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V&T Technologies Co., Ltd.
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Chapter 7 Fault Diagnosis
108
Chapter 7 Fault Diagnosis
7.1 List of Fault and Alarm Information
E5
−
H serial inverter is equipped with complete protection functions to provide efficient protection while
utilizing its performance sufficiently. Some failure instructions may be displayed during operation.
Compare the instructions with the following table and analyze, decide the causes and solve failures.
For damages on units or questions that can’t be resolved, please contact with local distributors/agents,
service centers or manufacturer for solutions.
Failure
No.
Failure
code
Failure
description
Potential causes
Solutions
1
E.oc1
Over current
protection when
acceleration
operation
Low grid voltage
Check input power supply
Startup too fast during motor operation
Restart after the motor stops
rotating
Rotating inertial of load is very large and shock
load is very heavy
Increase the acceleration time
and reduce the occurrences of
sudden change of load
Improper setting of motor parameters
Set motor parameters properly
Set start
−
up frequency too high
Decrease start
−
up frequency
Acceleration time is too short
Lengthen acceleration time
Set V/F curve ratio too large
Adjust V/F curve setting and
torque boost
Power level of inverter is small
Replace with inverter with proper
model
2
E.oc2
Over current
protection when
deceleration
operation
Low grid voltage
Check input power supply
Rotating inertial of load is too large
Choose appropriate energy
braking components
Improper setting of motor parameters
Set motor parameters properly
Deceleration time is too short
Lengthen deceleration time
Power level of inverter is small
Replace to inverter with proper
model
3
E.oc3
Over current
protection when
operation with
constant speed
Sudden change of load during operation
Decrease load’s abrupt
frequency change and amplitude
Improper setting of motor parameters
Set motor parameters properly
Power level of inverter is small
Replace to inverter with proper
model
4
E.oV1
Over voltage
protection when
acceleration
operation
Motor short to ground
Check motor wiring
Abnormal input power supply voltage
Check input power supply
Fast start
−
up again when motor operates with
high speed
Start again after the motor stop
rotating
5
E.oV2
Over voltage
protection when
deceleration
operation
Motor short to ground
Check motor wiring
Rotating inertial of load is too large
Choose appropriate energy
braking components
Deceleration time is too short
Lengthen deceleration time
6
E.oV3
Over voltage
protection when
operation with
constant speed
Motor short to ground
Check motor wiring
Abnormal input power supply
Check input power supply
Rotating inertial of load is too large
Choose appropriate energy
braking components
7
E.PCU
Interference
protection
Severely Interfered by exterior signal
Ask professional technicians to
maintain
8
E.rEF
Abnormal
comparison
benchmark
Loose connection of connectors inside the
inverter
Ask professional technicians to
maintain
Abnormal internal switching power supply
Seek for technical support
Abnormal signal sampling and comparison
circuit
Seek for technical support