Rockwell Automation 1395 DC Drive, 800-1250 Hp, FRN 5.XX-9.30 - Manual (Page 156)

Chapter 5
Programming Parameters
5-65
Parameter 729 – Field Fault Threshold [Fld Flt Thresh]
Internal units : 4096 = 1000h = 1 PU = 100% rated motor field
current
Programming Terminal units: Per cent rated field current
Minimum Value: 0%
Maximum Value: 100%
Default Value: 30%
Description: This parameter is used to set the threshold for activating
the motor loss fault in the CP fault word (parameter 101, bit 6).
Internally, if the field current reference (parameter #117) is greater
than the field current threshold (parameter #729) and the field current
feedback (parameter #118) is less than 10% of threshold, a field loss
fault occurs. A value of zero disables the field loss fault detection.
Parameter 730 – Field Failure Delay [Fld Failure Dly]
Internal units : Seconds x 10
Programming Terminal units: Seconds
Minimum Value: 0.1
Maximum Value: 5.0
Default Value: 1.0
Description: This parameter indicates the length of time that the field
current feedback value can deviate by more than 50% of field current
reference before a field loss condition is indicated.
Parameter 731 – Tach Loss CEMF [Tach Loss CEMF]
Internal Units: 4096 = 1000h = 100% of full CEMF
Programming Terminal Units: %
Minimum Value: 0 %
Maximum Value: 50%
Default Value: 10.01%
Description: This parameter sets the CEMF level, above which a
Tach (or encoder) Loss Fault will occur. CEMF is obtained from the
Armature Voltage Feedback level, less the calculated IR drop. Units
for this parameter are in percent of full CEMF. The velocity feedback
must also be less than the level set by parameter 732 for a Tach Loss
fault to be detected.
Parameter 732 – Tach Loss Velocity [Tach Loss Vel]
Internal Units: 4096 = 1000h = 100% base motor speed
Programming Terminal Units: %
Minimum Value: 0.244 %
Maximum Value: 50%
Default Value: 2.002%
Description: This parameter sets the velocity feedback level, below
which a Tach (or encoder) Loss Fault will occur. Units for this
parameter are in percent of base motor speed. The CEMF level must
also be greater than the level set by parameter 731 for a Tach Loss
fault to be detected.