Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE - Manual (Page 302)

10-60 TROUBLESHOOTING
1557-UM050F-EN-P – June 2013
The factory default for the variable “External Fault Class 1” is 0000 hex and the default value for
“External Fault Class 2” is FFFF hex, therefore, the default class for all the config. fault / warning input
is class 2
“ramp down trip”.
If both, External Fault Class 1 and 2 parameters were set to 0000 hex all of the 16 config. faults /
warnings would be class 3
“warnings”.
If External Fault Class 1 was set to FFFF hex regardless of the value of External Fault Class 2, all of the
config.fault / warnings would be class 1
“immediate trips”.
Note: Several values for External Fault Class 1 and 2 will produce the same result due to the way a class
1 fault is determined and whether or not the particular faults are turned off.
Included is an insert from the manual that includes the External Fault Class 1 and 2 parameter
descriptions.
External Fault Class 1 [Ext flt class 1]
Linear number:
230
Minimum value: 0000 Hex
Maximum value: FFFF Hex
Default value: 0000 Hex
This parameter specifies which of the external faults are Class 1 faults. It is bit encoded the same as
parameter “External Fault Input”.
This parameter and the following parameter taken together specify the class of each of the 16 external
faults as shown in the following table:
Class Ext Flt Class 1 Ext Flt Class 2
1 1 0 or 1
2 0 1
3 0 0
Note: Class 1 faults cause the drive to trip immediately. Class 2 faults cause the drive to decelerate to a
stop at the normal ramp rate before tripping. Class 3 faults are only warnings and cause no action to be
taken.
External Fault Class 2 [Ext flt class 2]
Linear number:
231
Minimum value: 0000 Hex
Maximum value: FFFF Hex
Default value: FFFF Hex
This parameter specifies which of the external faults are Class 2 faults. It is bit encoded the same as
parameter “External Fault Input”. For more information refer to the description of the previous parameter.