Yaskawa Z1000 AC Drive HVAC - Manual (Page 216)

Motor 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 Name
ov
DC Bus Overvoltage
The DC bus voltage exceeded the trip point.
For 600 V class drives: approximately 1040 V
Cause Possible Solutions
Surge voltage present in the drive input
power.
• 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 same
drive 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 main
circuit capacitors via the drive input power.
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 Solutions
MEMOBUS/Modbus test has finished
normally.
This verifies that the test was successful.
Digital Operator Display Minor Fault Name
SE
MEMOBUS/Modbus Communication Test Mode Error
Note: This alarm will not trigger a multi-function output terminal that is set for alarm output
(H2- = 10).
Cause Possible Solutions
A digital input set to 67H (MEMOBUS/
Modbus test) was closed while the drive
was running.
Stop the drive and run the test again.
Digital Operator Display Minor Fault Name
TrPC
IGBT Maintenance Time (90%)
IGBTs have reached 90% of their expected performance life.
Cause Possible Solutions
IGBTs have reached 90% of their expected
performance life.
Replace the drive.
Digital Operator Display Minor Fault Name
Uv
Undervoltage
One of the following conditions was true when the drive was stopped and a Run command was entered:
• DC bus voltage dropped below the level specified in L2-05.
• Contactor to suppress inrush current in the drive was opened.
• Low voltage in the control drive input power. This alarm outputs only if L2-01 is not 0 and DC bus voltage
is under L2-05.
Cause Possible Solutions
Phase loss in the drive input power. Check for wiring errors in the main circuit drive input power. Correct the wiring.
5.5 Alarm Detection
216 YASKAWA ELECTRIC TOEP YAIZ1U 03A YASKAWA AC Drive – Z1000 User Manual