Emerson E300 Series Design Manual page 465

Safety Product Mechanical
information information installation
Trip
OHt dc bus DC bus over temperature
OHt DC bus trip indicates a DC bus component over temperature based on the software thermal model. The drive includes
a thermal protection system to protect the DC bus components within the drive, this includes the effects of the output
current and DC bus ripple. The estimated temperature is displayed as a percentage of the trip level in parameter
Percentage Of DC Link Thermal Trip Level (J78). If this parameter reaches 100 % then an OHt DC bus trip is initiated. The
drive will attempt to stop the motor before tripping. If the motor does not stop in 10 seconds the drive trips immediately.
Control system
Recommended actions:
• Check the AC power supply voltage level
• Check the AC power supply voltage balance
• Check the DC bus voltage ripple level
27
• Reduce motor loading
• Check the output current stability and if unstable;
• Check the motor map settings within the drive (parameters B06, B02, B07, B03, B04, B05), all modes
• Slip Compensation Enable (B10), (Open loop)
• Select fixed boost mode, parameter B09 (Open loop)
• Disconnect load and complete a rotating autotune, Motor Autotune (B11)
• Autotune the rated speed, parameter B07 (Open loop) parameter B25 (RFC-A)
• Reduce the speed loop gains, parameters I01, I02, I06 and I07 run and stop (Closed loop operation)
• Add a speed feedback filter parameter C09 (Closed loop operation)
• Add a current demand filter, parameters I05, I10 run and stop
• Check position feedback signals for noise with an oscilloscope (Closed loop operation)
• Check encoder mechanical coupling (Closed loop operation)
• Reduce duty cycle
OHt Inverter Inverter over temperature based on thermal model
OHt Inverter trip indicates an IGBT junction over-temperature has been detected based on the software thermal model.
Control system
Recommended actions:
21
• Check AC power supply input phases present and balanced
• Check DC bus ripple
• Check for motor instability
• Reduce acceleration / deceleration rates
• Reduce the maximum operating switching frequency
• Reduce motor load
• Reduce duty cycle
OHt Power Power stage over temperature
OHt Power trip indicates that a power stage over-temperature has been detected. From the sub-trip 'xxyzz', the thermistor
location is identified by 'zz'.
OHt Power is detected at >= 90 % of the maximum threshold on starting a new travel i.e. exiting from Elevator Software
State (J03) = 0 to 1.
If during travel 100 % is reached the drive will trip immediately, where the location of the out of range temperature is
indicated by the sub-trip number as detailed in the table below:
Power system
Recommended actions:
22 • Check enclosure / drive fans are still functioning correctly
• Check enclosure ventilation paths, door filters
• Check correct drive size for the application, load correct
• Force heatsink cooling fans to run at maximum speed
• Increase enclosure ventilation
• Decrease acceleration / deceleration rates
• Reduce motor load
• Reduce duty cycle
• Reduce the drive switching frequency
• Use a drive with larger current / power rating
If the temperature is >= 90 % of the maximum then Global Warning (L04) = On (1) indicating that there is a thermal
issue and on the next start the elevator will trip OHt Power.
E300 Design Guide
Issue Number: 1
Electrical Getting
User Menu A Commissioning
installation started
Source xx
00
Source xx
00
Source xx
01
Advanced
Parameters
Diagnosis
y zz
2 00 DC bus thermal model gives trip with sub-trip 0
y zz
1 00 Inverter thermal model gives (OHt Inverter) trip with sub-trip 0
y zz
0 zz Thermistor location in the drive defined by zz
Diagnostics Optimization CT MODBUS RTU Technical Data
Description
Description
Description
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