View Full Version : VFD gurus. A question
11-13-2011, 03:13 PM
Changed over to VFD's on the lathe and mill this weekend. The lathe is like a new machine. I've got high speed back on the motor and all the other stuff these little boxes offer. The lathe has a 1970's motor and was very happy from the conversion. It runs better than than ever. It truly is a new machine.
The mill is from 1965. Motor would not run above 5Hz. (TECO 7300EV series controller. one HP motor) So I'm playing around and turn off "acceleration stall prevention". Motor spins up, works correctly, but makes some nasty sounds for 3 seconds or so. Sounds like bearings rattling or could be the armature arcing out. It does this intermittently. About every third start. If I shut down while all this nasty noise is going on, the controller will still run the motor until it reaches frequency, then shut off.
Any other permitters I should check out?
It's my luck. The lathe ran bad on the RPC, but the mil ran sweet. Now it's the other way around.
Thanks for the help in advance.
11-13-2011, 03:48 PM
About every third start. If I shut down while all this nasty noise is going on, the controller will still run the motor until it reaches frequency, then shut off.
What do you mean by 'you shut the motor down the controller will still run the motor? Do you have any alarm code when it shuts off?
11-13-2011, 04:11 PM
The controller will not shut down immediately. It wants to reach the frequency that it was set to, then it will shut off. The motor will make make these nasty sounds, VFD shows the frequency bouncing around for about 3 seconds till the motor starts running normal then the VFD will shut off.
11-13-2011, 04:28 PM
If it is shutting down for ANY reason, there should be an error code on the display?
11-13-2011, 04:32 PM
The TECO 7300 is a sensorless vector drive. I assume that you are using it in that mode. Have you run set the mill motor parameters and/or run the auto tuning routine (0-06)?
When you say the mill motor would not run above 5 Hz I assume you mean that it would not accelerate through 5 Hz?. I would check the basic motor parameters that you should find on the motor itself and ensure that the VFD is correctly set using the functions 0-00 - 0-07.
11-13-2011, 05:19 PM
It will accelerate beyond 5 Hz after turning off the stall prevention, Just makes nasty sounds on start up, regardless of speed.
Re checked motor requirements.Could not find the tuning mode other than PID. that didn't help.
11-13-2011, 05:31 PM
VFDs don't always work with dual speed motors, there should be no switchgear between the VFD & Motor,
11-14-2011, 11:02 AM
The auto tuning mode is at 0-06. PID is whole different set of issues and probably not relevant. See below for options from the manual (formatting lost)
0- Drive Operation Mode
Code No. LCD Display Description Range/Code Factory
0-00 (Control Mode) Control Mode
0000: Vector (General Purpose)
0001: Vector (Variable Torque)
0002: Volts/Hz (Refer to Parameter
Group 10- Volts/Hz Mode)
0-01 (Motor Rated Volt) Motor Rated Voltage (Vac) ----- *3*5
0-02 (Motor Rated Amp) Motor Rated Current (Amp) ----- *3*5
0-03 (Motor Rated KW) Motor Rated Power (kW) ----- *3*5
0-04 (Motor Rated RPM) Motor Rated Speed (RPM) ----- *3*5
0-05 (Motor Rated Hz) Motor Rated Frequency (Hz) ----- *3*5
0-06 (Auto Tuning) Motor Parameter Auto Tuning
0-07 (AC Input Volt) AC Line Input Voltage (Vac)
0-08 (Select Language) Language Selection
Only for LCD keypad
Do you have the full manual? If not you should download it.
11-14-2011, 11:58 AM
Thanks for all the help.
I have the full manual. All the codes in it start with an "F-0" or "C-0"
On this one the default is Vector mode. It has a setting to switch this to "V/f"
I did find some areas in codes F43 thru F50 for entering motor information. I'll reset it and try that tonight after work.
An update, Just got off the phone with the tech guy at Teco. When I discribed it to him, he thinks the drive is defective and is sending single phase to the motor. I had left this out, but I did notice the motor just didn't seem to run quite as smooth as before.
11-14-2011, 12:28 PM
My apologies. I looks like I am misleading you. The TECO 7300 EV is different to other 7300 models and does not appear to have the commands that I describe. I can only assume that no motor tuning is necessary for this model. However you should still check that the motor parameters F43-F46 are reasonable from the plate on the motor.
11-14-2011, 06:40 PM
Connect the mill motor to the the lathe vfd. Does it run correctly?