11.9 L: Protection Function
746 YASKAWA SIEPC71061723A YASKAWA AC Drive CR700 Technical Manual
3. Set these MFAI terminals:
• Set H3-05 = 0 [Terminal A3 Signal Level Select = 0 to 10V (Lower Limit at 0)].
• Set H3-06 = E [Terminal A3 Function Selection = Motor Temperature (PTC Input)].
4. Set these L1 parameters.
• L1-03 [Motor Thermistor oH Alarm Select]
• L1-04 [Motor Thermistor oH Fault Select]
• L1-05 [Motor Thermistor Filter Time]
■ L1-01: Motor Overload (oL1) Protection
No.
(Hex.)
Name Description
Default
(Range)
L1-01
(0480)
Motor Overload (oL1)
Protection
Sets the motor overload protection with electronic thermal protectors.
Determined by A1-02
(0 - 3, 6)
Parameter L1-01 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 Output current, Output frequency, Motor thermal characteristics,
and Time characteristics to calculate motor overload tolerance and supply overload protection for the motor. If the
drive detects motor overload, the drive will trigger an oL1 [Motor Overload] and stop the drive output.
You can set a motor overload alarm. Set H2-02 = 1F [Term M3-M4 Function Selection = Motor Overload Alarm
(oL1)] to enable this function. If the motor overload level is more than 90% of the oL1 detection level, the output
terminal activates and triggers an overload alarm.
Note:
When you connect only one motor to a drive, set L1-01 = 1 to 3 or 6 [Enabled]. External thermal relays are not necessary in these
conditions.
0 : Disable
Disable motor protection when motor overload protection is not necessary or when the drive is operating more
than one motor.
Refer to the figure for an example of the circuit configuration to connect more than one motor to one drive.
Figure 11.87 Protection Circuit Configuration to Connect More than One Motor to One Drive
NOTICE: When you connect more than one motor to one drive or when the motor amp rating is higher than the drive amp
rating, set L1-01 =0 [Motor Overload (oL1) Protection = Disabled] and install thermal overload relays for each motor. The
electronic thermal protection of the drive will not function and it can cause damage to the motor.
1 : Variable Torque
Use this setting for general-purpose motors with a 60 Hz base frequency.
The overload tolerance decreases as Run decreases because the cooling fan speed decreases and the ability of the
motor to cool decreases in the low speed range. The overload tolerance characteristics of the motor change the
trigger point for the electronic thermal protector. This provides motor overheat protection from low speed to high
speed across the full speed range.
To Next Page
Loading...
