# 3 phase to single phase



## AK_sparky (Aug 13, 2013)

The horsepower rating is a measure of how much power it puts out. Generally, a 7.5HP is a 7.5HP, regardless of how many phases. You shouldn't need to upsize it.

Someone wiser than me may know more about torque curves, etc, and might be able to say whether one is better than the other, but it's been done many, many times on compressors and I've never heard talk of any problems like that.

Can't help you with the white leads....


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## NC Plc (Mar 24, 2014)

As far as I know the main reason you go with 3 phase over single phase is efficiency, 3 phase is more efficient. For an air compressor I'd expect the single phase motor to consume more power and run hotter than its three phase equivalent.

I wish I could be more help but I don't work with capacitor start/run single phase motors.


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## hardworkingstiff (Jan 22, 2007)

I'm a little confused in that it seems you are working on a 3-phase motor in a shop where 3-phase is not available. 

What did I misunderstand?

Edit: OK, looks like the owner changed the motor and your just trying to confirm what he did is OK. I agree with the others that a 7.5HP motor does the same work whether it's 3-phase or single-phase.


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## psgama (Oct 26, 2015)

Yes. A 3 phase motor can be replaced with the equivelant single phase motor as long as Hp ratings are the same. HP is rated at the shaft. Your efficiency and PF will be way worse with a single phase motor though.


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## NC Plc (Mar 24, 2014)

hardworkingstiff said:


> I'm a little confused in that it seems you are working on a 3-phase motor in a shop where 3-phase is not available.
> 
> What did I misunderstand?


It was a three phase motor and they replaced it with some sort of capacitor run/start single phase motor. Now it's tripping a 50 amp breaker, which is odd to me, and killing capacitors.

I derped and looked at 3 phase motors haha.


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## hardworkingstiff (Jan 22, 2007)

You might want to look into the ambient temperature. 

What do the amps look like as the pressure is building in relation to the nameplate rating?


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## psgama (Oct 26, 2015)

A 7.5 HP 240v motor is rated for an FLA of 40A. The breaker protecting it should be 100A by CEC


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## NC Plc (Mar 24, 2014)

psgama said:


> A 7.5 HP 240v motor is rated for an FLA of 40A. The breaker protecting it should be 100A by CEC


I looked at the wrong table.


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## joebanana (Dec 21, 2010)

I think I know what the problem with the capacitors is, "made in China". Probably full of PCB's too.


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## hardworkingstiff (Jan 22, 2007)

NC Plc said:


> Isn't a 7.5 HP motor at that voltage gonna pull 22 amps? Why would it trip the breaker while running?


Table 430.248 says a single-phase 7.5HP motor at 230V should have a 40A current rating. 

I wonder what the voltage is when the motor is running?

What's the amperage?

Is it possible the motor is not cutting out the start capacitor when it should? What effect will that have on the motor?


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## NC Plc (Mar 24, 2014)

hardworkingstiff said:


> You might want to look into the ambient temperature.
> 
> What do the amps look like as the pressure is building in relation to the nameplate rating?


Ambient temp caused one of my air compressors to keep tripping its own thermal breakers, had to install a thermostat / exhaust fan / etc just for it.


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## NC Plc (Mar 24, 2014)

hardworkingstiff said:


> Table 430.248 says a single-phase 7.5HP motor at 230V should have a 40A current rating.


Yea I'm a tard, I went to engineering toolbox instead of pulling out my NEC and looked at a 3 phase table without thinking. :whistling2:


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## hardworkingstiff (Jan 22, 2007)

NC Plc said:


> Ambient temp caused one of my air compressors to keep tripping its own thermal breakers, had to install a thermostat / exhaust fan / etc just for it.


Also, how often is this compressor cycling on/off? Is the compressor large enough for the shop usage of compressed air?

One other thing you might try, lower the cutout pressure if the shop can deal with it, that might reduce some of the strain on the motor.


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## hardworkingstiff (Jan 22, 2007)

NC Plc said:


> Yea I'm a tard, I went to engineering toolbox instead of pulling out my NEC and looked at a 3 phase table without thinking. :whistling2:


Not a tard, just moving fast. It's not like we all haven't done a similar thing.


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## NC Plc (Mar 24, 2014)

hardworkingstiff said:


> Also, how often is this compressor cycling on/off? Is the compressor large enough for the shop usage of compressed air?
> 
> One other thing you might try, lower the cutout pressure if the shop can deal with it, that might reduce some of the strain on the motor.


The air compressor sits at 170ish pressure, I put a thing-a-mah-jigger on it that reduced the air line pressure to 80. That's about 30 psi higher than we need for the equipment to operate.

The problem was while the air compressor was rated for continuous duty when it was running 24/7 it was overheating in the storage building. 

The causes of it running 24/7, when it is already larger than the project calls for cfm wise, was a faulty pressure switch and a leak in the air line I have to fix next week.

ALSO, for some ****ing reason it didn't come with a hobs meter on it, and I hate when air compressors do not come with one of those included, so I have to install one tomorrow. They let me know if the compressor is running more than it should so I can sniff out problems.


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## hardworkingstiff (Jan 22, 2007)

I tried to find the motor online and Baldor doesn't seem to recognize L1501T


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## NC Plc (Mar 24, 2014)

hardworkingstiff said:


> I tried to find the motor online and Baldor doesn't seem to recognize L1501T


Same, nothing came up for me.


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## frenchelectrican (Mar 15, 2007)

What frame size and is that motor run 1800 or 3600 ?? Sometime can end up a spl ( specail )rating on them..

I kniw someone mention 50 amp breaker.. That is too small for thst motor it should be at least 80 amps that will give little more current to start up..

Did that motor have thermal protection ??


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## micromind (Aug 11, 2007)

Baldor 1509T = 7.5HP, 3450 RPM, 213T frame, cap start/cap run, no O/L, 30.0 amps.

Baldor 1510T = 7.5HP, 1725 RPM, 251T frame, cap start/cap run, no O/L, 33.0 amps.

When a capacitor blows, it's usually the start one, and very likely because of too many starts per hour or even more likely too long of a starting time. If the voltage is low or the load is high, the motor will cycle in and out of start. This is really hard on start caps, and sometimes happens when a 3Ø motor is replaced with a 1Ø. 1Ø motors do not have as much pull-up torque as 3Ø ones do. 

Check the unloader, if it starts under pressure, a 1Ø model will have a hard time where a 3Ø will be ok. 

How long does it take to come up to speed? Does it come part way up, then sort of cycle a bit then the rest of the way up? 

Generally speaking, caps are designed for not more than 20 starts per hour and not more than 3 seconds per start. 

If known, how long did the capacitor sit before it was installed. If more than a couple of years, it'll need to be reformed before full voltage is applied or it'll blow up after a while. Maybe right away.......


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## telsa (May 22, 2015)

NC Plc said:


> It was a three phase motor and they replaced it with some sort of capacitor run/start single phase motor. Now it's tripping a 50 amp breaker, which is odd to me, and killing capacitors.
> 
> I derped and looked at 3 phase motors haha.


A single phase motor is a TERRIBLE match for this load.

It can't tolerate the incredible number of start-stop-start-stop... to be endured by a compressor loaded motor.

This performance cycle just about demands a three-phase motor.

As a stop gap he must install a separate blower motor to force cool the primary motor whether it's running or not. ( with temperature regulation akin to that found on European automotive radiator fans )

As it stands, it's cooking in its own juice.


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## micromind (Aug 11, 2007)

hardworkingstiff said:


> Is it possible the motor is not cutting out the start capacitor when it should? What effect will that have on the motor?


Bad things will happen......lol.

If the start winding does not disengage, the current will be somewhere near locked-rotor (roughly 6X full-load), it won't come up to full speed, it'll trip the O/L in about 5 - 10 seconds (if properly sized), it might blow the start capacitor and if the O/L or breaker fails to trip, the motor will burn up in less than a minute.


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## RePhase277 (Feb 5, 2008)

How about a hard start kit?


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## frenchelectrican (Mar 15, 2007)

InPhase277 said:


> How about a hard start kit?


It may work with some single phase motors ..

Not all of them can use hard start kit...


For the op.. Ii am thinking some info is missing..

Did you check the supply voltage with compressor offf and check it when it is running .

I do not know what size condductor iit is there.. It should be #8 or larger depending on distance..

Now.. Keep in your mind that some of single phase motor will run on 208 volt network but if a true single phase system it should not go below 220 volts otherwise it will draw more current ..( check the nameplare to see min voltage..)


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## Galt (Sep 11, 2013)

China made capacitors suck . Get some better ones. If a capacitor start capacitor run motor fails to start for any reason the start capacitor will usually be ruined in 10 to 15 seconds the start capacitor normally is taken out of the circuit by a centrifugal switch or a potential relay . Take the end off the motor and examine the switch or sometimes 2 switches wired in series. You can also improve your odds by buying a capacitor with a higher voltage rating. However make sure the microfarad rating is very close to the original. Capacitors do not go bad sitting on the shelf.


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## hardworkingstiff (Jan 22, 2007)

Seems there are a lot of things for the OP to check out.


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## micromind (Aug 11, 2007)

Galt said:


> Capacitors do not go bad sitting on the shelf.


They absolutely do.

Google 'Reforming A Capacitor' and you'll get the idea.


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## te12co2w (Jun 3, 2007)

Thanks for all the replies. Just a few answers now. #8 cu to motor. No load voltage=242. Start up voltage drops to about 229-232, and then recovers quickly. I don't recall current readings exactly, but running amps were right on per motor nameplate. More later. Got new capacitors last night and will be installing them today.


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## NC Plc (Mar 24, 2014)

micromind said:


> They absolutely do.
> 
> Google 'Reforming A Capacitor' and you'll get the idea.


Freezing cold temps kill them too, right?


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## te12co2w (Jun 3, 2007)

hardworkingstiff said:


> You might want to look into the ambient temperature.
> 
> What do the amps look like as the pressure is building in relation to the nameplate rating?


 Once started amps are steady through pressure range.


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## te12co2w (Jun 3, 2007)

joebanana said:


> I think I know what the problem with the capacitors is, "made in China". Probably full of PCB's too.


 That could be a concern. Haven't looked hard for USA made yet.


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## te12co2w (Jun 3, 2007)

hardworkingstiff said:


> Table 430.248 says a single-phase 7.5HP motor at 230V should have a 40A current rating.
> 
> I wonder what the voltage is when the motor is running?
> 
> ...


 I suppose the start cap could be not cutting out, but my experience has shown that if that is the case, the motor would display some signs, such as not coming up to speed.


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## te12co2w (Jun 3, 2007)

NC Plc said:


> Ambient temp caused one of my air compressors to keep tripping its own thermal breakers, had to install a thermostat / exhaust fan / etc just for it.


 I am thinking ambient temp is not an issue. Unheated room, but it stays just above freezing in the coldest of weather. Probably doesn't get too much above outside temp in summer.


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## te12co2w (Jun 3, 2007)

hardworkingstiff said:


> Also, how often is this compressor cycling on/off? Is the compressor large enough for the shop usage of compressed air?
> 
> One other thing you might try, lower the cutout pressure if the shop can deal with it, that might reduce some of the strain on the motor.


 On off cycle might be a factor. I never did time that, but they have a backup compressor that cycles on maybe every 5 to 10 minutes when the shop is closed. I guess they might have some leaks.


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## te12co2w (Jun 3, 2007)

frenchelectrican said:


> What frame size and is that motor run 1800 or 3600 ?? Sometime can end up a spl ( specail )rating on them..
> 
> I kniw someone mention 50 amp breaker.. That is too small for thst motor it should be at least 80 amps that will give little more current to start up..
> 
> Did that motor have thermal protection ??


 I wish you had not asked that question about thermal protection. Wanted to avoid that issue for now but; the motor is probably not thermally protected internally. And they don' have a proper starter on it with overloads. I brought this up and the owners were not wanting to hear about any more expenses. There is a pressure switch (I don't remember the pressure ratings) that energizes a contactor. That's it. Don't shoot me for this. There are no inspection or permits here, so it never got done right in the first place.


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## te12co2w (Jun 3, 2007)

micromind said:


> Baldor 1509T = 7.5HP, 3450 RPM, 213T frame, cap start/cap run, no O/L, 30.0 amps.
> 
> Baldor 1510T = 7.5HP, 1725 RPM, 251T frame, cap start/cap run, no O/L, 33.0 amps.
> 
> ...


 The mechanics say the unloader is working fine. I don't know much about that end of this. Of course the motor starts under some load routinely as regulated by the pressure switch.
Once started it runs until the pressure switch is satisfied. Starts just like it should if the capacitors are good. 
The capacitors was were replaced the the day after I got them. I can't say how long the supplier had them before that.


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## hardworkingstiff (Jan 22, 2007)

te12co2w said:


> ... but they have a backup compressor that cycles on maybe every 5 to 10 minutes when the shop is closed. I guess they might have some leaks.


THIS needs to be fixed (I know it's not what you do and you have no control).


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## hardworkingstiff (Jan 22, 2007)

te12co2w said:


> Once started amps are steady through pressure range.


That seems odd to me (but I have not gone to school for electrical work). I would think as the pressure went up in the tank the motor would have to work harder to do the work which would cause some rise in amperage. 

Am I wrong thinking, and if so, how? Thanks.


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## JRaef (Mar 23, 2009)

I'd think the centrifugal switch is hanging up and not opening all the time. It only takes once to kill the start cap. 

As others have said, a single phase motor sized at 1:1 against a 3 phase motor on a recip compressor is the likely root cause of this. It seems to me (hard to follow) that you said the original design ran all day and loaded/unloaded, then you changed it. That would likely have been hard on the 3 phase motor, let alone changing it to single phase. You have increased the duty cycle of the motor, which is part and parcel to the motor selection process on a recip compressor. Yes, HP is HP, but if you increase the duty cycle, you sometimes have to de-rate the motor size. So you may have needed to go to 10HP even if it was 3 phase, maybe 15 single phase, but that would be a rare motor at that point. Even then, the increased number of starts is still going to take a toll on that centrifugal switch. That's why you rarely see single phase compressors that large.

If its a belt drive, and you don't need as much air as it was originally designed for, you could consider changing the sheave ratio to reduce the load on the motor. That might increase the duty cycle however so because it's a single phase motor, would make it worse. A better plan may be to return to something closer to the original design, run the motor longer and just unload it when not being used. You can add what's referred to as a "minimum run timer" to the pressure switch circuit. It's an off-delay timer controlled by the pressure switch so when the pressure drops, the timer closes, then the timer energizes the starter for the compressor. When the pressure switch opens, it drops out the timer coil, but the timer contacts stay closed for the time value, let's say 10 minutes. After 10 minutes, if the pressure switch is still open, the timer contacts open and drop out the starter. If in that 10 minutes the pressure switch had closed again, the compressor kept running. What this does is minimize the number of start-stop cycles that motor is subjected to.

It will also increase the energy consumption. In reality, that might cost more in the long run than getting a compressor professional to come in and evaluate their needs to give them the correct compressor setup to start with. In a lot of areas, the power utility may even offer a rebate to help offset the cost of that! Here in my area of California, air compressor optimization can get you a nice rebate, sometimes enough to make the cost of changing pay for itself in under a year by the energy cost savings.


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## frenchelectrican (Mar 15, 2007)

te12co2w said:


> I wish you had not asked that question about thermal protection. Wanted to avoid that issue for now but; the motor is probably not thermally protected internally. And they don' have a proper starter on it with overloads. I brought this up and the owners were not wanting to hear about any more expenses. There is a pressure switch (I don't remember the pressure ratings) that energizes a contactor. That's it. Don't shoot me for this. There are no inspection or permits here, so it never got done right in the first place.


I know what yoou mean on that..

Sorry sbout that..

You can get IEC starter with o/l in there . it cheaper than NEMA starter but i do know they have starter for single phase verison.. 

And put smaller pulleey sleeeve on motor side that will help to start up better..


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## te12co2w (Jun 3, 2007)

telsa said:


> A single phase motor is a TERRIBLE match for this load.
> 
> It can't tolerate the incredible number of start-stop-start-stop... to be endured by a compressor loaded motor.
> 
> ...


 Thanks for the input. About the start-stop-start-stop. I guess that makes sense to me, but I did not factor that in.


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## te12co2w (Jun 3, 2007)

micromind said:


> Bad things will happen......lol.
> 
> If the start winding does not disengage, the current will be somewhere near locked-rotor (roughly 6X full-load), it won't come up to full speed, it'll trip the O/L in about 5 - 10 seconds (if properly sized), it might blow the start capacitor and if the O/L or breaker fails to trip, the motor will burn up in less than a minute.


 it'll trip the o/l in about 5-10 seconds (if properly sized). The overloads are not properly sized. In fact they don't even have a proper starter. Every time I mention that, a just get head shakes. That's a work in progress.


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## te12co2w (Jun 3, 2007)

InPhase277 said:


> How about a hard start kit?


 That was one of the things I first thought of. I haven't looked hard, but a short search leads me to believe that a hard start for a single phase, 7.5 hp motor is not easy to find.


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## te12co2w (Jun 3, 2007)

Galt said:


> China made capacitors suck . Get some better ones. If a capacitor start capacitor run motor fails to start for any reason the start capacitor will usually be ruined in 10 to 15 seconds the start capacitor normally is taken out of the circuit by a centrifugal switch or a potential relay . Take the end off the motor and examine the switch or sometimes 2 switches wired in series. You can also improve your odds by buying a capacitor with a higher voltage rating. However make sure the microfarad rating is very close to the original. Capacitors do not go bad sitting on the shelf.


 I would not have considered changing capacitor ratings for fear of smoking the motor, but maybe I will look into that.


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## te12co2w (Jun 3, 2007)

JRaef said:


> I'd think the centrifugal switch is hanging up and not opening all the time. It only takes once to kill the start cap.
> 
> As others have said, a single phase motor sized at 1:1 against a 3 phase motor on a recip compressor is the likely root cause of this. It seems to me (hard to follow) that you said the original design ran all day and loaded/unloaded, then you changed it. That would likely have been hard on the 3 phase motor, let alone changing it to single phase. You have increased the duty cycle of the motor, which is part and parcel to the motor selection process on a recip compressor. Yes, HP is HP, but if you increase the duty cycle, you sometimes have to de-rate the motor size. So you may have needed to go to 10HP even if it was 3 phase, maybe 15 single phase, but that would be a rare motor at that point. Even then, the increased number of starts is still going to take a toll on that centrifugal switch. That's why you rarely see single phase compressors that large.
> 
> ...


 The original design was with a 3 phase motor. One of the mechanic/owners brought the compressor from another state. Plumbed it in and then realized 3 phase was not available. So he bought a single phase motor that would be an easy swap. HP, frame size, shaft size, rpm all the same as the original 3 phase motor. Then someone else wired the compressor motor. That motor lasted a little more than 2 years. Then, one of the start caps blew out. That is where I came in. Replaced both start caps and the single run cap. Things went well for around 2 weeks. Right now I am still waiting for more replacement caps.
This compressor has a switch up in the mechanic bay that controls the coil on the contactor. They turn it off when they quit for the day (supposedly) I know it does not run 24/7 even during business hours. It cycles on the pressure switch. 
I like the idea that a 1:1 swap might not be adequate. That is what I wondered about in the first place. I don't know their air requirements. I did suggest that they could fiddle with different size sheaves to maybe help things out. The owner wasn't real receptive of that idea, and I certainly don't want to spend any more time doing that.
Thanks for the suggestion of "minimum run timer". I'll not suggest that yet.
The local power company does have some rebate programs in place that might help. At one time their policy was to require VFD or soft start technology of motors over 5 hp. I think that was the policy. Didn't want to talk to them about it because then maybe the owners would be forced to spend more money and blame me for their woes.
Long winded, I know. Thanks for your suggestions.


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## te12co2w (Jun 3, 2007)

One more thing. The owner brought up the idea of going back to a 3 phase 7.5 hp motor and then putting a phase converter on it. I haven't followed up on that.

Thanks for all the help!!


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## frenchelectrican (Mar 15, 2007)

te12co2w said:


> One more thing. The owner brought up the idea of going back to a 3 phase 7.5 hp motor and then putting a phase converter on it. I haven't followed up on that.
> 
> Thanks for all the help!!


That can work but if this will be the only 3 ph load you may need one size larger uunit due the starts per hour...


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## hardworkingstiff (Jan 22, 2007)

JRaef said:


> In reality, that might cost more in the long run than getting a compressor professional to come in and evaluate their needs to give them the correct compressor setup to start with.


THAT is the best idea yet.


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## RePhase277 (Feb 5, 2008)

Just for the fun of it, hang an ammeter on the EGC and see if there's any current.


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## NC Plc (Mar 24, 2014)

How much cfm does an air compressor like that generate?

Is it really worth the hassle of all this instead of buying a proper AC like mentioned above?


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## frenchelectrican (Mar 15, 2007)

NC Plc said:


> How much cfm does an air compressor like that generate?
> 
> Is it really worth the hassle of all this instead of buying a proper AC like mentioned above?


If i recall about 18 to 28 depending on pressure..

I know mine 15 hp compressor can kick out about 45 or more cfm ..depending on the pressure it discharge..


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## NC Plc (Mar 24, 2014)

I don't know, if it was my call I would just replace the unit with a single phase one. I know quincy makes a 17cfm ac @ 170 psi for 1300 or so.

Seems like a waste of effort and time. Though, when I make judgement calls about replacing equipment it's always time down troubleshooting vs cost of downtime, with if it's a critical asset or not also considered.


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## frenchelectrican (Mar 15, 2007)

Yuh but make sure that the cusstomer get cast iron compressor they last much longer than the alauinm verison..

That something the customer have to make a choice of keep fix the compresssor or get a new one ...


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## NC Plc (Mar 24, 2014)

Best way to determine if it's cast or aluminum is with a magnet I am guessing?


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## frenchelectrican (Mar 15, 2007)

Yup and if you work around the cast iron just look at cooling fins plus the crankcase..
There is a difference between the two..


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## NC Plc (Mar 24, 2014)

When you say cast vs aluminum which are you referring to? Rotary, piston, etc?


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## Galt (Sep 11, 2013)

A capacitor losing it's charge is not the same as a capacitor failing. When used for motor starting they are quite often discharged with a bleed resistor to stop arcing of the start switch contacts. I do not know their purpose in a vfd but apparently bad things can happen if they lose their charge so they recharge them. they are a very simple component two conductive plates with an insulating material in between. what happens when you hook an ohm meter to the terminals is deceiving They are not conducting current rather the dc battery is stuffing electrons into one plate causing electrons to leave the other plate. Eventually the voltages equal and electrons stop making the ohm meter read very high.


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## micromind (Aug 11, 2007)

NC Plc said:


> How much cfm does an air compressor like that generate?
> 
> Is it really worth the hassle of all this instead of buying a proper AC like mentioned above?


A general rule-of-thumb is 4 CFM per HP at 100 PSI. 

Reciprocating or rotary.


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## micromind (Aug 11, 2007)

In an electrolytic capacitor, there is a thin layer of oxide on the aluminum that is sandwiched between the electrolyte-soaked material. Aluminum oxide doesn't conduct so it insulates itself from the electrolyte, which does conduct. 

With no charge, the electrolyte will dissolve the layer of oxide over time. With no oxide to insulate, when a high-energy charge is applied......boom. 

Reforming involves applying a low voltage low power charge and ramping it up every so often. The time for each step depends on how long the cap has been uncharged. Figure an hour per year of non-use.

The oxide layer will build up when voltage is applied, but it's slow, so voltage needs to be applied slowly or the aluminum will bond to the insulating material and the oxide layer won't form.


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## frenchelectrican (Mar 15, 2007)

NC Plc said:


> When you say cast vs aluminum which are you referring to? Rotary, piston, etc?


Both piston and rotary..

That why the cast iron piston verison is best for hevay duty operatiio
For liight duty the alum will work fiine witth short duty cycle.. ( some may have castt iron sleeve )

For rotary it can be either way as long it have clean lube oil and not get overheated it willl be fine..


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## telsa (May 22, 2015)

frenchelectrican said:


> Yuh but make sure that the cusstomer get *cast iron* compressor they last much longer than the alauinm verison..
> 
> That something the customer have to make a choice of keep fix the compresssor or get a new one ...



Ding. Ding. Ding.

Thread winner.

Further, at this scale, the compressor should be two--stage -- or a helical rotary screw compressor. ( the latter being Kaeser -- yup -- even MORE expensive. )


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## micromind (Aug 11, 2007)

te12co2w said:


> One more thing. The owner brought up the idea of going back to a 3 phase 7.5 hp motor and then putting a phase converter on it. I haven't followed up on that.
> 
> Thanks for all the help!!


I wouldn't recommend this. 

It sounds like the owner is somewhat cheap (they all are.......lol) and would likely buy a static phase converter. A 7 1/2HP 3Ø motor on a static phase converter will produce about 5 HP and very likely wouldn't be able to start the compressor. 

With a rotary phase converter, you'd get about 6 1/2HP and maybe it'd start it, maybe not.


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## te12co2w (Jun 3, 2007)

If he goes with the original 3 phase motor (he said he still has it) and a rotary phase converter, it is suggested by American Rotary to install an ADX-15. If he does that, maybe I'll get a chance to install a proper starter with overloads. Thanks again, all.


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