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Old 03-15-2011, 09:12 PM   #16
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hELP! Amperage needed for 220V motors


My first guess from your description would be that your machine is powered by a three-phase motor and the other motor is a homebrew rotary phase converter. I believe the second motor is sometimes called an idler motor. However, in such a scenario both motors would usually be 3 phase, which your pics ALMOST rule out.

I've heard it said that all single phase motors are in fact three phase motors with the addition of a starter circuit that temporarily provides power to the third phase. The wiring for all three phases is brought out when an external starter is used: even if the starter is internal I believe it can generally be easily hacked on those motors where the starter is replaceable, which I think applies to all or most large motors, at least. Ultimately I don't know if the third winding is of the same gauge, but it probably is. That way the manufacturer only has to build one motor for 3 and 1 phase apps, and besides, a smaller gauge starter winding would probably be hazardous.

Soooo if the previous "owner" really knew his stuff he could tack a single phase motor in as a rotary phase converter.

He could even have bridged two single phase motors to create a 3 phase machine. I've never heard of that being done, but as I understand such things, you'd gain about 30% more power with such an arrangement. And probably a bit more efficiency. I've heard it said that when rotary phase converters are properly sized and tuned, no power draw is seen on the meter during idle. This is not to say that it does not draw power: just that the power factor is so whacked it doesn't register.

The power gain comes from the fact that a motor running on single phase is in fact a crippled 3 phase motor, with (in some cases) a built in STATIC phase converter called a run capacitor. It is well know that when a static phase converter is used to adapt a three phase motor to single phase power, about %30 of the nameplate HP is lost. Rotary phase converters don't suffer such losses, which is why they are still popular despite being about 5X as expensive as static converters.

It stands to reason that if you add a rotary phase converter to a "single phase" motor, you'll get %30 greater than nameplate HP.

All in all a pretty complicated way to get %30 more power, but esp. if the spare motor is on hand, adding the power electrically might have been easier than boosting power mechanically with a motor swap.

Oh dang I just noticed someone else hit the phase converter tip. Didn't see that on the first pass through the thread. And I didn't notice where you said the motors were pullyed together. Never heard of that one.

As to the amperage of the motor vs. wiring vs. breaker size, it can get pretty complex. With two motors to be switched on simultaneously perhaps more so. I'm not an expert but generally I can figure it out on a case by case basis, at least in the simple case of a single motor. Too bad motors don't have instructions on the nameplate like my Bosch 240V washer/dryer does. It says something to the effect of "use wiring suitable for 30A and fuse at no more than 20A". That having been said, I think it's generally OK to size the circuits for the nameplate rating: been a while so I can't remember if you use that or look it up in a NEC table.



-Jeff

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Old 03-15-2011, 09:45 PM   #17
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hELP! Amperage needed for 220V motors


I was wondering about phase converter too. the seller told me the other interesed party that came down siad that big thing onthe side is a magnetic switch. i have looked at othter on sale at machinery auctions and they say 3 pase with magnetic switch. sure that is factory..same color thoughthe others i have seen are brown. Theseller inherited this from a man that had a milling maching and from work one of those very intelligent macinery people. It hs a 50amp 120/240 on it but that is probably due to the fact that he wanted to use off same outlet at his 200 eqip like welder. So ther is NO way of getting hold of the builder..other than seance, lol.
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Old 03-15-2011, 11:42 PM   #18
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hELP! Amperage needed for 220V motors


Thanks for posting the photos and by the way BOTH motours are single Phase motours they are NOT three phase at all.

The quickest giveaway is the capaitor can cover on both motours and both motours they are about 2 HP a peice not like a true 5 HP motor they will be much larger and you will need much larger circuit to handle the true 5 HP's

The true 5 HP's single phase verison will draw about 28 amps @ 240 volts for each motour so therefore you will draw about 56 amps when you have both motours running.

mysterylectric.,

Quote:
I've heard it said that all single phase motors are in fact three phase motors with the addition of a starter circuit that temporarily provides power to the third phase. The wiring for all three phases is brought out when an external starter is used: even if the starter is internal I believe it can generally be easily hacked on those motors where the starter is replaceable, which I think applies to all or most large motors, at least. Ultimately I don't know if the third winding is of the same gauge, but it probably is. That way the manufacturer only has to build one motor for 3 and 1 phase apps, and besides, a smaller gauge starter winding would probably be hazardous.
That first part that is NOT true at all the single phase motours have complety diffrent winding set up than triphase windings the single phase windings are shifted at 90 compared to the triphase they are shifted at 120 and the triphase will have no starting winding at all due they are self starting when you have full triphase supply there and single phase motours will have starting windings very rare some single phase motours do not have starting winding but a shifted winding more like perament running winding.

Now for the starter I rather keep it larger if you can the starter size will depending on the size of motour{s} and phase and voltage and typically single phase starter will be larger than triphase is however you can able use the triphase starter on single phase motours as long the amparage is not excessed the starter rating.

So please rescearch it first before you make the statement that can save other peoples greif if they find out it was a error on it.

I am not being harsh but I just speak from fact and experance on them.

Now back to the OP .,

Due you have both motour draw about 15 amp each so the total circuit capaity about 30 amps so therefore you will need sized the circuit for 30 amp however the breaker size will depending on how well the motour can start unloaded { per NEC code we can go up much as 250% of FLA ( full load amps ) but I will stick about 175% or so so a good chance you may have to use the 50 or 60 amp breaker as long the starter is functing properly.

mysterylectric.,

I have heard few peoples bridged both single phase motour in triphase supply that useally in open delta format for addtional power the answer is no it still the same as single phase supply.

To OP.,

Can you take the starter cover off and snap a photo I will like to check it out little closer to make sure it is safe set up.

Merci.
Marc
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Old 03-16-2011, 07:09 AM   #19
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hELP! Amperage needed for 220V motors


Thank you for clearing up that misconception of mine re: windings of 3 phase motors. I shouldn't be passing on rumors even if I loosely disclaim them as such.

-Jeff
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Old 03-16-2011, 11:12 PM   #20
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hELP! Amperage needed for 220V motors


I got pics. And yes my brother whos a lineman said that the amps woud be the total draw so i will need to hook up 30amp, dagnabbit.
I am just wondering if 30amp would be too much for my 15 amp cmpressor and 21 amp planer (both 220v) I mght just have to make a conversion cord and save myself a whole new set of wiring.theyare wired for 20 amp receptacle. So pic proves same motor..i just had to hold camere under machine..to think i was going to get a mirror and take a pic lol.

when i blew up switch pic the big area says 52 or 62 amp 600vac and to the right it lists volts then hp i can read the 120 = 3hp it looks like 208 and 230 is 7.5 hp. I was wiggling toomuch trying to hold that on my bad knee. I just left for surgery pre-op..so sorry,hope this helps. I am 300km away so thats as good as it gets
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hELP! Amperage needed for 220V motors-china-006.jpg   hELP! Amperage needed for 220V motors-china-008.jpg  

Last edited by 1488rob; 03-16-2011 at 11:20 PM.
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Old 03-17-2011, 07:06 PM   #21
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hELP! Amperage needed for 220V motors


Frenchie I got your pics dont abandon me lol. realy though I repsect your expertiise dying to see what you think of switch job
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Old 03-17-2011, 09:58 PM   #22
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hELP! Amperage needed for 220V motors


The photo is pretty burly but one thing for sure that is not a standard starter size in there.

When you get all rest up when you feel better then can you retake the photo but more clearer ?

And the other condersation is the wiring connection layout it kinda bother me a bit I don't think this is a correct wiring layout what I can see.

Do this starter have a simple on and off or start and stop pushbutton or a simple toggle switch ? that will affect the way it connection but for now just tell me real quick if which one it have.

As far for both motor there is a common junciton box for both or both cables run to the starter box ?

Hope you make it thru ok with surgey or other needs.

I will be on standby until you recover it first.

Merci.
Marc
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Old 03-18-2011, 03:28 PM   #23
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hELP! Amperage needed for 220V motors


merci for your concern, no surgery yet..unfortunatley they cant get me in until i have job at nuclear plant outage
It is a industral type start button/ big RED stop button.
It is outside covered by tarp..too big to move in my soon to be house now workshop. It is over 300kg so it is outisde where i can move it again with my tractor frontloader. This is why the condensation.
So is this what they call a magnetic switch? It looks original unless the previus owner painted it..a very good job. The others I have seen were tan/brown. that pic is better than the one that i did with my cam after the SD card wouldt load i computer. If I had know it was blurry I would have retook,but I was allready in Portland before the card worked. i hate my laptop sometimes
Thanks,
Rob

Last edited by 1488rob; 03-18-2011 at 03:32 PM. Reason: missed something
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Old 09-18-2013, 10:04 PM   #24
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hELP! Amperage needed for 220V motors


2 yrs ago I needed help wiring power on this 3phase equip converted to single phase 12" planer.

I have 30amp 220v wired and havent had problems. I ran it for about 10 straight minutes or so and i heard hum odd so shut it dowm. I started it up 20 minutes later after cleaning out wood chips that were on pulleys in case heat problem. I ran again for about 20 minutes and heard hum then a minute later it shut down. I hit stop. I then hit start and heard a ' CLUNK!" i hit stop. I then opened the power box and cabinet. cleaned it out again. i took the cover off actual power block as is in pic and hit start again "CLUNK" and it was from behind the powerblock. I dont know electric so i might not be terming it right. i did get a zapwhen touching it. i diconnected the power then and checked coneections looking for any melted wire or disconnect. Even after waiting 15 minuted i get that "CLUNK sound like a starter solenoid when it cant turn starter. I am sure that its some safety switch and thats why it was put in to connect both motors. there is no fuse on the block its just has connections and is 3" by 4" . I am wanting to know if its doing that because one of the motors burnt out or if i need to replace block. Thanks for help
EDIT:
This is the photo i was able to copy it off old thread. this is the powerbox that comes from main power and start/stop switch..this is the CLUNKer


just ressurecting for the pics on the post i just put up

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Old 09-19-2013, 02:58 AM   #25
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hELP! Amperage needed for 220V motors


Take the belt off the motor and see if it's free.
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Old 09-19-2013, 09:51 AM   #26
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hELP! Amperage needed for 220V motors


If that is a contactor/starter in the picture, you will hear a sound when you start it and stop it.
A safety switch will drop out this starter too.

Maybe nothing is wrong and you have a safety switch problem stopping the motor when you are using it.

Your blade assembly is another place to look. A bad bearing can cause all kinds of noises and unexpected shutdowns.
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Old 09-19-2013, 08:16 PM   #27
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hELP! Amperage needed for 220V motors


wierd..the title changed..must have been when i pulled the photo form the old thread.

The belts are fine i felt them.
The noise is actually more of a spring being released " CLINGGG!" so the "contactor might be bad? I wonder if this is the right contactor for motors. I just checked it again today and sulrely no melt wires.
when is turned off it was not violent not smoky or otherwise..it just shut off, there was an off hummm minutes before. as I said, this was the second time i ran it for over 15 minutes and this time i didnt turn it off in time. With the wood chips it could be over heating but i cleared all debris.

What is the purpose of this box?

EDIT: i checked under black plate. this is a starter block. when you hit start the connecting bar connects 3 poles simultaneously This also applies when youhit the stop button, it clicks back up. So I am not getting power to motors...but all looked connected. It appead a MOD decided to destroy my old thread giving it this name because i resurrected it ;then got a pic, but NOW that pic is ONLY pic i have of other box and NOW icant get it because the other thread was destroyed/ARRRGH!!

power goes from outlet to the contatctor, then to the start button then a junctionbox that splits the power to both motors. thats what confused me...I would think the box WOULD SPLIT the power not send power to be split..whats the purpose then?
I am very illeterate on electricty. Very intelligent but not studied enough in electric..im a mechanical person

Last edited by 1488rob; 09-20-2013 at 12:22 AM. Reason: WHERES MY OLD THREAD MOD!!!
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Old 09-20-2013, 07:56 AM   #28
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hELP! Amperage needed for 220V motors


Contactor could be bad and not passing power through. It could also be this is more than a contactor. It could be a motor starter with over current protection built in.
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Old 09-20-2013, 10:24 AM   #29
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hELP! Amperage needed for 220V motors


Two motors?

Maybe you should get help again? This is very simple to troubleshoot if you know what you are doing.
It sounds like you do not know. I would get some help if this is an important machine.
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Old 09-20-2013, 02:55 PM   #30
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hELP! Amperage needed for 220V motors


Yes JV I did allready write that I am electrically illiterate BUT I am intelligent and learn easy. I did write dwon the flow pattern also. For some reason the old thread of the same name has a pic of one of the TWO motors which was not erased. I have no idea how the title got changed on this thread. I wired in a 220v/30a breaker which should be efficient. Back 3 yrs ago my lineman brother helped me on figuring breaker.

So what would be the simple troubleshoot? its a real odd tight space under machine. Its 650lbs so not something i can turn on side. I was considering setting to V on meter and checking for power at junction box (no pic) where power splits AFTER contactor, but a little nervous as its tight and when checking a live circuit i would want to slip because nowhere to go and would be glued to box if i grounded, Heres a pic of motor spec.. sorry if i cant get image flopped


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