Mitsubishi Electronics FR-A500L instruction manual Oht

			PROTECTIVE FUNCTIONS
Operatio	Paramete
n Panel
	r Unit	Name	Description
Display
	(FR-PU04)
(FR-DU04)
			This function stops the inverter output if a ground fault occurs in the
E. GF	Ground	Output side ground fault	inverter's output (load) side and a ground fault current flows. A ground
	Fault	overcurrent protection	fault occurring at low ground resistance may activate the overcurrent
			protection (OC1 to OC3).
			If the external thermal relay designed for motor overheat protection or
		External thermal relay	the internally mounted temperature relay in the motor switches on (relay
E.OHT	OH Fault		contacts "open"), the inverter output can be stopped if those contacts
		operation (Note 3)
			had been entered into the inverter. If the relay contacts are reset
			automatically, the inverter will not restart unless it is reset.
			If a current not less than 150% (Note 4) of the rated inverter current
			flows in the motor, this function lowers the frequency until the load
E.OLT		During acceleration	current reduces to prevent the inverter from resulting in overcurrent
(When			shut-off. When the load current has reduced below 150%, this function
stall			increases the frequency again to accelerate and operate the inverter up
prevention	Stll Prev		to the set frequency.
operation			If a current not less than 150% (Note 4) of the rated inverter current
	STP
has			flows in the motor, this function lowers the frequency until the load
	(OL	During constant-speed
reduced			current reduces to prevent overcurrent shut-off. When the load current
	shown	operation
the			has reduced below 150%, this function increases the frequency up to
	during stall
running			the set value.
	prevention
frequency			If the regenerative energy of the motor has increased above the brake
	operation)
to 0. OL			capability, this function increases the frequency to prevent overvoltage
during stall			shut-off. If a current not less than 150% (Note 4) of the rated inverter
prevention		During deceleration	current flows in the motor, this function increases the frequency until
operation)			the load current reduces to prevent the inverter from resulting in
			overcurrent shut-off. When the load current has reduced below 150%,
			this function decreases the frequency again.
			・Stops the inverter output if the dedicated inboard option used in the
E.OPT	Option	Option alarm	inverter results in setting error or connection (connector) fault.
	Fault		・When the high power factor converter connection is selected, this
			alarm is displayed if AC power is connected to R, S, T.
E.OP1 to	Option slot		Stops the inverter output if a functional fault (such as communication
	alarm	Option slot alarm	error of the communication option) occurs in the inboard option loaded in
OP3
	1 to 3		any slot.
E. PE	Corrupt	Parameter error	Stops the output if a fault occurs in E2PROM which stores parameter
	Memry		settings.
			This function stops the inverter output if communication between
			inverter and PU is suspended, e.g. the operation panel or parameter unit
			is disconnected, when "2", "3", "16" or "17" is set in Pr. 75 "reset
	PU Leave	PU disconnection	selection/PU disconnection detection/PU stop selection". This function
E.PUE			stops the inverter output if the number of successive communication
	Out	occurrence
			errors is greater than the number of permissible retries when Pr. 121
			value is "9999" for RS-485 communication from PU connector.
			This function stops the inverter output if communication is broken for a
			period of time set in Pr. 122.
E.RET	Retry No	Retry count exceeded	If operation cannot be resumed within the number of retries set, this
	Over		function stops the inverter output.
E.LF	⎯⎯	Open output phase	This function stops the inverter output when any of the three phases
		protection	(U, V, W) on the inverter's output side (load side) opens.
			If the arithmetic operation of the built-in CPU does not end within a
E.CPU	CPU Fault	CPU error	predetermined period, the inverter self-determines it has an alarm and
			stops the output.
			When 24VDC power output from the PC terminal is shorted, this function
E.P24	⎯⎯	24VDC power output short	shuts off the power output. At this time, all external contact inputs
		circuit	switch off. The inverter cannot be reset by entering the RES signal. To
			reset, use the operation panel or switch power off, then on again.

25