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CHAPTER 4: SETPOINTS
Thermal protection
setpoints
MM200 MOTOR MANAGEMENT SYSTEM – INSTRUCTION MANUAL
The following setpoints are available for thermal protection.
Standard Overload Curve
Range: 1 to 15 in steps of 1
Default: 4
This setpoint specifies the standard overload curve to the thermal characteristics of the
protected motor.
Overload Pickup Level
Range: 1.01 to 1.25 X FLA
Default: 4
This setpoint specifies the Overload Pickup Level for the unit to start.
Hot/Cold Safe Stall Ratio
Range: 1 to 100% in steps of 1
Default: 75%
This setpoint is used to control the hot/cold bias and RTD bias features. It specifies the
ratio of the rated hot safe stall time to the rated cold safe stall time as a percentage. A
value of "100%" disables the hot/cold bias feature.
Cool Time Constant Stopped
Range: 1 to 1000 minutes in steps of 1
Default: 30 minutes
This setpoint specifies the cooling time constant used by the thermal model when the
motor is stopped. Enter the time in minutes for the temperature to cool by 63% of the
difference between the initial value and ambient when the motor is stationary.
Cool Time Constant Running
Range: 1 to 1000 minutes in steps of 1
Default: 15 minutes
This setpoint specifies the cooling time constant used by the thermal model when the
motor is running. Enter the time in minutes for the temperature to cool by 63% of the
difference between the initial value and ambient when the motor is at speed.
Minimize Reset Time
Range: Enabled, Disabled
Default: Disabled
When set to "Disabled", the lockout condition following a thermal protection operation
will persist until the thermal capacity used has dropped to 15%. When set to "Enabled",
the lockout persists until the thermal capacity used has dropped to 2% below the
learned thermal capacity used at start (refer to the Thermal Start Inhibit for details).
Overload Reset Mode
Range: Manual, Auto
Default: Manual
If this setpoint value is "Auto", an automatic reset of overload lockouts occurs after the
motor has cooled as described above. When set to "Manual", the lockouts are replaced
with trips when the motor cools, the trips must be reset by the control panel, by remote
contact or by communications before the motor can be restarted.
PROTECTION ELEMENTS
4–19
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