User Manual
EM303B General Purpose Inverter
164
10
Troubleshooting
10.1
Faults
When anything unexpected happens, the corresponding trip code and parameters will be
displayed on the keypad, fault relay is on and fault output terminal is on, inverter output stops.
When fault occurs, if the motor is running, it will coast to stop. See Table 9-1 for EM303B
fault trips and troubleshooting.
Table 9-1 EM303B Fault Trips and Troubleshooting
Trip
Code
Trip
Cause
Corrective Action
SC
Short
Circuit
1. Short circuit between
inverter output phases, or
between the output phases and
ground.
2. IGBT is damaged.
3. On-site interference.
1. Check if there is a short
circuit.
2. Check, take corrective
actions, and then reset.
2. Technical support is
required.
HOC
Instantaneous
Overcurrent
1. Short circuit between
inverter output phases or
between the output phases and
ground.
2. The
acceleration/deceleration time
is too short.
3. In V/F control mode, the
setting value of torque boost is
too big.
4. The motor is rotating when
inverter starts.
5. The capacity of motor
exceeds that of inverter, or the
load the too heavy.
1. Check, take corrective
actions, and then reset.
2. Prolong
acceleration/deceleration
time
3. Reduce setting value of
torque boost.
4. Set speed search start
enabled, or start DC brake.
5. Replace with applicable
motor or inverter.
SOC
Stable Overcurrent
HOU
Instantaneous
Overvoltage
1. Deceleration time is too
short. The motor regenerative
energy is too much.
2. Power supply voltage is too
high.
1. Prolong deceleration time.
2. Install applicable braking
unit and braking resistor.
3. Lower the power supply
voltage to the rated voltage.
SOU
Stable Overvoltage
1. Voltage of power grid is too
high.
2. Deceleration time is too
short.
1. Lower voltage to the rated
voltage.
2. Prolong the deceleration
time.