Speed Motor - GE 869 Instruction Manual

PROTECTION

2-Speed Motor

2-Speed Thermal
Model
4–170
The two-speed motor feature provides proper protection for a two-speed motor where
there are two different full load values. If the two-speed motor feature is used, setpoint
Speed Motor Protection must be set to Enabled under
Also, assignable input for setpoint
must monitor for a contact closure. Contact closure signifies that the motor is in
> Setup
Speed 2; if the input is open, it signifies that the motor is in Speed 1. This allows the 869 to
determine which settings must be active at any given point in time.
Path:
Setpoints > Protection > Group1(6) > 2-Speed Motor > Speed2 Thermal Model
When the two-speed motor functionality is used, these settings allow the selection of the
proper parameters for the thermal model when the motor is switched to the second speed.
There is one thermal model in the 869, and it has inputs for overload conditions from
calculations at both speeds. As such, the accumulated thermal capacity is calculated from
overload contributions at each speed.
The algorithm integrates the heating at each speed into one thermal model using a
common thermal capacity used register value for both speeds.
Refer to the 2-Speed Thermal Model
second motor speed.
OVERLOAD CURVE
Range: Motor, Flexcurve A, Flexcurve B, Flexcurve C, Flexcurve D, IEC
Default: Motor
TD MULTIPLIER
Range: 1.00 to 25.00 in steps of 0.01 when thermal model curve is Motor
Default: 1.00
Range: 0.00 to 600.00 in steps of 0.01 when thermal model curve is Flexcurve
Default: 0.00
VOLT. DEPENDENT (VD) FUNCTION
Range: Disabled, Enabled
Default: Disabled
VD MIN MOTOR VOLTS
Range: 60 to 99% in steps of 1
Default: 80%
VD VOLTAGE LOSS
Range: Off, Any FlexLogic operand
Default: Off
VD STALL CURRENT @ MIN V
Range: 1.50 to 20.00 FLA in steps of 0.01
Default: 4.50 x FLA
VD STALL TIME @ MIN V
Range: 0.1 to 1000.0 in steps of 0.1
Default: 20.0 s
VD ACCEL. INTERSECT @ MIN V
Range: 1.50 to 20.00 in steps of 0.01
Default: 4.00 x FLA
VD STALL CURRENT @ 100% V
Range: 1.50 to 20.00 FLA in steps of 0.01
Default: 6.00 x FLA
Setpoints > System > Motor > Setup
under
Speed2 Motor Switch
section for details on settings for thermal model at the
869 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS
2-
Setpoints > System > Motor
.