Digital Operator Display Minor Fault NameMotor thermostat wiring is faulty (PTCinput). Repair the PTC input wiring.There is a fault on the machine side (e.g.,the machine is locked up).• Check the status of the machine.• Remove the cause of the fault.Motor has overheated.• Check the load size, accel/decel times, and cycle times.• Decrease the load.• Increase accel and decel times (C1-01 to C1-04).• Adjust the preset V/f pattern (E1-04 through E1-10). This involves reducing E1-08 and E1-10.Note: Refrain from lowering E1-08 and E1-10 excessively to prevent a reduction in load toleranceat low speeds.• Check the motor-rated current.• Enter motor-rated current on motor nameplate (E2-01).• Ensure the motor cooling system is operating normally.• Repair or replace the motor cooling system.Digital Operator Display Fault NameoH4Motor Overheat Fault (PTC Input)• The motor overheat signal to analog input terminal A1, A2, or A3 exceeded the fault detection level.• Detection requires setting multi-function analog inputs H3-02, H3-10, or H3-06 to E.Cause Possible SolutionMotor has overheated• Check the size of the load, the accel/decel times, and the cycle times.• Decrease the load.• Increase the acceleration and deceleration times (C1-01 through C1-04).• Adjust the preset V/f pattern (E1-04 through E1-10) by reducing E1-08 and E1-10.• Do not set E1-08 and E1-10 too low. This reduces load tolerance at low speeds.• Check the motor rated current.• Enter the motor rated current to parameter E2-01 as indicated on the motor nameplate.• Ensure the motor cooling system is operating normally.• Repair or replace the motor cooling system.Digital Operator Display Minor Fault NameovDC Bus OvervoltageThe DC bus voltage exceeded the trip point.• For 200 V class drives: approximately 410 V• For 400 V class drives: approximately 820 V (740 V when E1-01 is less than 400)• For 600 V class drives: approximately 1040 VCause Possible SolutionsSurge voltage present in the drive inputpower.• Install a DC link choke or an AC reactor.• Voltage surge can result from a thyristor convertor and a phase advancing capacitor operating on the samedrive input power system.The motor is short-circuited. • Check the motor power cable, relay terminals and motor terminal box for short circuits.• Correct grounding shorts and turn the power back on.Ground current has overcharged the maincircuit capacitors via the drive input power.Noise interference causes the drive tooperate incorrectly.• Review possible solutions for handling noise interference.• Review section on handling noise interference and check control circuit lines, main circuit lines and groundwiring.• 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 NamePASS MEMOBUS/Modbus Comm. Test Mode CompleteCause Possible SolutionsMEMOBUS/Modbus test has finishednormally. This verifies that the test was successful.6.5 Alarm Detection316 YASKAWA SIEP YAIP1U 01C AC Drive - P1000 Technical Manual
