Omron SYSDRIVE 3G3RV, User Manual

Page: 265 / 446

Machine Protection
6-
49
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Setting Motor Protection Operation Time
Set
the motor protection operation time in L1-02.
If,
after operating the motor continuously at the rated current, a 150% overload is experienced, set the (hot
start)
electronic thermal protection operation time. The factory setting is resistance to 150% for 60 seconds.
The
following diagram shows an example of the characteristics of the electronic thermal protection operation
time
(L1-02 = 1.0 min., operation at 60 Hz, general-purpose motor characteristics, when L1-01 is set to 1)
Fig 6.39 Motor Protection Operation Time
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Setting Precautions
• If
multiple motors are connected to one Inverter, set parameter L1-01 to 0 (disabled). To protect the motor,
install
a thermal relay in the motor power cable, and perform overload protection on each motor.
• With
applications where the power supply is often turned ON and OFF, there is a risk that the circuit can-
not
be protected even if this parameter has been set to 1 (enabled), because the thermal value will be reset.
• To
detect overloads in good time, set the set value in parameter L1-02 to a low setting.
• When
using a general-purpose motor (standard motor), the cooling ability will be lowered by f 1/4 (fre-
quency).
Consequently, the frequency may cause motor overload protection (OL1) to occur, even below
the
rated current. If operating using the rated current at a low frequency, use a special motor.
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Setting the Motor Overload Pre-Alarm
If
the motor overload protection function is enabled (i.e., L1-01 is set to other than 0) and you set H2-01 to
H2-03
(multi-function output terminals M1-M2, P1-PC, M3-M4, M5-M6, and P2-PC function selection) to 1F
(motor
overload OL1 pre-alarm), the motor overload pre-alarm will be enabled. If the electronic thermal value
reaches
minimum 90% of the overload detection level, the output terminal that has been set will be turned ON.
Operating time (min.)
Cold start
Hot start
Motor current (%)
E2-01 is set to 100%