YASKAWA CR700

Startup Procedure and Test Run
3
3.11 Problems that Can Frequently Occur during Setup and Possible Solutions
YASKAWA SIEPC71061723A YASKAWA AC Drive CR700 Technical Manual 233
Causes Possible Solutions
The motor flux build up is not enough while using Closed Loop Vector
Control or Advanced Open Loop Vector Control.
• 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 motor flux build up is not enough while using Open Loop Vector
Control.
• 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%].
• Set E1-08 [Mid Point A Voltage] to around 20 V maximum (40 V for 400 V class drive).
Initial motor excitation is not sufficient while using V/f Control. • Set b2-03 = 0.2 to 0.3 [DC Inject Braking Time at Start = 0.2 s to 0.3 s].
• Set 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.
◆ Excessive Output Current at Constant Speed
Causes Possible Solutions
The drive is not appropriate. Confirm if the drive capacity is sufficient.
No-load current and rated slip values are not set appropriately after running
the Auto-Tuning process with Open Loop Vector Control or Closed Loop
Vector Control.
1. Confirm the values in the motor test report.
2. Set E2-03 [Motor No-Load Current] (E4-03 [Motor 2 Rated No-Load Current] for motor 2)
in accordance with test report values.
3. Set E2-02 [Motor Rated Slip] (E4-02 [Motor 2 Rated Slip] for motor 2) to a value of 60% to
80% of the test report value.
◆ Too Much Output Current, Oscillation
Causes Possible Solutions
Gain parameters do not agree with motor parameters while using Open Loop
Vector Control.
• Make sure that motor parameters E2-xx are not too different than the value in the test report.
Do the Auto-Tuning process if it is not done.
• Increase the setting value of n2-01 [Automatic Freq Regulator Gain(F)] in 0.05 increments.
• Increase the setting value of n2-02 [Automatic Freq Regulator Time 1] in 50 ms increments.
Note:
Always set n2-02 ≤ n2-03 [Automatic Freq Regulator Time 2]. Whenever n2-02 is adjusted,
the value set for C4-02 [Torque Compensation Delay Time] must also be increased according
to the same ratio.
• Increase the setting value of C4-02 [Torque Compensation Delay Time] in 10 ms increments.
Note:
Always set C4-02 ≤ C4-06 [Motor 2 Torque Comp Delay Time]. Whenever C4-02 is adjusted,
the value set for n2-02 [Automatic Freq Regulator Time 1] must also be increased according
to the same ratio.
◆ Despite Measures to Increase Flux, Brake Operation Is Slow and Peak Current
at Start Take Too Long
Causes Possible Solutions
S1-04 = 0.00 [Brake Delay Time = 0.00 s]. Set S1-04 ≒ 0.30 to 0.70.
The setting value of S1-07 [Brake Release Torque (FWD)] is too low while
using Open Loop Vector Control, Closed Loop Vector Control, or Advanced
Open Loop Vector Control.
Set S1-07 ≒ 70 to 80.
The V/f setting is too high. Decrease the V/f setting.
◆ Excessive Current Flow When Starting to Hoist Immediately After Stopping
Lowering
Causes Possible Solutions
Depends on motor characteristics. Use the following formula to set S2-03 [Run Cmd Delay Timer (REV/FWD)].
Note:
Refer to the following parameters to get the information required for the necessary
calculations.
• E2-01 [Motor Rated Current (FLA)]
• E2-02 [Motor Rated Slip]
• E2-03 [Motor No-Load Current]