System Component Compatibility; Motor Protection Device Correction Factors - YASKAWA V1000 Series Installation & Start-Up Manual

resulting in additional motor heating. Unintentional triggering of the overload device may
also occur. Therefore, do not use high starting torque V/f patterns or use excessive voltage
boost settings unless absolutely necessary.
Correcting Nuisance Tripping Resulting from High AC Drive Carrier Frequency
Thermal overload element heating is influenced by carrier frequency and lead length.
Current waveforms generated by PWM drives tend to create additional temperature rise in
overload relays. Therefore, it may be necessary to increase the trip level setting by the
factors listed in Table 7.3
actual overload condition is not present prior to increasing the trigger level.
WARNING! Risk of Fire. Confirm an actual motor overload condition is not present prior to increasing the
thermal OL trip setting. Check local electrical codes before making adjustments to motor thermal overload
settings.
Example:A thermal OL relay with an adjustment range of 1.1 to 1.6 A is used with a drive
working with 8 kHz carrier frequency. The motor rated current is 1.2 A. The overload trip
level may be corrected to: 1.2 A x 1.21 = 1.45 A
Table 7.3 shows recommended correction factors for the motor protection device trigger
level based on adjustment range and carrier frequency of the drive.
Table 7.3 Motor Protection Device Correction Factors
Adjustment Range/ Rated
Current
3.2 to 50 A
0.5 to 2.5 A
0.32 to 0.4 A
0.16 to 0.25 A

System Component Compatibility

Thoroughly review the application requirements to ensure compatibility of the selected
components (motor, speed range, application speed-torque requirements).
YASKAWA ELECTRIC TOEP C710606 09B YASKAWA AC Drive V1000 Installation & Start-Up Manual
when encountering nuisance triggering of the relay. Confirm an
Drive Carrier Frequency Setting (KHz)
2 4 6
1.07 1.12 1.16
1.08 1.13 1.17
1.09 1.15 1.21
1.10 1.17 1.24
7.4 Installing Peripheral Devices
8 10 12
1.18 1.19 1.21
1.21 1.24 1.26
1.25 1.29 1.33
1.28 1.33 1.38
14 16
1.22 1.23
1.28 1.29
1.35 1.37
1.42 1.46
283
7