Mitsumi electronic FR-F520-0.75K, 55K instruction manual Instantaneous power failure is within 15ms

Operation Panel

Indication

Name

Operation Panel

Indication

Name

Description

Check point

Corrective action

Operation Panel

Indication

Name

Description

Check point

Corrective action

PROTECTIVE FUNCTIONS

E.THM

FR-PU04

Motor Overload

Motor overload shut-off (electronic overcurrent protection) (Note 1)

The electronic overcurrent protection in the inverter detects motor overheat due to overload or reduced cooling capability during constant-speed operation. When 85% of the preset value is reached, pre-alarm (TH indication) occurs. When the specified value is reached, the protective circuit is activated to stop the inverter output. When a special motor such as a multi-pole motor or two or more motors are run, provide a thermal relay in the inverter output side since the motor(s) cannot be protected by the electronic overcurrent protection.

Check the motor for use under overload.

•Reduce the load weight.

•For a constant-torque motor, change the Pr. 71 setting to the constant-torque motor setting.

E.THT

FR-PU04

Inv. Overload

Inverter overload shut-off (electronic overcurrent protection) (Note 1)

If a current of more than 120% of the rated output current flows and overcurrent shut-off does not occur (150% or less), inverse-time characteristics cause the electronic overcurrent protection to be activated to stop the inverter output in order to protect the output transistors.

(Overload immunity 120%, 60s.)

Check the motor for use under overload.

Reduce the load weight.

Note 1: Resetting the inverter initializes the internal heat integrating data of the electronic overcurrent protection.

E.IPF

FR-PU04

Inst. Pwr. Loss

	Instantaneous power failure protection
	If a power failure occurs for longer than 15ms (this also applies to inverter input
	shut-off), the instantaneous power failure protective function is activated to stop
	the inverter output in order to prevent the control circuit from malfunctioning. At
Description	this time, the alarm warning output contacts open (across terminals B-C) and
	close (across terminals A-C). (Note 2) If a power failure persists for longer than
	100ms, the alarm warning output is not provided, and the inverter restarts if the
	start signal is on upon power restoration. (The inverter continues operating if an
	instantaneous power failure is within 15ms.)
Check point	Find the cause of instantaneous power failure occurrence.
	•	Remedy the instantaneous power failure.
Corrective action	•	Prepare a backup power supply for instantaneous power failure.
	•	Set the function of automatic restart after instantaneous power failure. (Refer
		to page 89.)

Note 2: When an instantaneous power failure occurs, the alarm display and alarm output are not provided, but the inverter performs protective operation to prevent a fault from occurring in itself. In some operating status (load size, acceleration/deceleration time setting, etc.), overcurrent or other protection may be activated upon power restoration.

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