Thermal
relay
motor
Power supply
M1
oL1
oL2
M2
Drive
(external fault)
N.O. input
oL1
oL2
SC
S3
Figure i.55 Example of Protection Circuit Design for Multiple Motors
NOTICE: Thermal protection cannot be provided when running multi-motors simultaneously with the same drive, or when using motors with
a relatively high current rating compared to 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.
Setting 1: General-Purpose Motor (Standard Self-Cooled)
Because the motor is self-cooled, the maximum load current 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.
Maximum Load Current
Cooling Ability
Overload Characteristics
A: Max. speed for 200LJ and above
B: Max. speed for 160MJ to 180 LJ
C: Max. speed for 132MJ and below
05 33 100 120 167 200
Speed (%)
Continuous
A
B
C
Rated Speed=100% Speed
60 s
150
100
90
60
50
Torque (%)
Motor designed to operate from line
power.
Motor cooling is most effective when
running at rated base frequency (check
the motor nameplate or 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 4: PM Derated Torque Motor
Use this setting when operating a PM motor. PM motors for derated torque have a self-cooling design and the maximum load
current drops as the motor slows. Electronic thermal overload is triggered in accordance with the motor overload characteristics,
providing overheat protection across the entire speed range.
Maximum Load Current
Cooling Ability
Overload Characteristics
Continuous
60 s
Motor Speed (%)
Torque (%)
150
10
33
100
120
100
80
50
0.0
Motor is designed to produce 100%
torque at base speed. Built with
effective cooling capabilities.
Reaching 100% when operating at
below the base frequency causes a
motor overload fault (oL1). The drive
fault output closes and the motor coasts
to stop.
n
L1-02: Motor Overload Protection Time
Sets the detection time of motor overheat due to overload. This setting rarely requires adjustment, but should correlate with
the motor maximum load current protection time for performing a hot start.
No.
Name
Setting Range
Default
L1-02
Motor Overload Protection Time
0.1 to 50.0 minutes
1.0 minute
Defaulted to operate with an allowance of 150% overload operation for one minute in a hot start.
Figure i.56
illustrates an example of the electrothermal protection operation time using a general-purpose motor operating at
the value of E1-06, Motor Base Speed, with L1-02 set to one minute.
i.5 Start-Up Programming and Operation
58
YASKAWA ELECTRIC TOEP C710616 54A YASKAWA AC Drive - Z1000 Quick Start Guide
Summary of Contents for Z1000 CIMR-ZU*A Series
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