Mitsubishi Electric FR-D720S SC EC, Инструкция по эксплуатации

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Selection and protection of a motor Parameter
6 - 66
6.7 Selection and protection of a motor
6.7.1 Motor overheat protection (Electronic thermal O/L relay)
(Pr. 9, Pr. 51, Pr. 561)
The FR-D700 SC EC frequency inverters have an internal electronic motor protection function
that monitors the motor frequency and motor current. Overload conditions are identified and the
motor protection function is triggered on the basis of these two factors, in combination with the
rated motor current. The electronic motor protection function is primarily for protection against
overheating at intermediate speeds and high motor torques. The reduced cooling performance
of the motor fan under these conditions is also taken into account.
The above parameters can be set when Pr. 160 = 0.
When parameter is read using the FR-PU04, a parameter name different from an actual
parameter is displayed.
Purpose Parameters that must be set
Refer to
Section
Motor protection from overheat Electronic thermal O/L relay/
PTC thermistor protection Pr. 9, Pr. 51,
Pr. 561 6.7.1
Constant torque motor Applied motor Pr. 71
The motor performance can be
maximized for operation in magnetic
flux vector control method. Offline auto tuning Pr. 71, Pr. 80,
Pr. 82–Pr. 84,
Pr. 90, Pr. 96 6.7.3
Pr.
No.
Name
Initial
Value
Setting Range Description Parameters referred to
Refer to
Section
9
Electronic thermal O/L
relay
Rated
inverter
output
current
0–500A Set the rated motor current.
71
72
79
128
178–182
190/
192/197
Applied motor
PWM frequency
selection
Operation mode
selection
PID action
selection
Input terminal
function selection
Output terminal
function selection 6.7.2
6.14.1
6.17.1
6.19.1
6.9.1
6.9.5
51
Second electronic
thermal O/L relay
9999
0–500A
Made valid when the RT signal is
on.
Set the rated motor current.
9999
Second electronic thermal O/L
relay invalid
561
PTC thermistor protec-
tion level
9999
0.5–30k
Ω
Set the level (resistance value)
for PTC thermistor protection
activates.
9999
PTC thermistor protection is
inactive.