Mitsubishi Electric Melservo-J4 Instruction Manual page 93

Alarm No.: 7D Name: Safety observation error
 The safety observation function detected an error.
Alarm content
Detail Detail name Cause
No.
7D.1 Stop (1)
observation
error
(2)
(3)
(4)
(5)
(6)
(7)
Check method
During activation of Check that the actual
SOS function, the servo motor position is
position of the servo higher than the setting
motor has changed by value of [Pr. PSA05].
more than the SOS
allowance value set by
parameter.
During activation of The actual servo motor
SOS function, the servo speed is higher than the
motor speed has setting value of [Pr.
changed by larger than PSA04].
the SOS allowance
value set by parameter,
and that state has
continued for longer
than the set time
(specified by [Pr.
PSA15]).
During activation of Check if the command
SOS function, the from the controller is over
speed command has the standstill speed set in
changed by larger than [Pr. PSA04].
the SOS allowance
value set by parameter,
and that state has
continued for longer
than the set time
(specified by [Pr.
PSA15]).
An encoder is Replace the servo motor,
malfunctioning. and then check the
repeatability.
The functional safety Replace the functional
unit is malfunctioning. safety unit, and then
check the repeatability.
The servo amplifier is Replace the servo
malfunctioning. amplifier, and then check
the repeatability.
Something near the Check the noise, ambient
device caused it. temperature, vibration,
etc.
Check result
The travel distance of the
servo motor is larger than
the setting value in [Pr.
PSA05].
The travel distance of the
servo motor is smaller
than the alarm detection
level.
The servo motor speed is
higher than the setting
value in [Pr. PSA04].
The servo motor speed is
higher than the setting
value in [Pr. PSA15] and
equal to or lower than
that in [Pr. PSA04].
The command from the
controller is over the
setting valued in [Pr.
PSA04].
The command from
controller is higher than
the setting value in [Pr.
PSA15] and equal to or
lower than that in [Pr.
PSA04].
It is not repeatable.
It is repeatable.
It is not repeatable.
It is repeatable.
It is not repeatable.
It is repeatable.
There is a problem in the
surrounding.
1 TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
Action Target
Review the alarm level. [A]
[B]
[GF]
Check (2).
Review the parameter
setting.
Check (3).
Check the operation
pattern.
Check (4).
Replace the servo motor.
Check (5).
Replace the functional
safety unit.
Check (6).
Replace the servo motor.
Check (7).
Take countermeasures
against its cause.
1.4 Remedies for alarms
1
91