L: Protection Functions - YASKAWA A1000 Technical Manual

5.8

L: Protection Functions

 L1: Motor Protection

L1-01: Motor Overload Protection Selection
The drive has an electronic overload protection function that estimates the motor overload level based on output current,
output frequency, thermal motor characteristics, and time. An oL1 fault will be triggered when motor overload is
detected and drive output will be shut off.
L1-01 sets the overload protection function characteristics according to the motor being used.
No.
L1-01
Note: 1. When the motor protection function is enabled (L1-010), an oL1 alarm can be output through one of the multi-function outputs by
setting H2-01 to 1F. The output will close when the motor overload level reaches 90% of the oL1 detection level.
2. Select a method to protect the motor from overheat by setting L1-01 between 1 and 6 when running a single motor from the drive. An
external thermal relay is not needed.
Setting 0: Disabled (motor overload protection is not provided)
This setting should be used if no motor overheat protection is desired or if multiple motors are connected to a single
drive. In this case it is recommended that you install a thermal relay for each motor as shown in
Figure 5.89
NOTICE: Thermal protection cannot be provided when running multi-motors simultaneously with the same drive, or when using
motors with a current rating that is relatively high when compared with other standard motors (such as a submersible motor). Failure to
comply could result in motor damage. Disable the electronic overload protection of the drive (L1-01 = "0: Disabled") and protect each
motor with individual motor thermal overloads.
NOTICE: Close MC1 and MC2 before operating the drive. (MC1 and MC2 cannot be switched off during run.)
Setting 1: General-purpose motor (standard self-cooled)
Because the motor is self-cooled, the overload tolerance drops when the motor speed is lowered. The drive appropriately
adjusts the electrothermal trigger point according to the motor overload characteristics, protecting the motor from
overheat throughout the entire speed range.
Overload Tolerance
Rated Speed = 100% Speed
A: Max. speed for 200LJ and above
B: Max. speed for 160MJ to 180 LJ
C: Max. speed for 132MJ and below
YASKAWA ELECTRIC SIEP C710616 27G YASKAWA AC Drive A1000 Technical Manual
Name
Motor Overload Protection Selection
Power supply
(external fault)
oL1
oL2
SC
Figure 5.89 Example of Protection Circuit Design for Multiple Motors
Motor designed to operate from line power.
Motor cooling is most effective when running at
rated base frequency (check the motor nameplate or
specifications).
Drive
oL1
S3
oL2
N.C.
Thermal
relays
Cooling Ability
5.8 L: Protection Functions
Setting Range Default
0 to 6 Determined by A1-02
Figure 5.89.
motors
M1
M2
Overload Characteristics
Continuous operation at less than line power
frequency with 100% load can trigger motor
overload protection (oL1). A fault is output and the
motor will coast to stop.
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