Delta VFD-EL-W Series, User Manual

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Chapter 4 Parameters

VFD-EL-W
4-61
Group 6: Protection Parameters

You can set this parameter during operation.
06.00 Over-Voltage Stall Prevention Unit: 0.1
Settings 230V series 330.0 – 410.0V Default: 390.0
460V series 660.0 – 820.0V Default: 780.0

The default for 230V series is 390.0; the default for 460V series is 780.0.

0.0: Disables the Over-voltage Stall Prevention (with brake unit or brake resistor)

During deceleration, the DC bus voltage may exceed its Maximum Allowable Value due to motor regeneration.
When this function is enabled, the AC motor drive does not decelerate further and keep the output frequency
constant until the voltage drops below the preset value again.

This parameter is suitable for uncertain load inertia. In normal inertia load condition, over-voltage stall
prevention does not occur and the actual deceleration time is the deceleration time setting. However, when the
load inertia is large, the AC motor drive automatically increases the deceleration time until it stops. You can
also install a brake resistor to absorb the excessive regenerative voltage. If the deceleration time affects your
application, it is not recommended to use this function.
high voltage at DC side
over-voltage
detection level
output
frequency
time
Deceleration characteristic
when Over-Voltage Stall
Prevention enabled
Frequency Held
time
previous deceleration time
actual time to decelerate to stop when over-voltage
stall prevention is enabled
06.01

Over-Current Stall Prevention during Acceleration
Unit: 1
Settings 20–250% Default: 170
0: Disable

A setting of 100% is equal to the AC motor drive’s Rated Output Current.

During acceleration, the AC motor drive output current may increase abruptly and exceed the value specified
in Pr.06.01 due to rapid acceleration or excessive load on the motor. When this function is enabled, the AC
motor drive stops accelerating and keeps the output frequency constant until the current drops below this
setting.