Yaskawa CIMR-V7AM-091 - Manual (Page 8)

Date: 02/20/05, Rev: 05-02 Page 8 of 15 TM.V7SW.091
Multi-function Digital Outputs (Parameters n057 to n059)
When the KEB function is programmed, the Undervoltage detection signal (set value: 15) turns ON
with DC bus voltage less than the KEB Starting Voltage (n048) or during KEB deceleration while the
KEB running signal (set value: 22) turns ON during KEB deceleration or re-acceleration.
The high-speed running signal (set value: 23) is also available. This signal turns ON during speed
agreed of the high (main) speed reference. The high-speed frequency is defined as the reference
when digital input functions Multi-step Speeds 1-3 are OFF (open). The output turns ON/OFF in the
period of 1 second during acceleration or deceleration and in the period of 0.5 second during speed
agreed operation at any frequency reference other than high speed frequency reference, and OFF
during stop.
Mode
High Speed (Main Speed
Frequency Reference Selected)
Low Speed (Any Frequency Reference Other
than Main Speed Frequency Reference)
During Stop OFF OFF
During Acceleration or
Deceleration
ON/OFF in period of 1 second ON/OFF in period of 1 second
During Speed Agreed ON ON/OFF in period of 0.5 second
Stall Prevention Deceleration and Braking Transistor Operational Voltage (n049)
If an Overvoltage trip occurs when KEB starts (no braking resistor and stall prevention during
deceleration enabled: n092 = 0), the stall prevention deceleration operational voltage can be
reduced to avoid an OV trip. When several drives are connected on a common DC bus, connect a
braking resistor to the largest drive and refer to monitor display U-05 (DC bus voltage) to adjust this
parameter in order to avoid OV caused by uneven voltage detection.
・Braking transistor operational voltage: DC bus voltage≧n049
・Braking transistor releasing voltage: DC bus voltage≦n049 -10Vdc (20Vdc for 460V units)
AVR Time Constant (Parameter n139)
The time constant of the output voltage AVR (stabilization) function can be adjusted when the output
current or DC bus voltage oscillates during KEB operation. Adjust this parameter in small steps.
When the set value is 0.00sec, the AVR function is disabled.
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