YASKAWA CR700 Technical Manual

3.11 Problems that Can Frequently Occur during Setup and Possible Solutions
230 YASKAWA SIEPC71061723A YASKAWA AC Drive CR700 Technical Manual
Causes Possible Solutions
The load is too heavy. • Increase the acceleration time.
• Check if the mechanical brake is fully releasing as it should.
• Decrease the load so that the output current remains within the motor rated current.
• Use a larger motor.
Note:
• In extruder and mixer applications, the load will sometimes increase as the temperature
drops.
• Although the drive has a Stall Prevention function and a Torque Compensation Limit
function, accelerating too quickly or trying to drive an excessively large load can exceed the
capabilities of the motor.
The frequency reference is low. • Check E1-04 [Maximum Output Frequency] and increase the setting if it is set too low.
• Check U1-01 [Frequency Reference] for proper frequency reference.
• Check if a frequency reference signal switch has been set to one of the multi-function input
terminals.
• Check for low gain level set to H3-03, H3-11, H3-07 [Terminal A1, A2, A3 Gain Setting].
Incorrect frequency reference setting. If H3-02, H3-10, H3-06 = 1 [MFAI Function Selection = Frequency Reference] has been set,
check whether voltage (current) has been set.
• Check the values set in H3-02, H3-10, and H3-06.
• Check if the analog input values set to terminals A1, A2, and A3 are appropriate using U1-13
to U1-15 [Terminal A1, A2, A3 Level].
Motor characteristics and drive parameter settings are incompatible with one
another.
• Set the correct V/f pattern so that hit matches the characteristics of the motor being used.
• Check the V/f pattern set to E1-03 [V/f Pattern Selection].
• Perform Rotational Auto-Tuning.
Although the drive is operating in vector control mode, Auto-Tuning has not
been performed.
• Perform Auto-Tuning.
• Calculate motor data and reset motor parameters.
• Switch to A1-02 = 0 [Control Method Selection = V/f Control].
The speed estimation response is too slow when A1-02 = 4 [Control Method
Selection = Advanced Open Loop Vector].
Increase the value set in n4-65 [Flux Estimate Response@High Freq] in increments of 0.1.
The Stall Prevention level during acceleration set too low. Increase the value set in L3-02 [Stall Prevent Level during Accel].
Note:
If L3-02 is set too low, acceleration may be taking too long.
The Stall Prevention level during run has been set too low. Increase the value set in L3-06 [Stall Prevent Level during Run].
Note:
If L3-06 is set too low, speed will drop as the drive outputs torque.
Drive reached the limitations of the V/f control. • The motor cable may be long enough (over 50 m) to require Auto-Tuning for line-to-line
resistance.
• Change the V/f pattern to “High Starting Torque”.
• Consider switching to vector control mode.
Note:
Be aware that V/f Control is comparatively limited when it comes to producing torque at low
speeds.
◆ Output Frequency Is Not As High As Frequency Reference
Causes Possible Solutions
Frequency reference is set within the range of the Jump frequency. Adjust d3-01 to d3-03 [Jump Frequency 1 to 3] and d3-04 [Jump Frequency Width].
Note:
Enabling the Jump frequency prevents the drive from outputting the frequencies specified in
the Jump range.
Upper limit for the frequency reference has been exceeded. Set E1-04 [Maximum Output Frequency] and d2-01 [Frequency Reference Upper Limit] to
optimal values.
Note:
Use the following formula to calculate the upper value for the output frequency:
E1-04 × d2-01 / 100
Large load triggered Stall Prevention function during acceleration. • Decrease the load.
• Adjust L3-02 [Stall Prevent Level during Accel].
L3-01 = 3 [Stall Prevention during Accel = Current Limit Method] has been
set.
1. Check whether the V/f pattern and motor parameter settings are appropriate, and set them
correctly.
2. If this does not solve the problem, and it is not necessary to limit the current level of stall
during acceleration, adjust L3-02.
3. If this does not solve the problem, set L3-01 = 1 [Enabled].
The motor is rotating at the following speed:
b2-01 [DC Injection/Zero SpeedThreshold] ≤ Motor Speed < E1-09
[Minimum Output Frequency]
Set the value of E1-09 lower than the value of b2-01.

YASKAWA CR700 Specifications

General

Brand	YASKAWA
Model	CR700
Category	DC Drives
Language	English