6
-34
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 120% overload is experienced, set the (hot
start) electronic thermal protection operation time. The factory setting is resistance to 120% 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 6.26 Motor Protection Operation Time
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.
•
For save overload tripping, 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 on the rated current at a low frequency, use a special motor.
Setting the Motor Overload Pre-Alarm
If the motor overload protection function is enabled (i.e., L1-01 is set to 1) and you set H2-01 or H2-02 (multi-
function output terminals M1-M2 and M3-M4 function selection) to 1F (motor overload OL1 pre-alarm), the
L1-01
Set
Value
Motor Type
Tolerance Load Characteristics
Cooling Ability
Electronic Thermal
Operation (at 100%
Motor Load)
1
General-purpose
motor (standard
motor)
Use this motor for
operations using a
commercial power
supply. This motor
construction yields
best cooling effect
when operating at 50/
60 Hz.
When operating continu-
ously at 50/60 Hz or less,
motor overload detection
(OL1) is detected. The
Inverter outputs the error
contact and the motor
coasts to a stop.
T
o
rq
ue (%
)
Short time 60s
Rated rotation speed
= 100% speed
3.7 kW max.
5.5 to 15 kW
18.5 kW min.
80% ED or Frame number Max.
30 min. speed of 200 LJ min.
50% ED or 30 min.
Continuous
Frame
nu m be r
M ax
.
speed of
200 LJ
Frame number Max.
speed of 160 MJ to
180 LJ
Frame number
Max. speed of
132 MJ
min.
Rotation speed (%)
Operating time (min.)
Cold start
Hot start
Motor current (%)
E2-01 is set to 100%
