User`s manual

79
Other Functions Chapter 6-7
6-7 Other Functions
The following description provides information on the other functions and
parameter settings of the Inverter.
6-7-1 Motor Protection Characteristics (n33 and n34)
This parameter setting is for motor overload detection (OL1).
Set Values
• This parameter is used to set the electric thermal characteristics of the
motor to be connected.
• Set the parameter according to the motor.
• If a single Inverter is connected to more than one motor, set the
parameter to 2 for no protection. The parameter is also disabled by setting
n32 for rated motor current to 0.0. To protect each motor from overload,
be sure to take an appropriate measure such as the installation of a
thermal relay.
Set Values • This parameter is used to set the electronic thermal protection constant of
motor overload detection OL1.
• The default setting does not need any changes in normal operation.
• To set the parameter according to the characteristics of the motor, confirm
the thermal time constant with the motor manufacturer and set the
parameter with some margin. In other words, set the value a little shorter
than the thermal time constant.
• To detect motor overloading more quickly, reduce the set value, provided
that it does not cause any application problems.
n33 Motor Protection Characteristic Selection Changes during
operation
No
Setting
range
0 to 2 Unit of
setting
1 Default setting 0
Value Description
0 Protection characteristics for general-purpose induction motors
1 Protection characteristics for Inverter-dedicated motors
2 No protection
n34 Motor Protection Time Changes during
operation
No
Setting
range
1 to 60 (min) Unit of
setting
1 min Default setting 8