YASKAWA CR700

3.11 Problems that Can Frequently Occur during Setup and Possible Solutions
234 YASKAWA SIEPC71061723A YASKAWA AC Drive CR700 Technical Manual
◆ Brake Slips at Start
Causes Possible Solutions
S1-04 = 0.00 [Brake Delay Time = 0.00 s]. Set S1-04 ≒ 0.30 to 0.70.
The setting values of S1-05 [Brake Release Current (FWD)], S1-06 [Brake
Release Current (REV)], S1-07 [Brake Release Torque (FWD)], and S1-08
[Brake Release Torque (REV)] are too high.
Decrease the setting values of S1-05 to S1-08. Set S1-07 ≒ 70 to 80.
The V/f setting is too high. Decrease the V/f setting.
◆ Brake Grinding Occurs at Stop
Causes Possible Solutions
The setting values of S1-12 and S1-13 [Brake Hold Frequency] are too high. Decrease the setting values of S1-12 and S1-13.
The setting value of S1-14 [Slip Prevention Frequency] is too high. Decrease the setting value of S1-14.
The setting value of S1-15 [Slip Prevention Time] is too high. Decrease the setting value of S1-15.
The setting value of b2-04 [DC Inject Braking Time at Stop] is too high. Set b2-04 < 0.5 [DC Inject Braking Time at Stop < 0.50 s].
◆ Impact Stop Is Not Available After the Motor Stops
Causes Possible Solutions
The setting values of S3-03 [Impact Stop Detect Torque (FWD)] and S3-04
[Impact Stop Detect Torque (REV)] are too low.
Increase the setting value of S3-03 and S3-04.
The value set in S3-05 [Impact Stop Detection Time] is too low. Increase the setting value of S3-05.
◆ Motor Keeps Rotating at the Creep Frequency During Impact Stop Operation
Causes Possible Solutions
The setting values of S3-03 [Impact Stop Detect Torque (FWD)] and S3-04
[Impact Stop Detect Torque (REV)] are too high.
Decrease the setting value of S3-03 and S3-04.
Torque does not increase when the transport cart impacts something. Check the slip of the cart wheels, and if something causing mechanical friction.
The value set in S3-02 [Impact Stop Creep Time] is too high. Decrease the setting value of S3-02.
◆ Accelerates Despite a Heavy Load When Using the Light-Load Acceleration 1
Function
Causes Possible Solutions
The settings in S4-04 [Light-load 1 Detect Torque (FWD)] and S4-05 [Light-
load 1 Detect Torque (REV)] are too high.
Decrease the setting value of S4-04 and S4-05.
The value set in S4-07 [Light-load 1 Detect Time] is too low. Increase the setting value of S4-07.
◆ No Acceleration Despite a Light Load When Using the Light-Load Acceleration
1 Function
Causes Possible Solutions
Light-load Acceleration 1 is not enabled. Enable Light-load Acceleration 1 by one of the following ways.
• Set H1-xx = 30 [MFDI Function Selection = Light-load Acceleration 1 Enabled], and have
that terminal switch ON.
• Set S4-01 = 1 [Light-load Accel Ctrl Selection = Light-load Accel Ctrl 1 enabled].
The settings in S4-04 [Light-load 1 Detect Torque (FWD)] and S4-05 [Light-
load 1 Detect Torque (REV)] are too low.
Increase the setting value of S4-04 and S4-05.
The mechanical loss for the crane is greater than the value set in S4-05 while
operating in reverse.
The following procedure explains how to adjust S4-20 [Light-load 1 Torque Bias (REV)].
1. Operate the drive with no load at the frequency set in S4-06 [Light-load 1 Detect
Frequency], and monitor the value displayed in U1-09 [Torque Reference].
2. Set the reverse value of U1-09 to S4-20.
Note:
Refer to “Light-load Acceleration 1 Function” on page
207 for more information about Light-load Acceleration 1.