YASKAWA GA800 Technical Reference page 1013

• Motor loss increases during overexcitation deceleration. Use this function when the duty time factor is 5% ED or
less and the braking time is 90 seconds or less. The load inertia and motor characteristics have an effect on the
braking time. You can use overexcitation deceleration in OLV control and CLV control, but those control methods
decrease the precision of torque control and braking efficiency. Use V/f control for the best results.
• The drive disables these functions during braking with Overexcitation Deceleration 2:
– Hunting Prevention Function (V/f Control)
– Torque Limit Speed Control (OLV Control)
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n3-01: HSB Deceleration Frequency Width
No.
Name
(Hex.)
n3-01 HSB Deceleration
Frequency Width
(0588)
Expert
When you must detect ov [DC Bus Overvoltage] during high-slip braking, set this parameter to a large value.
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n3-02: HSB Current Limit Level
No.
Name
(Hex.)
n3-02 HSB Current Limit Level
(0589)
Expert
Note:
The upper limit of the setting range changes when the setting for C6-01 [Normal / Heavy Duty Selection] changes.
• 150% when C6-01 = 0 [Heavy Duty Rating 1 (HD1) for Constant Torque Applications].
• 110% when C6-01 = 1 [Normal Duty Rating 1 (ND1) for Variable Torque Applications].
When you decrease the setting value for current suppression, it will make the deceleration time longer.
• When you must detect ov [DC Bus Overvoltage] during high-slip braking, set this parameter to a low value.
• If the motor current increases during high-slip braking, decrease the setting value to prevent burn damage in the
motor.
• The overload tolerance for the drive is 150% for Heavy Duty Rating (HD) and 110% for Normal Duty Rating (ND).
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n3-03: HSB Dwell Time at Stop
No.
Name
(Hex.)
n3-03 HSB Dwell Time at Stop
(058A)
Expert
If there is too much inertia or when the motor is coasting to a stop after high-slip braking is complete, increase the
setting value. If the setting value is too low, machine inertia can cause the motor to rotate after high-slip braking is
complete.
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n3-04: HSB Overload Time
No.
Name
(Hex.)
n3-04 HSB Overload Time
(058B)
Expert
If a force on the load side is rotating the motor or if there is too much load inertia connected to the motor, the drive
will detect oL7.
YASKAWA SIEPC71061737D GA800 Drive Technical Reference
V/f CL-V/f OLV CLV AOLV
Sets the amount by which the output frequency is to be lowered during high-slip braking, as a
percentage of E1-04 [Maximum Output Frequency], which represents the 100% value.
V/f CL-V/f OLV CLV AOLV
Sets the maximum current output during high-slip braking as a percentage, where E2-01 [Motor
Rated Current (FLA)] is 100%. Also set the current suppression to prevent exceeding drive overload
tolerance.
V/f CL-V/f OLV CLV AOLV
Sets the dwell time, a length of time when high-slip braking is ending and during which the motor
speed decreases and runs at a stable speed. For a set length of time, the drive will hold the actual
output frequency at the minimum output frequency set in E1-09.
V/f CL-V/f OLV CLV AOLV
Sets the time used to detect oL7 [High Slip Braking Overload], which occurs when the output
frequency does not change during high-slip braking. Usually it is not necessary to change this
parameter.
12.10 n: Special Adjustment
Description
OLV/PM AOLV/PM CLV/PM EZOLV OLV/PM
Description
OLV/PM AOLV/PM CLV/PM EZOLV OLV/PM
Description
OLV/PM AOLV/PM CLV/PM EZOLV OLV/PM
Description
OLV/PM AOLV/PM CLV/PM EZOLV OLV/PM
Default
(Range)
5%
(1 - 20%)
Default
(Range)
Determined by C6-01 and
L8-38
(0 - 150%)
Default
(Range)
1.0 s
(0.0 - 10.0 s)
Default
(Range)
40 s
(30 - 1200 s)
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