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

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Image 36
Mitsubishi Electronics FR-A500L instruction manual Oht