry i mean start capacitor. Your video helped me alot to understand how it works.
@@itsmelvyn I figured that was what you meant. So is it overkill? No. You have to get the start caps out of the circuit somehow. Glad the videos where helpful. I wish I had more subjects like this one. ~P
Sir its okay for a 220 V power supply ?by the way im from Philippines😊
Starter implies contactor and overload together. A contactor isn't a starter. Also breakers don't protect for overloads effectively that is why they are called short circuit protectors not overloads.
Thanks for your video and please help me! I got a 10 hp 3 phases motor to build my rotary converter but I’m having a hard time to balance the voltage T1 / T2 / T3. If I use just the run capacitor (830 mf), I can’t start the motor. But as soon I add 70 mf the motor start without the run capacitor by itself. Here are my tuning poor results.
CP CS Vab Vac Vbc
126 0 227 365 505
147 0 226 310 483
168 0 226 225 433
178 0 226 205 417
178 14 230 183 397
0 42 231 78 305
178 63 231 28 256
126 63 231 42 272
wrong connection potential relay
Your relay wasnt wired correctly that's why it failed on you. YOU have your L1 going to 5 on relay that's correct and 1 on relay going to start cap that's correct now YOU have the other side of start cap going to ghost which is wrong you run that one to L2.
Now YOU have the 2 on relay going to the same post on your run capacitor as your L2 which is wrong the 2 on relay needs to go to the post on run capacitor that's connected to the ghost leg.
There are way too many companies/people using potential relays for bird to dismiss this so easily. He clearly needed help, but didn't seek it, taking a clumsy way out. It's disappointing considering how well everything else was presented. He really should revisit this and correct it. I will research this myself to make sure you're correct too.
The Potential Start Relay can also be Positon sensitive with only one direction being up, if installed in a different position the contacts will stay closed which intern will cause the Start Cp to blow open. Just a friendly note. I really enjoyed the video and I am going to build one out of a 25 HP motor.
Thanks for the great presentation and very well done. :)
I have made this exact setup and so far haven’t connected it to a potential relay( i have it using a extra temporary switch) but I would like to get rid of that extra button. Anyone has verified that the wiring in the video was wrong and if done correctly potential relay would work reliably? Any help is appreciated!!!
@@moosaesfahanian8547 yes if wired correctly it will work reliably mine has been working perfect since I set it up with the way I described in the comment above
william hicks thanks for your quick response. I will go that route then. Would this work? ICM Controls UMSR-50 Universal Motor Starting Relay, 50 Amp, Patented Differential Voltage Sensing, Voltage Rating 110V - 270V AC, Single Phase (Maximum Voltage Contact Rating 502V AC) www.amazon.com/dp/B002JE3L9M/ref=cm_sw_r_cp_api_i_2GNEFb2K9YRK6
Dude! you aren't supposed to pull any current (> 500uA) on the ground leg!!!
A project like this one is not for the electrically uninitiated to undertake. You are working with high voltages and currents. A construction and/or wiring mistake can result in damage to the load, a
fire, or worse yet, a lethal shock.
I question the economics of building your own rotary converter. Unless you can get all the parts needed to build the unit dirt-cheap (those capacitors can quickly add up in cost-oil-filled capacitors are much more long-lived in this sort of application than non-polarized electrolytics, but are also more costly), a quality static phase converter with a UL/CSA/CE listing will likely be no more expensive,
especially once you account for the expense of a suitable enclosure. Also, static units make little noise, exhibit more accurate phase balance, and are more energy-efficient.
PleSe help me sir
I am working on a project i want to make a inverter thats input is 12 volts dc 200aims convert to 3 phase ac to run a moter of 5 hp plz sir help me
Nice educational video. One of the better ones out there.
However I see a fault in your wiring.
With the 'Stop' button locked off, and pressing the 'Start' button the unit fires up. This should not happen. The stop switch should be installed in the green wire that goes to earth ...... and that is where I see a second fault. If you plugged that unit into my power it would trip the RCD unit, (Earth Leakage) or whatever they are called in your part of the world. You can dismantle the contactor and change the coil out to a different voltage.
You are for sure correct on the stop button. Good observation. It is truly annoying when I hit the momentary start and it immediately turns back off. ~P
Does the hp decreases in the pony motor?
I like your clear and friendly presentation. Very informative only question I have is that you connect the contactor relay to earth or ground also the light is this not making the earth wire live .
To use the potential relay, for a true "self starting" converter, you must use the relay, with a contactor, running the capacitor thru the contactor and the relay to control the coil. I build all of mine that way. You turn the breaker, feeding the phase converter on and it starts on its own. In the event of a power outage, the starter will restart the convertor, but the connected equipment will not restart, due to their control circuits. It works well in my shop, it may or may not work for others.
I prepare using combination of time delay switch and relays. Timed the cut off of start capacitor.
Yes the ground wire goes to the same place as the neural line but they are never interchangeable.
I would think to run a neutral line just for the control circuit voltage, or bar that, copy a page or two from industrial electrical and throw in a small stepdown xformer for it - that, and this ground 120v hack is just a temporary hotfix until a proper control voltage supply can be given.
The clamp looks like a spring compressor, like the springs in the background. I like that safety pause, to evaluate wiring, before plugging in. What voltage capacitors are you running, and did you get them at MidWest?
@Mature Patriot. Sorry I missed this post. Yes my cap's came from MidWest. All of them except the 50mf, as they didn't have them. I had to order a group of them off ebay. I have extras if you would like to buy any. There is a safety factor figured in so my cap's are all 370/440v.
good job on explanation and basic instruction but a couple of coments on safety and general knowledge. First one of the comments made asks why more people don't do this and instead choose to purchase a ready made unit, The answer is simple a lack of knowledge and skill. as an industrial electrician and mechanic of many years a word of caution these are voltages that can cause severe injury of death and all though most of the the time a little pain and a minor burn is all that result each year there are many deaths caused by just these type of circuits. a general knowledge of electrical safety is a must. If you talk to just about any professional they can give you multiple examples of people they know who have been injured or killed because of a moments carelessness or ignorance. if you are unsure about anything STOP and get help saving a couple of dollars just aren't worth the results. Also one thing most don't take into account is arc flash which in many cases causes more damage than the shock. If you don't believe me just search youtube for examples. The temp. reached during an arcflash will reach temps higher than the surface of the sun. twice during my career I have suffered such burns from no fault of my own and I will always carry the scars that were the result. 3 PH is inherently more dangerous than single phase and should be treated accordingly. Enough for now I will put away my soap box and say be safe and have fun.
Still educating me. Great video. What size motor on the rotary do I need to run my 3HP lathe? I love the applause at the end!
You would want one size larger , so a 5hp idler would be what you want. ~P