Mitsubishi Electric fr-e700 series, Instruction Manual

Page: 555 / 608

Troubleshooting Check first when you have troubles
FR-E700 SC EC/ENE 7 - 27
7.6.8 Speed varies during operation
When Advanced magnetic flux vector control or the slip compensation is selected, the output fre-
quency varies between 0 and 2Hz as load fluctuates. This is a normal operation and not a fault.
Check Points Possible Cause Countermeasures
Refer to
Page
Input signal Multi-speed command signal is chattering.
Take countermeasures to suppress chatter-
ing.
—
Load Load varies during an operation.
Select Advanced magnetic flux vector con-
trol or General-purpose magnetic flux vector
control.
6-41
Input signal
Frequency setting signal is varying. Check the frequency reference signal. —
The frequency setting signal is affected by
EMI.
Set filter to the analog input terminal using
Pr. 74 "Input filter time constant".
6-182
Take countermeasures against EMI, such as
using shielded wires for input signal lines.
3-52
Malfunction is occurring due to the undesira-
ble current generated when the transistor
output unit is connected. Use terminal PC (terminal SD when source
logic) as a common terminal to prevent a
malfunction caused by undesirable current.
3-27
Parameter
setting
Pr. 80 "Motor capacity" and Pr. 81 "Number of
motor poles" setting is improper for the
capacities of the inverter and the motor for
Advanced magnetic flux vector control or
General-purpose magnetic flux vector con-
trol.
Check the Pr. 80 "Motor capacity" and Pr. 81
"Number of motor poles" setting.
6-41
Fluctuation of power supply voltage is too
large. Change the Pr. 19 "Base frequency voltage"
setting (about 3%) under V/F control.
6-56
Hunting occurs by the generated vibration,
for example, when structural rigidity at load
side is insufficient.
Disable automatic control functions, such as
energy saving operation, fast-response cur-
rent limit function, regeneration avoidance
function, Advanced magnetic flux vector
control, General-purpose magnetic flux vec-
tor control, and stall prevention.
During the PID control, set smaller values to
Pr. 129 "PID proportional band" and Pr. 130
"PID integral time".
Lower the control gain, and adjust to
increase the stability.
—
Change Pr. 72 "PWM frequency selection"
setting.
6-175
Others
Wiring length exceeds 30 m when Advanced
magnetic flux vector control or General-pur-
pose magnetic flux vector control is per-
formed.
Perform offline auto tuning. 6-90
Wiring length is too long for V/F control, and
a voltage drop occurs.
Adjust Pr. 0 Torque boost by increasing with
0.5% increments for low-speed operation.
6-35
Change to Advanced magnetic flux vector
control or General-purpose magnetic flux
vector control.
6-41