5.7 L: Protection Functions
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L1: Motor Protection Functions
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L1-01: Motor Overload Protection Function 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.
L1-01 sets the overload protection function characteristics according to the motor being used.
No.
Name
Setting Range
Default
L1-01
Motor Overload Protection Selection
0 to 2
1
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 one drive. In
this case it is recommended that you install a thermal relay for each motor as show in
Figure 5.33
Drive
Power
supply
M1
MC1
MC1, MC2: Magnetic contactors
L10, L20: Thermal relays
L10
MC2
L20
M2
Figure 5.33 Example of Protection Circuit Design for Multiple Motors
NOTICE: Protect each motor with individual thermal overloads when multiple motors are connected to one drive. 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.
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
Overload Characteristics
Cooling Ability
Motor designed to operate from line
power.
Motor cooling is most effective when
running at rated nameplate base
frequency (check the motor
specifications).
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.
Setting 2: Drive Dedicated Motor (constant torque, 1:10)
Use this setting when operating a drive duty motor with a torque ratio of 1:10. This motor type is allowed to run with 100%
load from 10% up to 100% speed. Running slower speeds with full load can trigger an overload fault.
5.7 L: Protection Functions
102
SIEP C710606 33A OYMC AC Drive – J1000 User Manual
