Advanced Troubleshooting - PENN Controls - VFD68Bxx - VFD68Cxx - VFD68Dxx - Three‐Phase Motor Speed Controller - VFD68 Three‐Phase Variable Frequency Drive

VFD68 Variable Frequency Drives Technical Bulletin

Product name
VFD68 Three‐Phase Variable Frequency Drive
Document type
Technical Bulletin
Document revision
C
Revision date
2019-08-09

Use the following tables to resolve problems with the VFD68 drive.

Table 1. Symptoms and Resolutions
Symptom Resolution Table
Motor Does Not Start Table 2
Motor or Machine Makes Generates Acoustic Noise Table 3
VFD Generates Abnormal Acoustic Noise Table 4
Motor Generates Heat Abnormally Table 5
Motor Rotates in the Opposite Direction Table 6
Speed Greatly Differs from the Setting Table 7
Acceleration/Deceleration Is Not Smooth Table 8
Speed Varies During Operation Table 9
Operation Mode Cannot Be Changed Table 10
Operation Panel Display Does Not Operate Table 11
Motor Current is Too Large Table 12
Unable to Write Parameter Setting Table 13
Table 2. Motor Does Not Start
Check Points Possible Cause Action
Main Circuit Appropriate power supply voltage is not applied.

(Operation panel display is not provided.)

Power ON moulded case circuit breaker (MCCB), an earth leakage circuit breaker (ELB), or a magnetic contactor (MC).
Check for the proper input voltage, input phase loss, and wiring.
Motor is not connected properly. Check the wiring between the VFD and the motor.
The jumper from terminal P/+ to terminal P1 (on VFD68Bxx and VFD68Cxx models) or from terminal P to terminal P1 (on VFD68Dxx models) has been removed. Connect a jumper from terminal P/+ or terminal P to terminal P1.
Input Signal Analog input signal is not enough to start the motor. Check for proper voltage on analog inputs.

Verify that the PU and EXT LEDs are illuminated.

Terminal STR is connected to terminal SD. Disable the STR feature by setting P. 78 = 1. Connect terminal SD to terminal STF to run the motor in the forward direction.
Frequency command is zero.

(RUN LED on the operation panel is flickering.)

Check the frequency command source and enter a frequency command.
SINK-SOURCE jumper is set incorrectly.

(RUN LED on the operation panel is flickering.)

Check that the control logic switchover jumper connector is installed in the SINK position:

If it is not installed correctly, input signal is not recognized.

Jumper wires between S1 and SC, S2 and SC are disconnected (VFD68Bxx and VFD68Cxx models only). Verify that jumper wires connect together terminals S1, S2, and SC.
Voltage/current input switch is not correctly set for analog input signal (0 to 5 V or 0 to 10 V,4 to 20 mA) (VFD68Bxx and VFD68Cxx models only).

(RUN LED on the operation panel is flickering.)

Set P. 73, P.266, P.267, and a voltage/current input switch correctly, then input an analog signal in accordance with the setting.
Param. Setting Motor Speed vs. Pressure (C 2 to C 7) settings are improper. Check the Motor Speed vs. Pressure (C 2 to C 7) calculations and settings.
Load Load is too heavy. Reduce the load.
Shaft is locked. Inspect the machine (motor).
Others Operation panel display shows an error (E.OC1). When any fault occurs, take an appropriate corrective action, then reset the VFD, and resume the operation.
Table 3. Motor or Machine Generates Abnormal Acoustic Noise
Check Points Possible Cause Action
Param. Setting Resonance occurs (mechanical system resonance frequency)
  • For Frequency Jump 2, set P. 33 and P. 34.
  • For Frequency Jump 3, set P. 35 and P. 36
When it is desired to avoid resonance attributable to the natural frequency of a mechanical system, these parameters allow resonant frequencies to be jumped.
Resonance occurs (carrier frequency) Change P. 72 setting.

Changing the PWM carrier frequency can reduce the audible noise created when the motor is running at speeds slower than the maximum rated speed (see PWM Frequency, Audible Motor Noise, and EMI).

Others Mechanical looseness Adjust machine/equipment so that there is no mechanical looseness.
Motor Operating with output phase loss Check the motor wiring. Contact the motor manufacturer.
Table 4. VFD Generates Abnormal Acoustic Noise
Check

Points

Possible Cause Action
Fan The fan cover was not correctly installed when a cooling fan was replaced. Install the fan cover correctly.
Table 5. Motor Generates Heat Abnormally
Check

Points

Possible Cause Action
Param. Setting The fan motor is running too slowly to create airflow. Verify that P. 31 is set to 0 and P. 32 is set to 12.5 Hz. If 12.5 Hz is too slow, increase frequency for
  • P.32, C 2, C 5 (VFD68Bxx and VFD68Cxx models)
  • P.32, P.902a, P.904a (VFD68Dxx models).
Motor The fan motor is not working (dust is accumulating.) Clean the motor fan.

Improve the environment.

Phase to phase insulation of the motor is insufficient. Check the insulation of the motor.
Main Circuit The VFD output voltage (U, V, W) are unbalanced. Check the output voltage of the VFD.

Check the insulation of the motor.

Table 6. Motor Rotates in the Opposite Direction
Check

Points

Possible Cause Action
Main Circuit Phase sequence of output terminals U, V and W is incorrect. Connect phase sequence of the output cables (terminals U, V, W) to the motor correctly
Table 7. Speed Greatly Differs From the Setting
Check

Points

Possible Cause Action
Input Signal Analog input device is not creating the proper analog signal. Measure the input signal level.
The analog input signal lines are affected by external EMI. Use shielded wire for the low-voltage analog inputs and route the wiring away fromhigh-voltage wiring. Connect shields to VFD terminal 5. If EMI still affects the control or the VFD, then install a ferrite core (such as TDK P/N: ZCAT3035-1330) on the analog input wiring.
Param. Setting Torque Boost or Maximum Speed settings are improper. Check the settings of P. 1 and P. 2.
Motor Speed versus Pressure Ramp settings are improper. VFD68Bxx and VFD68 Cxx: Check the C 2 to C 7 settings.

VFD68Dxx: Check the P.905 to P.905 settings.

P. 32 setting is incorrect. Determine the best minimum motor speed needed before the motor shuts off and use that value for P. 32.
Table 8. Acceleration/Deceleration is not Smooth
Check

Points

Possible Cause Action
Param. Setting Acceleration/deceleration time is too short or too long. Change P. 7 and P. 8 values.
Table 9. Speed Varies During Operation
Check

points

Possible Cause Action
Input signal The analog input signal lines are affected by EMI. Use shielded wires for the low-voltage analog input signal lines. Route the wiring away from high-voltage wiring. Connect shields to VFD terminal 5. If EMI still affects the control or the VFD, then install a ferrite core (such as TDK P/N: ZCAT3035-1330) on the analog input wiring.
Param. Setting The power supply voltage fluctuates too much. Change the P. 19 setting to the voltage rating on the controlled motor.
Table 10. Operation Mode Cannot Be Changed
Check

Points

Possible Cause Action
Input Signal Start signal is enabled (terminal STF is connected to terminal SD). Check that a jumper is not connecting the STF and SD terminals. If the jumper is connected, the operation mode cannot be changed.
Table 11. Operation Panel Display Malfunctions
Check

Points

Possible Cause Action
Display The operation panel display malfunctions. Contact PENN by Johnson Controls Application Engineering at 1-414-524-5535 or 1-800-275-5676.
Table 12. Motor Current is Too Large
Check

Points

Possible Cause Action
Load The fan motor stalls and error code OL appears on the display. Ensure that combination of motors connected in parallel does not exceed the VFD68 drive’s output current rating.
Table 13. Unable to Write Parameter Setting
Check

Points

Possible Cause Action
Input Signal P. 77 should be set to 2. Verify that P.77 is set to 2.
Param. Setting P.296 and P.297 may be set for Password Lock. Check with your local equipment supervisor to verify the Password Lock restriction level.