3 hp VFD, Single Phase 120V Input, 1ph/3ph 220V Output

The braking resistor used in this VFD model EM15-SP1S1-2d2 is 100w/70Ω.

The braking resistor is connected to the P+/PB terminal.

VFD displays error code 40, which means The load is too heavy or locked- rotor occurs on the motor. Also, The frequency inverter model is of too small power class. If the VFD can run normally after removing the motor, it means that your motor load is too heavy and the VFD is overloaded. We recommend that you replace it with a VFD with a 5HP capacity.

Please follow the steps below to troubleshoot and provide us with feedback:
1. Since your motor has dual voltage 230V/460V, please confirm that your motor wiring is based on low voltage 230V.
2. Please check whether the VFD input voltage is 120VAC?
3. Please tell us what parameters are set in the VFD, especially whether the parameters F1-01~F1-04 are set according to the motor nameplate?
4. Please confirm that the VFD and motor are connected correctly and set the correct parameters, then run the VFD again and provide us with a start-up video for confirmation

You can refer to our setup instructions first, and if you have other questions after receiving the goods, please contact us.
Manual: https://www.ato.com/Content/doc/110V-120V-input-VFD-user-manual.pdf

This is a problem with the characteristics of the single-phase motor itself, so we do not recommend that the single-phase motor run for a long time at low frequency and low speed, otherwise the motor capacitor will heat up. Because the starting capacitor of the single-phase motor is only used to assist the motor to start. If the motor runs at low speed for a long time and the centrifugal switch is not disengaged, it will cause heat damage to the motor. If you want the motor to run at low frequency and low speed, we suggest you use a three-phase motor, or you can try to change the internal winding circuit of your single-phase motor to three-phase wiring and remove the capacitor.

The problem you mentioned is probably caused by the over load current driven by the motor is huge, and then the input voltage and bus bar voltage to be low. You can try to set F0-10=60, F0-12=60, F0-17=10, F0-18=10, then rerun the VFD and test again. When the VFD is running, you can switch the shift key >>U0-03 & U0-04, to see the voltage and current output from the VFD real-time. If the VFD cannot working properly, you may need to replace a larger capacity VFD.

We recommend to use the drive with motors only. And yes, the output voltage is variable.

For our 1-phase To 3-phase drive, no need to oversize, we care about that in design, just consider 10% margine above rated output current referred at each model seen at our web site.