Rockwell Automation 20B PowerFlex 700 AC Drives Vector Control (v4.001 and up) - Manual (Page 123)

Rockwell Automation Publication 20B-UM002G-EN-P - July 2014 123
Application Notes Appendix C
Motor Overload Memory
Retention Per 2005 NEC Firmware version 4.002 or greater – has the ability to retain the motor overload
count at power down per the 2005 NEC motor overtemp requirement. To
Enable/Disable this feature, refer to the table below. Once Enabled, the value for
[Testpoint 1 Sel] can be changed.
Firmware version 6.002 or greater – when bit 0 of [Motor OL Mode], parameter
50 is set to “1,” the value of [Motor OL Count], parameter 220 is maintained
through a power cycle or drive reset. This is an enhanced version of the v4.002
Motor Overload Memory function. The testpoint method will still work, but the
preferred method is to set [Motor OL Mode], parameter 50.
Overspeed Overspeed Limit is a user programmable value that allows operation at maximum
speed, but also provides an “overspeed band” that will allow a speed regulator
such as encoder feedback or slip compensation to increase the output frequency
above maximum speed in order to maintain maximum motor speed.
Figure 9 illustrates a typical Custom V/Hz profile. Minimum Speed is entered in
Hertz and determines the lower speed reference limit during normal operation.
Maximum Speed is entered in Hertz and determines the upper speed reference
limit. The two “Speed” parameters only limit the speed reference and not the
output frequency.
Figure 9 - Custom V/Hz Profile
The actual output frequency at maximum speed reference is the sum of the speed
reference plus “speed adder” components from functions such as slip
compensation.
The Overspeed Limit is entered in Hertz and added to Maximum Speed and the
sum of the two (Speed Limit) limit the output frequency. This sum (Speed
Limit) must is compared to Maximum Frequency and an alarm is initiated which
prevents operation if the Speed Limit exceeds Maximum Frequency.
Overload Retention [Testpoint 1 Sel], param 234 [Testpoint 1 Data], param 235
Enable “629” “1”
Disable “499” (1)
(1) Default setting.
“0” (1)
Frequency
Output
Voltage
Overspeed
Limit
Frequency Trim
due to Speed
Control Mode
Maximum
Voltage
Motor NP
Voltage
Run
Boost
Break
Voltage
Start
Boost
Allowable Output Frequency Range - Normal Operation
Allowable Speed Reference Range
Allowable Output Frequency Range -
Bus Regulation or Current Limit
Maximum
Frequency
Motor NP Hz 0 Break
Frequency
Maximum
Speed
Minimum
Speed
Output
Frequency
Limit
(lower limit on this range can be 0 depending on the value of Speed Adder)