I performed a number of experiments on my 4 ton scroll compressor.

it works great as an RPC, similar in impedance to a 5-6 hp 3 phase motor.

The run winding is connected across the 120/240v line and the auxiliary winding is connected to the neutral.

A 50uF capacitor is connected from the other end of the aux winding to the 120v line.

It self starts with the 50uF capacitor, and open circuit is 240 volts across the auxiliary winding with 4.5 amps flowing through the neutral (due to the 50uf cap). voltage across the capacitor is 270 vac, voltage from the third leg to the other 120v line is 265 when the mains are at 250 volts. so the open circuit 3 phase voltage is 250/265/270 volts.

The input current is 9.6 amps, and 11.2 amps. (with the capacitor removed these would both be about 16 amps, and the auxiliary coil would generate 225 volts instead of 240)

When the rpc is loaded with a 16 ohm resistor connected across the auxiliary coil, the voltage drops from 240 to 207 volts*, 12 amps flow into the resistor or about 2500 watts.

The input current increases from 9.6 to 18.6 amps, and from 11.2 to 16.7 amps. the current flowing through the neutral decreases from 4.5 to 3.9 because the voltage across the capacitor decreases from 270 to ~240 volts.

I placed a magnet on the shaft and at no load it takes 34 seconds for the rotor to fall behind 1 revolution. so its running at about 3598 rpm.

When the load is placed on the rpc the rotor takes 13 seconds to lag behind 1 revolution. or about 5 rpm short of 3600. this is a lot less slip than i expected. i can repeat the test again with a heavier load later.

*(207 is what it should be for 240/240/240/208 3 phase)

it works great as an RPC, similar in impedance to a 5-6 hp 3 phase motor.

The run winding is connected across the 120/240v line and the auxiliary winding is connected to the neutral.

A 50uF capacitor is connected from the other end of the aux winding to the 120v line.

It self starts with the 50uF capacitor, and open circuit is 240 volts across the auxiliary winding with 4.5 amps flowing through the neutral (due to the 50uf cap). voltage across the capacitor is 270 vac, voltage from the third leg to the other 120v line is 265 when the mains are at 250 volts. so the open circuit 3 phase voltage is 250/265/270 volts.

The input current is 9.6 amps, and 11.2 amps. (with the capacitor removed these would both be about 16 amps, and the auxiliary coil would generate 225 volts instead of 240)

When the rpc is loaded with a 16 ohm resistor connected across the auxiliary coil, the voltage drops from 240 to 207 volts*, 12 amps flow into the resistor or about 2500 watts.

The input current increases from 9.6 to 18.6 amps, and from 11.2 to 16.7 amps. the current flowing through the neutral decreases from 4.5 to 3.9 because the voltage across the capacitor decreases from 270 to ~240 volts.

I placed a magnet on the shaft and at no load it takes 34 seconds for the rotor to fall behind 1 revolution. so its running at about 3598 rpm.

When the load is placed on the rpc the rotor takes 13 seconds to lag behind 1 revolution. or about 5 rpm short of 3600. this is a lot less slip than i expected. i can repeat the test again with a heavier load later.

*(207 is what it should be for 240/240/240/208 3 phase)

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