connecting only one cap is good as well but don't use 3th phase in that case. Well start motor find cap for 2 nd phase that rises power disconnect it and then find cap fo 3th phase that rises power and then connect both caps respectively . Try to connect caps in parallel to those caps and find if it helps. Even if the voltage on phases is lover you still can force the nominal current and it will not burn coils but for 120 and 240 degree shift phase current must be lower then in 1st phase.
wow man thanks for the lesson!, I gotta copy this down and read through it a bit more!
I knew about using one run cap (I didn't have one big enough on the day) but not two!
I will build a RPC soon as I get my hands on a big 3 phase motor but being able to make a box to plug these compressors into single phase power would be better!
Bigger cap e.g. 20 to 80 uF micro farads in series with 2nd phase therefore grid for that must be higher then 240v and from 10 to 40 uF for 3th phase here grid must be even higher. Since voltage higher then 240v might be a problem 2nd and 3th phase can not be used with full power they can only help. caps must be different if they are the same there is simply short thru 2nd and 3th phase because magnetic fields interact just like in badly connected transformer.
caps are simple way to avoid generator converter but caps depend on motors. So power is divided . On only 240v 1st phase can do 1/3 power , 2nd less then that and 3th the least due to voltage drop on caps but it is increase in power. My advice for the easiest way. Current measured in all phases must be the same as in 1st phase connected to 240v grid. voltage drop from ground to each phase must be 240v. On 1st that is obwious it is the grid but on 2nd and 3th it goes in series with caps.
Measure current in all phases in the 1st normal one it will be the highest on 240v only. when you use 240v for 1 phase and 350v for 2nd and 3th phase it is possible to make current in 2nd phase equal to 1st phase but 3th phase must be lower or use even higher voltage for only 3th phase. Well the 3th phase must have lower capacitor than 2nd in order to hold different phase shift. Motor is winded in such a way that magnetic fields need this phase shifts.
Sometimes on 1phase motors with capacitors (2phase motors actualy) they use second for short time, capacitor in parallel with first cap to increase starting power. What happens the phase shift on 2nd winding slightly shifts e.g. from 90 degrees to 105 degrees nothing wrong with that but the current in 2nd winding goes few times up and create strong magnetic field , of course it would burn winding in long run. So small capacitance does nothing and big makes current go too high. Measure the curent
transformer that have 110v on output, go ahead and connect secondary in series with primary. In phase you have 350v in no phase 130v so add or substract. power is higher than nominal because 2/3 (66%) goes directly from grid (240v) and 1/3 (33%) goes from transformer thru magnetic core. So for 1000w transformer you can step up to 350v and draw 3000w .What happens above 3000w? well voltage goes from 350v to 240v and grid limits the power so it is great power source. it is autotransformer setup.
In 1phase motor the run capacitor creates 2nd phase in 90 degrees shift so in reality they are all 2phase motors. You have to do similar thing with 2nd and 3th phase in 120 degrees shift and 240 degrees shift respectively. Of course on 1phase motors the artificial second phase has winding for lower voltage so this is the reason why you can only partly simulate 2nd and 3th phase. In theory you would use voltage higher then 240v e.g. 350v and higher ratings for caps.
Use two others capacitors with different capacitance to simulate the 2nd and 3th phase. It will increase power and stability. Of course three things. 1 It is not the real 3phase because voltage on 2nd and 3th phase coil is lower than 240v. 2 capacitors will be close to resonance so the voltage on capacitors will go as high as 400v and higher so they must be rated at that. 3 capacitance depends on current and inductance in coils while running so you have to experiment. Discharge caps after tests!
I'm thinking the high pressure on the discharge side forces the oil to work its way back into the crank case instead of out the discharge under normal conditions.
running them with zero pressure on the discharge side would prevent that, and cause them to dump oil out the discharge perhaps.
Just a theory though. if they were to dump their oil like that it would get trapped in the accumulator and run them dry, so it must get back internally somehow.
I guess thats the reason why some AC compys discharge into the compressor casing before it goes to the condenser coil. Using the casing itself as an oil trap. Just for a thought.
Nice video !
Thanks,
kris.
krisachar 1 year ago
I work for the company that makes these compressors. So seeing this video is very weird for me lol.
LieutenantFaceStab 2 years ago
nice doom music, doom1 or 2 i dont remember, i think its from doom1 :P
Kingratass 2 years ago
I think its Doom1, can't remember the name of it though.
Aussie50 2 years ago
great I'd like to know the wiring diagram for this, sure would make a kick ass air compressor
HDXFH 2 years ago
Indeed!, I'll have to work on this. I shot the video ages ago just after I scrapped the unit then shelved them.
I'll get into it soon
Aussie50 2 years ago
connecting only one cap is good as well but don't use 3th phase in that case. Well start motor find cap for 2 nd phase that rises power disconnect it and then find cap fo 3th phase that rises power and then connect both caps respectively . Try to connect caps in parallel to those caps and find if it helps. Even if the voltage on phases is lover you still can force the nominal current and it will not burn coils but for 120 and 240 degree shift phase current must be lower then in 1st phase.
wwyyllyy 2 years ago
wow man thanks for the lesson!, I gotta copy this down and read through it a bit more!
I knew about using one run cap (I didn't have one big enough on the day) but not two!
I will build a RPC soon as I get my hands on a big 3 phase motor but being able to make a box to plug these compressors into single phase power would be better!
again, thanks for the info!
Aussie50 2 years ago
Bigger cap e.g. 20 to 80 uF micro farads in series with 2nd phase therefore grid for that must be higher then 240v and from 10 to 40 uF for 3th phase here grid must be even higher. Since voltage higher then 240v might be a problem 2nd and 3th phase can not be used with full power they can only help. caps must be different if they are the same there is simply short thru 2nd and 3th phase because magnetic fields interact just like in badly connected transformer.
wwyyllyy 2 years ago
caps are simple way to avoid generator converter but caps depend on motors. So power is divided . On only 240v 1st phase can do 1/3 power , 2nd less then that and 3th the least due to voltage drop on caps but it is increase in power. My advice for the easiest way. Current measured in all phases must be the same as in 1st phase connected to 240v grid. voltage drop from ground to each phase must be 240v. On 1st that is obwious it is the grid but on 2nd and 3th it goes in series with caps.
wwyyllyy 2 years ago
Measure current in all phases in the 1st normal one it will be the highest on 240v only. when you use 240v for 1 phase and 350v for 2nd and 3th phase it is possible to make current in 2nd phase equal to 1st phase but 3th phase must be lower or use even higher voltage for only 3th phase. Well the 3th phase must have lower capacitor than 2nd in order to hold different phase shift. Motor is winded in such a way that magnetic fields need this phase shifts.
wwyyllyy 2 years ago
Sometimes on 1phase motors with capacitors (2phase motors actualy) they use second for short time, capacitor in parallel with first cap to increase starting power. What happens the phase shift on 2nd winding slightly shifts e.g. from 90 degrees to 105 degrees nothing wrong with that but the current in 2nd winding goes few times up and create strong magnetic field , of course it would burn winding in long run. So small capacitance does nothing and big makes current go too high. Measure the curent
wwyyllyy 2 years ago
transformer that have 110v on output, go ahead and connect secondary in series with primary. In phase you have 350v in no phase 130v so add or substract. power is higher than nominal because 2/3 (66%) goes directly from grid (240v) and 1/3 (33%) goes from transformer thru magnetic core. So for 1000w transformer you can step up to 350v and draw 3000w .What happens above 3000w? well voltage goes from 350v to 240v and grid limits the power so it is great power source. it is autotransformer setup.
wwyyllyy 2 years ago
In 1phase motor the run capacitor creates 2nd phase in 90 degrees shift so in reality they are all 2phase motors. You have to do similar thing with 2nd and 3th phase in 120 degrees shift and 240 degrees shift respectively. Of course on 1phase motors the artificial second phase has winding for lower voltage so this is the reason why you can only partly simulate 2nd and 3th phase. In theory you would use voltage higher then 240v e.g. 350v and higher ratings for caps.
wwyyllyy 2 years ago
Use two others capacitors with different capacitance to simulate the 2nd and 3th phase. It will increase power and stability. Of course three things. 1 It is not the real 3phase because voltage on 2nd and 3th phase coil is lower than 240v. 2 capacitors will be close to resonance so the voltage on capacitors will go as high as 400v and higher so they must be rated at that. 3 capacitance depends on current and inductance in coils while running so you have to experiment. Discharge caps after tests!
wwyyllyy 2 years ago
cool.
V8Jagnut 2 years ago
Perhaps some kind of oil separator on the output that moves the oil back into the suction side?
amfan12 2 years ago
I'm thinking the high pressure on the discharge side forces the oil to work its way back into the crank case instead of out the discharge under normal conditions.
running them with zero pressure on the discharge side would prevent that, and cause them to dump oil out the discharge perhaps.
Just a theory though. if they were to dump their oil like that it would get trapped in the accumulator and run them dry, so it must get back internally somehow.
Aussie50 2 years ago
I guess thats the reason why some AC compys discharge into the compressor casing before it goes to the condenser coil. Using the casing itself as an oil trap. Just for a thought.
DragonFlyback256 2 years ago
yeah, the rotary compressors discharge a lot less oil than these!.
I think back pressure helps a lot in the scrolls, forcing oil down into the low pressure crank case.
Aussie50 2 years ago