User Manual V 1-4.XX User guide

9-8 Applications
To enable the 400% motor current function, set Max Mtr Current
(parameter 195) to a value of 1.
Important: When you enable the 400% motor current function, you
should be aware that torque regulation specifications only apply to the
0 – 100% torque range.
When the drive is configured for 400% motor current, the current
loops are rescaled to allow a larger range of motor current at the
expense of decreased current resolution. Only use the increased
current range for large drive to motor ratios. In cases where there is
not a large difference between the drive rated current and the motor
rated current, little added benefit is provided for most applications.
The increased current range results in decreased current resolution
and therefore a decreased signal to noise ratio for the current
feedback. All other drive operations remain the same.
The duty cycle for operation above 100% load (for example, 400%
motor current) must be limited to thermally protect the motor. Check
with the motor vendor for duty cycle guidelines. You may want to
consider using external motor thermal protection.
Important: The maximum current limits that you specify in Pos Mtr
Cur Lim and Neg Mtr Cur Lim set the maximum/ minimum values for
Pos Torque Lim (parameter 74) and Neg Torque Lim (parameter 75). If
you lower the values of Pos Mtr Cur Lim and Neg Mtr Cur Lim, you
will clamp the values of Pos Torque Lim and Neg Torque Lim. If you
later raise the value of Pos Mtr Cur Lim and Neg Mtr Cur Lim, the
values of Pos Torque Lim and Neg Torque Lim remain at the lower
value.
Understanding the Scale and
Offset Parameters for Analog
I/O
The following section provides information to help you understand
and use the scale and offset parameters for analog I/O. This is an
alternate method for determining values for your scale and offset
parameters.
Understanding the Scale and Offset Parameters for Input
In example 1, a potentiometer with a range of ±10V DC has been
connected at analog input 2. An In 2 Value (parameter 99) has been
linked to Speed Ref 7 (parameter 36) in the drive, which gives the
potentiometer control of speed reference 7.
file:
Application
group:
400% Mtr Current
When: The maximum current is:
Max Mtr Current (parameter 195) is 1 400% motor current.
Max Mtr Current is 0 200% motor current.
The drive current limit is less than the
motor current limit
Determined by the drive current limit.
file:
Interface/Comm
group:
Analog Inputs