GE ASTAT XL User Manual page 33

7.6.3.2 Pump stopping
The hydraulic characteristics of pump systems vary considerably. This variation means the ideal
deceleration profile and stop time will vary from application to application. The table provides
guidelines on selecting between Adaptive Control deceleration profiles, but we recommend testing the
three profiles to identify the best profile for the application.
Adaptive Stop Profile
Late Deceleration
Constant Deceleration
Early Deceleration
The first Adaptive Control stop will be a normal soft stop. This allows the ASTAT XL to learn the
characteristics of the connected motor. This motor data is used by the ASTAT XL during subsequent
Adaptive Control stops.
NOTE
Adaptive Control will control the load according to the programmed profile. Stopping current
will vary according to the selected deceleration profile and stop time.
If replacing a motor connected to a ASTAT XL programmed for Adaptive Control starting or
stopping, or if the starter has been tested on a different motor prior to actual installation, the
starter will need to learn the characteristics of the new motor. The ASTAT XL will automatically
re-learn the motor's characteristics if parameter 1A Motor Full Load Current or parameter 2L
Adaptive Control Gain is changed.
7.6.4 Brake
Brake reduces the time required to stop the motor.
During braking an increased noise level from the motor may be audible. This is a normal part of motor
braking.
When brake is selected, the ASTAT XL uses DC injection to slow the motor.
ASTAT XL braking:
• Does not require the use of a DC brake contactor
• Controls all three phases so that the braking currents and associated heating are evenly
distributed through the motor.
CAUTION
If the brake torque is set too high, the motor will stop before the end of the brake time and the motor
will suffer unnecessary heating which could result in damage. Careful configuration is required to
ensure safe operation of the starter and motor.
A high brake torque setting can result in peak currents up to motor DOL being drawn while the motor is
stopping. Ensure protection fuses installed in the motor branch circuit are selected appropriately.
CAUTION
Brake operation causes the motor to heat faster than the rate calculated by the motor thermal
model. If you are using brake, install a motor thermistor or allow sufficient restart delay
(parameter 5A).
Braking has two stages:
• Pre-brake: provides an intermediate level of braking to slow motor speed to a point where full
brake can be operated successfully (approximately 70% speed).
• Full brake: brake provides maximum braking torque but is ineffective at speeds greater than
approximately 70%.
ASTAT XL User Manual
Application
High head systems where even a small decrease in motor/pump speed
results in a rapid transition between forward flow and reverse flow.
Low to medium head, high flow applications where the fluid has high
momentum.
Open pump systems where fluid must drain back through the pump without
driving the pump in reverse.
DET-812
Fout! Stijl niet gedefinieerd.
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