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1HP Bridgeport, low power using VFD for RPM
- Thread starter Janderso
- Start date
I have two of those Teco FM50 VFDs. Running the motor at 60 Hz should give you full HP. Select spindle RPM with your pulleys. This should give your full power.
Sometimes you can get away with leaving the belt/pulleys alone and just vary the VFD, but sometimes you can't especially in a non-vector rated motor like these old Bridgeport motors. Running at lower Hz can cause overheating and loss of power/torque.
Monitor how hot your motor gets while working as well. If you put your hand on it and it's getting really hot, I would up the Hz to 60 (not much over) and keep it there so things will cool off and run the way the motor is designed. Use the step pulleys for big variance in spindle RPM and stay fairly close to 60 Hz in these old motors.
Just my two cents,
Ted
Sorry,
I have no idea. I do have the manual on the VFD. I am so limited when it comes to anything electrical.
My son works for a commercial electrical contractor, but he does not get involved in motors or machine wiring.
Hi Jim,
If you look on the side of the motor you should see a label indicating the two possible configurations of the motor. Now if you look inside the motor connecting box you should see jumpers on the terminals. Those jumpers correspond to the label. Please make sure that you remove the power to the motor before looking in the connecting box.
Somewhere I have a picture showing the label. I'll post it if I can lay my hands on it.
If you look on the side of the motor you should see a label indicating the two possible configurations of the motor. Now if you look inside the motor connecting box you should see jumpers on the terminals. Those jumpers correspond to the label. Please make sure that you remove the power to the motor before looking in the connecting box.
Somewhere I have a picture showing the label. I'll post it if I can lay my hands on it.
There are no terminals on this motor like a European motor. In this case this is either a 9 lead motor if it is a 230/460 dual voltage, or if 230V only, has 3 leads for the input connection. Bridgeport used both motor types. You don't have a choice to connect Y or Delta.
Hello Jim,
Thank you for the information.
I do apologize, I had no idea that the USA market had different motor configurations. I've only ever had experience with the dual voltage motors.
I posted that information based on experience with people that wired in a VFD without changing the motor to delta and suffered loss of power.
To Janderso, I'm sorry if I mislead you ! I was unaware of a single voltage Bridgeport motor.
Thank you for the information.
I do apologize, I had no idea that the USA market had different motor configurations. I've only ever had experience with the dual voltage motors.
I posted that information based on experience with people that wired in a VFD without changing the motor to delta and suffered loss of power.
To Janderso, I'm sorry if I mislead you ! I was unaware of a single voltage Bridgeport motor.
In doing some research I did find a diagram to connect a 9 lead motor as delta, so it may be possible. But I have never seen that connection diagram on any low horsepower motor data plate.
To really get low speed performance out of a VFD driven motor, you need a sensorless vector VFD. With that you get 100% torque down to near 0 RPM. That gives you constant torque below the base speed, and constant HP above base speed.