Rockwell Automation Publication 20A-UM001N-EN-P - July 2013 115
Application Notes Appendix C
Motor Overload Memory
Retention Per 2005 NEC
The PowerFlex 70 EC (firmware revision 3.002 or later) has the ability to retain
the motor overload count at power down per the 2005 NEC motor overtemp
requirement. A parameter has been added to provide this functionality. To
enable/disable this feature, refer to the information below.
Start At Powerup
When Start At PowerUp in 2-wire control is configured, the drive starts if all
start permissive conditions are met (within 10 seconds of drive power being
applied), and the terminal block start input (Run, Run Forward or Run Reverse
for 2-wire) is closed. An alarm is annunciated from application of power until the
drive actually starts, indicating the powerup start attempt is in progress.
The powerup start attempt is aborted if any of the following occurs anytime
during the 10-second start interval:
• A fault condition occurs
• A Type 2 alarm condition occurs
• The terminal block programmed enable input is opened
• All terminal block run, run forward, or run reverse, inputs are canceled
• A Stop request (from any source) is received
If the drive has not started within the 10 second interval, the powerup start
attempt is terminated.
Overspeed
Overspeed Limit is a user programmable value that enables operation at
maximum speed, but also provides an overspeed band that enables a speed
regulator, such as encoder feedback or slip compensation, to increase the output
frequency above maximum speed to maintain maximum motor speed.
The figure below 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 limit only the speed reference, not the
output frequency.
File B
Group
No.
Parameter Name and Description
See page 14 for symbol descriptions
Values
Related
MOTOR CONTROL (File B)
Motor Data
050 [Motor OL Mode]
If “0,” [Motor OL Count], P220 is reset to zero by a drive reset or a power cycle. If “1,”
the value is maintained. A “1” to “0” transition resets [Motor OL Count], P220 to zero.
xxx 0xxxxxxxxxxxx
10 01234567891112131415
1 = Enabled
0 = Disabled
x = Reserved
Bit #
Factory Default Bit Values
Pwr Cyc Ret
Nibble 1Nibble 2Nibble 3Nibble 4
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