L: Protection Functions; L1: Motor Protection - YASKAWA CIPR-GA50C series Technical Manual

12.9

L: Protection Functions

L parameters set the following functions.
• Motor Overload Protection
• Operation During Momentary Power Loss
• Stall Prevention
• Speed Detection
• Auto Restart
• Detection of Overtorque/Undertorque
• Torque Limit
• Hardware Protection
◆

L1: Motor Protection

L1 parameters set the motor overload protection function.
■
Motor Protection Using Positive Temperature Coefficient (PTC) Thermistors
The temperature resistance characteristics of three PTC thermistors in the motor stator winding protect the motor
from overheat.
A PLC thermistor must have the characteristics shown in
If the PTC input signal input to the drive is more than the overload alarm level, the drive detects oH3 [Motor
Overheat (PTC Input)]. The drive continues the operation set in L1-03 [Motor Thermistor oH Alarm Select]. By
default, the keypad shows oH3 and the drive continues operation.
The overheat fault level triggers an oH4 [Motor Overheat Fault (PTC Input)] fault, and outputs a fault signal. The
drive outputs a fault signal and uses the stop method set in L1-04 [Motor Thermistor oH Fault Select] to stop the
motor.
Note:
PTC is an acronym for Positive Temperature Coefficient.
■
L1-01: Motor Overload (oL1) Protection
No.
Name
(Hex.)
L1-01 Motor Overload (oL1)
Protection
(0480)
This parameter enables and disables the motor overload protection with electronic thermal protectors.
The cooling capability of the motor changes when the speed control range of the motor changes. Use an electronic
thermal protector that aligns with the permitted load characteristics of the motor to select motor protection.
The electronic thermal protector of the drive uses these items to calculate motor overload tolerance and supply
overload protection for the motor:
• Output Current
• Output Frequency
YASKAWA SIEPC71061753A GA500 Technical Manual
Figure 12.106 PTC Thermistor Temperature and Resistance
V/f OLV OLV/PM AOLV/PM EZOLV OLV/PM
Sets the motor overload protection with electronic thermal protectors.
Figure 12.106 for each motor phase.
Description

12.9 L: Protection Functions

Default
(Range)
Determined by A1-02
(0 - 6)
12
665