Phase Converter

[Harry Knutz]

Static converters only provide 3 legs on startup and then go to 2 legs, If you have controls hooked up to the fake leg, It won't work right and all kind of weird stuff happens. That brand converters are not too well regarded.

 

[Chipper5783]

"Don’t use the output of the converter for control purposes.
Use the input voltage"

Forgive my ignorance please. Are you saying the magnetic switch should be on the 220 single phase input side of my converter?

Not really. The power for the magnetic switch should be drawn from the single phase source. The mag switch has a coil that pulls in the main contacts. That coil needs power. Make sure that coil has nice clean power, at the voltage that the coil is designed for. It is very common on machine tools to use a control transformer connected to two terminals of the input (whether single phase, or three phase), then the machine control is done with this reduced voltage (often 120v, sometimes 24v). Some simpler setups will use line voltage for the control power, so no control transformer (I have a table saw like that). The point is that it needs proper control power. Do not take the control power from the added leg out of the phase converter.

1. Check what voltage the mag switch coil is designed for (perhaps a name plate, often a label on the coil itself). If it is rated for the line voltage, you are good.
2. Have a good look at the small wires that connect around the mag switch. They will connect on L1 and L2, or L1 and L3, or L2 and L3. (Perhaps you just need to swap two of the mag contactor input wires). Then you may have to swap your T1/T2/T3 wires around to get the correct motor rotation.
3. You ought to check the current draw on each leg, so as not to be running above the motor nameplate (don’t just crank up the motor overload sensor to see what happens - one of the options is that the magical smoke will come out of the motor - really hard to put it back in).

Let us know how you make out.

 

[Ulma Doctor]

"Don’t use the output of the converter for control purposes.
Use the input voltage"

Forgive my ignorance please. Are you saying the magnetic switch should be on the 220 single phase input side of my converter?

Exactly,
The coil voltage should come from the input, that is switched on and off.
The secondary voltage would come from the output of the phase converter.
The contactor would be switching the output of the phase converter directly to the motor.
With a secondary contactor, and a bit more wiring you could reverse the motor direction , if you see fit.

 

[Ulma Doctor]

The control system must be 220v, as there doesn’t appear to be a transformer

 

[shell70634]

The switch was prewired for 220 and I didn't change it. From all the info, I believe I have the 3 phase wires in the wrong place. I removed the switch completely and the mill ran for 60 seconds or so then popped the 20 amp breaker. If one leg of the converter only provides voltage at startup, then I probably have it wrong. The instructions with the converter just told me to swap wires around until it runs properly.

I'm not fooling with it any more. My son in law has a friend who is an industrial electrician well versed in 3 phase. A case of beer ought to get him here. Cheaper than putting smoke back in the motor.

Thank you for the education and the assistance.

Shelly

 

[woodchucker]

Swapping the wires just changes direction, if it ran on a rotary phase converter then something is wrong with the static phase converter.

 

[Ulma Doctor]

The green wire going to what appears to be an auxiliary contact scares me

 

[Ulma Doctor]

The IEC overload contactors are sensitive and often fail.
You can try to increase the trip potentiometer on the overload contactor to a higher threshold by turning the potentiometer counterclockwise in small increments to see if the overload is causing the trip

 

[shell70634]

The green wire going to a ground.

 

[Harry Knutz]

Swapping the wires just changes direction, if it ran on a rotary phase converter then something is wrong with the static phase converter.

On a static phase converter, Swapping the wires will also figure out which is the false leg. If the false leg is hooked to any controls, It will not work properly, If you swap the wires and then you have a hot going to the controls, It should start working correctly. That's the first thing I would try, You can't screw anything up moving L1, L2 or L3 around.