YASKAWA CR700

3.11 Problems that Can Frequently Occur during Setup and Possible Solutions
232 YASKAWA SIEPC71061723A YASKAWA AC Drive CR700 Technical Manual
◆ Load Slips at Start
Causes Possible Solutions
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 low.
Increase the setting values of S1-05 to S1-08.
The V/f setting is too low. Increase the V/f setting.
The setting value of C4-02 [Torque Compensation Delay Time] is too high
while using Open Loop Vector Control.
Set C4-02 ≒ 20 [20 ms].
The setting value of S1-09 [Torque Compensation (FWD)] (the amount of
torque forcing) is too low while using Open Loop Vector Control, Closed
Loop Vector Control, or Advanced Open Loop Vector Control.
Set S1-09 ≒ 50 to 80 [50% to 80%].
The output current is more than 125% of the rated current while using
Closed Loop Vector Control or Advanced Open Loop Vector Control.
Do these procedures to solve problems with starting up magnetic flux.
• Set b2-03 = 0.2 to 0.3 [DC Inject Braking Time at Start = 0.2 s to 0.3 s].
• Set d6-03 = 1 [Field Forcing Selection = Enabled] and d6-06 = 200 to 400 [Field Forcing
Limit = 200% to 400%].
• Do the initial excitation process.
The output current is more than 125% of the rated current while using Open
Loop Vector Control.
Do these procedures to solve problems with starting up magnetic flux.
• Set b2-03 = 0.2 to 0.3 [DC Inject Braking Time at Start = 0.2 s to 0.3 s].
• Set b2-08 = 100 to 200 [Magnetic Flux Compensation Value = 100% to 200%].
• Increase the setting value of E1-08 [Mid Point A Voltage] to around 20 V maximum (40 V for
400 V class drive).
The output current is more than 125% of the rated current while using V/f
Control.
Do these procedures to solve problems with starting up magnetic flux.
• Set b2-03 = 0.2 to 0.3 [DC Inject Braking Time at Start = 0.2 s to 0.3 s].
• Increase the setting value of E1-08 [Mid Point A Voltage] to around 20 V maximum (40 V for
400 V class drive).
Note:
Refer to “Magnetic Flux Compensation (Start-up Current Suppression)” on page
236 to solve problems in flux build up.
◆ Load Slips at Stop
Causes Possible Solutions
The setting value of S1-05 [Brake Release Current (FWD)] is too low while
using V/f control or OLV control.
Increase the setting value of S1-15.
The setting value of b2-04 [DC Inject Braking Time at Stop] is too low while
using Closed Loop Vector Control or Advanced Open Loop Vector Control.
Set b2-04 > 0.50.
Brake hold settings are not correct. Increase the setting values of S1-12 [Brake Hold Frequency (FWD)] and S1-13 [Brake Hold
Frequency (REV)].
◆ Slipping Occurs During Extremely Fast Inching
Causes Possible Solutions
Drive operation and brake operation do not keep up with the inching
operation.
Increase the setting value of S2-01 [Run Cmd Minimum On Time (FWD)] and S2-02 [Run Cmd
Minimum On Time (REV)].
◆ Load Falls When Brake Is Applied
Causes Possible Solutions
The open/close timing of the brake is incorrect. • Increase the value set in S1-14 [Slip Prevention Frequency].
• Increase the time set in S1-15 [Slip Prevention Time].
The DC injection braking is insufficient. Increase the value set in b2-02 [DC Injection Braking Current].
◆ Excessive Current Occurs at Start
Causes Possible Solutions
The brake sequence is not adjusted. • Decrease the setting values of S1-01 and S1-02 [Brake Release Frequency].
• Decrease the setting value of S1-03 [Brake Delay Frequency].
• Set S1-04 [Brake Delay Time] to align with the machine.
The motor flux build up is not enough while using Closed Loop Vector
Control or Advanced Open Loop Vector Control.
• Set d6-03 = 1 [Field Forcing Selection = Enabled] and d6-06 ≒ 200 to 400 [Field Forcing
Limit ≒ 200% to 400%].
• Do the initial excitation process.
Torque settings are too low while using Open Loop Vector Control, Closed
Loop Vector Control, or Advanced Open Loop Vector Control.
• Set L7-01 to L7-04 ≒ 150 [Torque Limit ≒ 150%].
• Set S1-07 ≒ 70 to 80 [Brake Release Torque (FWD) ≒ 70% to 80%].