Rockwell Automation 1756-DMF30 ControlLogix Drive Module - Manual (Page 151)

Publication 1756-UM522B-EN-P - February 2003
1756-DMD30 Specific Information B-71
338 Mtr I2T Spd Min
Sets the minimum speed for the motor overload (I
2
T) function.
The value indicates minimum speed below the minimum
current threshold [Mtr I2T Curr Min], and these are the first
current/speed breakpoint. From this point the current threshold
is linear to the value specified by the motor service factor
[Service Factor].
Units:
Default:
Min:
Max:
Type:
File:
Group: P.U.
1
0.05
1
Non-Linkable, Read-Write, Floating Point
Dynamic Control
Overload Protect
Motor Overload curve when parameter 338 [Mtr I2T Spd Min] is Less Than 1.0
Motor Overload curve when parameter 338 [Mtr I2T Spd Min] Equals 1.0
339 Mtr I2T Calibrat
Sets the current calibration level for the motor overload (I
2
T)
function. The value indicates the current level that the drive
will fault at this current in 60 seconds.
Units:
Default:
Min:
Max:
Type:
File:
Group: P.U.
2
1.1
4
Non-Linkable, Read-Write, Floating Point
Dynamic Control
Overload Protect
340 Mtr I2T Trp ThrH
Displays the trip threshold current for the motor overload (I
2
T)
function. The value depends on the motor speed, and is
calculated from the minimum current, parameter 337 [Mtr I2T
Curr Min], the minimum speed, parameter 338 [Mtr I2T Spd
Min] and the motor service factor, parameter 336 [Service
Factor].
Units:
Default:
Min:
Max:
Type:
File:
Group: P.U.
1.15
0.05
2
Non-Linkable, Read Only, Floating Point
Dynamic Control
Overload Protect
No. Name
Description Values
When motor current exceeds the
value of the curve,Mtr OL Outpt
integrates. If the value in Mtr OL
Outpt reaches 1.0, a motor overload
exception event occurs. The value
of Mtr OL Outpt is visable in
parameter 330 [Fault TP Data] when
the value of parameter 329 [Fault TP
Sel] equals 13.
P336 [Service Factor]
Current
P337 [Mtr I2T Curr Min]
Speed
P338 [Mtr I2T Spd Min] Base Speed (1.0)
P336 [Service Factor]
Current
Speed
When the value of parameter 338
[Mtr I2T Spd Min] equals 1.0, the
curve is flat - at the value of rated
motor current times the value of
parameter 336 [Service Factor]. If
motor current exceeds the value of
the curve [Service Factor], the value
of Mtr OL Outpt integrates.