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Digital Operator Display
Minor Fault Name
Parameter settings are not appropriate.
Check parameters L6-05 and L6-06.
YES
There is a fault on the machine side (e.g., the
machine is locked up).
• Check the status of the machine being used.
• Remove the cause of the fault.
Digital Operator Display
Minor Fault Name
oL5
Mechanical Weakening Detection 1
Overtorque occurred, matching the conditions specified in L6-08.
Cause
Possible Solution
Minor Fault
(H2-
oo
= 10)
Overtorque occurred, triggering the
mechanical weakening level set to L6-08.
Check for the cause of mechanical weakening.
YES
Digital Operator Display
Minor Fault Name
oS
Overspeed (for Simple V/f with PG)
Pulse input (RP) indicates that motor speed feedback exceeded F1-08 setting.
Cause
Possible Solution
Minor Fault
(H2-
oo
= 10)
Overshoot or undershoot is occurring.
• Adjust the gain by using the pulse train input parameters (H6-02 through H6-05).
• Adjust the speed feedback accuracy.
• Increase the settings for C5-01 (Speed Control Proportional Gain 1) and reduce C5-02
(Speed Control Integral Time 1).
YES
PG pulse settings are incorrect.
Set the H6-02 (Pulse Train Input Scaling) to the frequency of PG pulses at maximum motor
speed.
Parameter settings are inappropriate.
Check the setting for the overspeed detection level and the overspeed detection time (F1-08
and F1-09).
Digital Operator Display
Minor Fault Name
ov
DC Bus Overvoltage
The DC bus voltage exceeded the trip point.
For 200 V class: approximately 410 V
For 400 V class: approximately 820 V (740 V when E1-01 < 400)
Cause
Possible Solution
Minor Fault
(H2-
oo
= 10)
Surge voltage present in the drive input power.
• Install an AC reactor or DC link choke.
• Voltage surge can result from a thyristor convertor and a phase advancing capacitor
operating on the same drive input power system.
YES
• The motor is short-circuited.
• Ground current has over-charged the main
circuit capacitors via the drive input power.
• Check the motor power cable, relay terminals and motor terminal box for short circuits.
• Correct grounding shorts and turn the power back on.
Noise interference causes the drive to operate
incorrectly.
• Review possible solutions for handling noise interference.
• Review section on handling noise interference and check control circuit lines, main
circuit lines and ground wiring.
• If the magnetic contactor is identified as a source of noise, install a surge protector to
the MC coil.
Set number of fault restarts (L5-01) to a value other than 0.
Digital Operator Display
Minor Fault Name
PASS
MEMOBUS/Modbus Comm. Test Mode Complete
Cause
Possible Solution
Minor Fault
(H2-
oo
= 10)
MEMOBUS/Modbus test has finished
normally.
This verifies that the test was successful.
No output
Digital Operator Display
Minor Fault Name
PGo
PG Disconnect (for Simple V/f with PG)
Detected when no PG pulses received for a time longer than setting in F1-14.
Cause
Possible Solution
Minor Fault
(H2-
oo
= 10)
6.5 Alarm Detection
288
YASKAWA ELECTRIC SIEP C710606 18F YASKAWA AC Drive – V1000 Technical Manual