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Used rotary phase converter???

Joeblough

Plastic
Joined
Jan 13, 2020
I am new to this forum and admittedly I don’t know as much about hooking up phase converters as I should for attempting a project like this. Regardless, I bought a 10 Hp Siemans rotary phase converter that supposedly worked. I hooked it up the best I could and got the motor to start when I flip the breaker, but the “switch” or Contactor on the top right arcs and then the motor shuts off after a brief period. I know I must have something wrong but I am over my head. Attached are a sketch I made, and a couple pictures of the current situation. Any advice would be greatly appreciated. Thank you in advance02EDB055-A638-41FA-B347-3E5A7091AC62.jpg925B1691-7BF4-4CC7-830A-F0CB2E0B18BD.jpgA067233F-0D20-4AFE-9422-8781E8DC0054.jpg

Below is the link for full size pictures

Album — Postimage.org
 
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What you describe sounds like a protection device is shutting down the motor. Likely a motor overload that is monitoring current.

With that guess I think you should try to get a model number or a better diagram. If the pictures cannot be made larger then get the component
numbers and list them.
 
Perhaps a shot of whatever passes for a data plate on the thing?

Mine I bought used, but it is a very very simple ARCO rotary, with no contactors, one capacitor that does not need to be disconnected. I have one contactor to start it up and it just works.

Simple is good, and reliable.

That said, you may have a simple problem. Wrong voltage, bad capacitor, etc.

Does t start up quickly? Or take some time? Slow may mean a bad cap, and is apt to trip overloads. I saw two things labeled capacitor, but it is not clear which is the start and which the run cap.

Is the one you labeled 1 or theone you labeled 2 the start cap? If that is not clear, is one a black plastic thing and the other a metal cased part? It looks as if that is true, but not clear which is what.
 
It starts immediately when the breaker is flipped. I am not sure which one is the start capacitor, but the capacitor 1 is metal and capacitor 2 is plastic. I will try to make the pictures clearer
 
1. The metal case capacitor is a run capacitor.
2. The black plastic case capacitor is a start capacitor.
3. The device in the upper right is a relay used to connect the start capacitor.
4. The device below the relay is a timer which is used to switch the relay on and off.
5. The Dayton timer has a little delay period adjustment at the upper left. You can turn that to adjust the on time. I can only see a "2" marked on it. It might be ".2".
6. In the circuit diagram the lines cross over one another. If there is a connection where wires cross then emphasize that with a dot. Or make a half circle over the wire to show that the two wires are not connected.

The first thing you should do is check that the relay is only being energized by the timer for a short time like 1/2 second. You can easily see that by watching the
contact arm move up and down. If it doesn't move or it only moves in one direction then that is a problem.
 
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the “switch” or Contactor on the top right arcs and then the motor shuts off after a brief period.

1. How many seconds is that brief period?
2. When the motor shuts off is the main power breaker disconnecting? I would guess that the breaker is removing power because it is undersized.
3. You see that spark because the start capacitor does not have a bleed resistor and has a full charge that sparks through the relay contacts.
 
Alternately, the start cap may never be disconnected automatically with the current wiring.

It needs to be.

The question was not which SHOULD BE the start cap, but which one ACTUALLY IS connected as the start cap. But if it starts up OK, that is probably correct.

However, if the cap does not get disconnected, due to jammed or stuck contactor, bad wiring, etc, the unit will pull lots of current and will shut down just as you say, and probably with a substantial spark,
 
The motor runs for about 4-5 secs before a loud pop and the motor shuts down without tripping the 40 Amp breaker. Probably some sort of overload protection in the motor. It won’t start immediately after, but after sitting will do the same thing.
 
Alternately, the start cap may never be disconnected automatically with the current wiring.

It needs to be.

The question was not which SHOULD BE the start cap, but which one ACTUALLY IS connected as the start cap. But if it starts up OK, that is probably correct.

However, if the cap does not get disconnected, due to jammed or stuck contactor, bad wiring, etc, the unit will pull lots of current and will shut down just as you say, and probably with a substantial spark,


——-good advice and sounds like this might be the problem. Do you have any suggestions as to how to separate the starting capacitor in my system as I am not really sure how to do it properly.
 
I am new to this forum and admittedly I don’t know as much about hooking up phase converters as I should for attempting a project like this. Regardless, I bought a 10 Hp Siemans rotary phase converter that supposedly worked. I hooked it up the best I could and got the motor to start when I flip the breaker, but the “switch” or Contactor on the top right arcs and then the motor shuts off after a brief period. I know I must have something wrong but I am over my head. Attached are a sketch I made, and a couple pictures of the current situation. Any advice would be greatly appreciated. Thank you in advanceView attachment 275373View attachment 275374View attachment 275375

Below is the link for full size pictures

Album — Postimage.org

My best guess, its not large enough of a capacitor and overloading one phase over the rest. probably causing a large voltage drop and a bunch of heat, try a smaller hp rotary motor.
 
Thanks for the help. I installed a regular household switch on the wire between the start capacitor and the relay. When I flip the breaker it buzzes and I flip the switch, the motor starts. Then flip the switch off and the motor stays running and runs my jointer just fine. In the near future I will install a monetary switch in the household switch’s place and also will put a 220 switch on the box so I don’t have to run to the breaker box and back to the converter to start. Thank you
 
Sounds like the relay is in fact not releasing. That may be due to it being stuck, or due to the (probably somewhere in there) voltage relay not releasing the capacitor relay when the RPC has come up to substantial voltage.

It will be best to use a contactor of suitable rating to switch the capacitor. If the existing one seems OK, operating OK when you just push the contacts by hand, then it may be whatever supplies the control signal.

You can put in your switch to operate the contactor. Reason to do that is, contactors are rated for the high current of a motor start, and most commonly available switches are not, although they will easily handle the relay coil current.*
You may want to investigate the existing contactor/relay and see if it is jammed. If it seems to operate OK, then use your new switch to apply control voltage to it. At your leisure, cut [power to the thing and check out to see that there is a voltage relay etc. It is hard to tell from the small pics.

* A 10 HP 230V motor can draw 50A under load, and over 200A during start for a short time... Most any regular switch will NOT handle that, but contactors rated for 10HP have to and are made to..
 
As info, I installed a 30 amp double pole switch on the input single phase side and a momentary switch on between the run and start capacitor

E2808143-2813-448F-8668-BC0BC3F0EA81.jpg
 
If your switch has an appropriate HP rating, then you are fine.

Otherwise, maybe not..... the HP rated switches have large short term overload capability, the current rating is not what you use, When you have a current rated switch, the motor should not pull much over 1/4 of the rating. The remainder may be OK as an overload, but the motor may pull as much as 8x FLA. Check the code on the motor, which gives the "locked rotor amps".
 








 
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