Mitsubishi Electric Mitsubishi A500 Inverter

The inverter output is stopped if a contact fault occurs at the connector between the inverter and a communication option, or if the communication option itself develops a fault. The numbers '1' to '3' indicate the specific option slot numbers where the fault is detected.

This function stops the inverter output if a fault occurs in the brake circuit, often due to damaged brake transistors. When this fault occurs, the inverter power must be switched off immediately to prevent further damage.

The inverter self-determines an alarm and stops its output if the arithmetic operation of the built-in CPU does not complete within a predetermined period. This indicates an internal processing fault within the inverter's core control unit.

The inverter output is stopped if the encoder signal is lost (turned off) during orientation, PLG feedback, or vector control operations when using the FR-A5AP. This indicates a disruption in the feedback signal from the encoder.

The inverter output is stopped if the cooling fin overheats, causing the internal overheat sensor to actuate. This indicates that the inverter's thermal management system has detected excessive heat.

This function stops the inverter output if a ground fault overcurrent flows. This is typically caused by a ground fault occurring in the inverter's output side, such as in the motor winding or the connecting cables.

This fault activates when an input power failure or shut-off lasts longer than 15ms, stopping the inverter output to prevent control circuit malfunction. During this event, the alarm warning output contacts open across terminals B-C and close across terminals A-C. If the power failure exceeds 100ms, the alarm warning output is not provided, and the inverter may auto-restart if the start signal is active upon power restoration.

This function stops the inverter output if one of the three phases (U, V, W) on the inverter's output side (load side) experiences an open phase. It can also be triggered if the rated motor current is significantly lower than the rated inverter current.

This error occurs if a start signal is entered when only the control circuit power (connected to R1, S1 <L11, L21> terminals) is supplied to the inverter, and the main circuit power (R, S, T <L1, L2, L3> terminals) is not connected. This improper power sequencing can potentially damage the inverter.

The inverter output is stopped if an external thermal relay (used for motor overheat protection) or an internally mounted motor temperature relay switches on (contacts open). If the relay contacts reset automatically, the inverter requires a manual reset before it can restart. This protection is only active when '7 (OH signal)' is set in Pr. 180 to Pr. 186.

The inverter output is stopped because the running frequency has fallen to 0 due to the activation of stall prevention. This typically indicates that the motor is operating under a severe overload condition, causing the inverter to reduce frequency to zero to prevent damage.

The inverter output is stopped if a functional alarm occurs in the plug-in option loaded in the corresponding slot (1, 2, or 3). This can include a communication alarm for a communication option or a contact fault for other types of plug-in options.

The inverter output is stopped if two or more communication options are fitted simultaneously (with specific exceptions like FR-A5NR). If a high power factor converter is connected, this alarm also triggers if an AC power supply is accidentally connected to the R, S, T (<L1, L2, L3>) terminals.

The inverter output is stopped if a fault occurs in the E²PROM device, which is responsible for storing parameter settings. This indicates an issue with the inverter's non-volatile memory.

This function stops the inverter output if communication between the inverter and the Parameter Unit (PU) is suspended. This can occur if the operation panel or PU is disconnected when Pr. 75 is set to '2', '3', '16', or '17'. It also triggers if successive communication errors exceed the permissible retries when Pr. 121 is '9999' or if communication is broken for the time set in Pr. 122.

The inverter output is stopped because operation could not be resumed properly within the configured number of retries. This alarm indicates that a preceding error repeatedly occurred, exhausting the allowed retry attempts.

This fault indicates motor overheating caused by overload or insufficient cooling during constant-speed operation. A pre-alarm (TH) is triggered at 85% of the preset value, followed by a full shut-off when the specified threshold is reached, protecting the motor. This protection may not be sufficient for special motors (e.g., multi-pole) or multiple motors, requiring an external thermal relay.

This fault occurs when the inverter output current exceeds 150% of its rated current (but less than 200%), triggering the electronic overcurrent protection with inverse-time characteristics. The inverter stops its output to protect its internal output transistors. The inverter has an overload immunity of 150% for 60 seconds.

This function stops the inverter output if the power supply voltage drops below 150V (for 200V class inverters) or approximately 300V (for 400V class inverters). This prevents improper control circuit operation, reduced motor torque, or increased heat generation. It also activates if a jumper or DC reactor is not connected across terminals P/+-P1.

This indication appears on the operation panel when the inverter's cooling fan stops due to a fault or operates incorrectly relative to the setting of Pr. 244 ('cooling fan operation selection'). This applies to inverters equipped with a cooling fan.

This is a warning indicating that the stall prevention function has been activated due to motor current exceeding 150% (or the value set in Pr. 22) of the rated inverter current. During acceleration, deceleration, or constant-speed operation, the frequency is adjusted to prevent an overcurrent shut-off. The inverter output is *not* shut off.