Protective And Diagnostics Functions - Mitsubishi Electric FR-A800 Series Beginner's Manual

Protective and diagnostics functions

7 Protective and diagnostics functions
The Mitsubishi Electric inverters of the FR-A800 series have many functions that protect both the in-
verter itself and the connected motor against damage when errors occur. If a serious error triggers a
protective function the inverter output is turned off, the motor coasts to a stop and an error code is
displayed on the parameter unit. It is then usually easy to localise the cause of the problem with the
help of the error code and the troubleshooting information in the inverter documentation. Further as-
sistance is always available from Mitsubishi Electric service if necessary.
Please note the following important points for dealing with error codes:
● Power is needed to store error codes
Error codes can only be output after an error occurs if the inverter's power supply remains on.For
example, if the power is switched on by a contact or that trips when a protective function activates
the error codes cannot be stored and will be lost.
● Error code display
When a protective function activates, the appropriate error code is automatically displayed on
the parameter unit.
● Resetting after activation of protective functions
When a protective function activates, the inverter's power output is disabled, cutting off the
power to the connected motor, which then coasts to a halt. The inverter cannot be restarted until
the protective functions have been reset with a RESET command.
When an error occurs you should always first localise and correct the cause. Only reset the inverter
and continue normal operation when you are sure that the problem has been resolved.
The error codes that can be displayed can be divided into four basic categories:
– Error messages
Error messages are normally caused by operator or configuration errors. These codes do not
disable the inverter's power output.
– Warnings
Warnings also do not disable inverter's power output – here too, the motor continues to run.
However, if you ignore a warning and fail to correct the cause it can lead to a fault.
– Alarms
Alarms do not disable the inverter output.
– Faults
Faults are errors that activate the inverter's protective functions, which include disabling the
power output and switching off the connected motor.
Frequency Inverters - Beginner's Guide 7 - 1