BENSHAW RediStart MX3 Series, User Manual

Page: 94 / 238

86
6 - PARAMETER DESCRIPTION
Description Coast:
A coast to stop should be used when no special stopping requirements are necessary; Example: crushers, balls
mills, centrifuges, belts, conveyor. The bypass contactor is opened before the SCRs stop gating to reduce
wear on the contactor contacts.
Voltage Decel:
In this mode, the starter linearly phases-back the SCRs based on the parameters Decel Begin Level, Decel End
Level, and Decel Time.
TruTorque Decel:
In this mode, the starter linearly reduces the motor torque based on the Decel End Level and Decel Time.
DC Brake:
In this mode the starter provides D.C. injection for frictionless braking of a three phase motor.
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NOTE: The MX
3
stops the motor when any fault occurs. Depending on the application, it may be
desirable for the motor to be stopped in a controlled manner (Voltage Decel, TT Decel or D.C. Braking)
instead of being allowed to coast to a stop when this occurs. This may be achieved by setting the Controlled
Fault Stop (PFN 25) parameter to On. Be aware however that not all fault conditions allow for a controlled
fault stop.
See Also Decel Begin Level parameter (CFN16) on page 86.
Decel End Level parameter (CFN17) on page 87.
Decel Time parameter (CFN18) on page 87.
Deceleration Ramp Profile (CFN19) on page 88.
DC Brake Level (CFN20) on page 88.
DC Brake Time (CFN21) on page 89.
DC Brake Delay (CFN22) on page 89.
Controlled Fault Stop Enable (PFN25) on page 103.
Digital Input Configuration(I/O 01 - 08) on page 111.
Relay Output Configuration (I/O 10 - 15) on page 112.
Theory of Operation section 7.4, Deceleration Control on page 157.
Theory of Operation section 7.5, Braking Controls on page 159.
Decel Begin Level CFN 16
LCD Display
Range
1 – 100% of phase angle firing
(Default 40%)
Description
Stop Mode (CFN15) set to Voltage Deceleration:
The voltage deceleration profile utilizes an open loop S-curve voltage ramp profile. The Decel Begin Level
parameter sets the initial or starting voltage level when transferring from running to deceleration. The
deceleration beginning level is not a precise percentage of actual line voltage, but defines a point on the
S-curve deceleration profile.
A typical voltage decel begin level setting is between 30% and 40%. If the motor initially surges (oscillates)
when a stop is commanded, decrease this parameter value. If there is a sudden drop in motor speed when a
stop is commanded, increase this parameter value.
Stop Mode (CFN15) set to TruTorque Deceleration:
Not used when the Stop Mode parameter is set to TruTorque Decel. The TruTorque beginning deceleration
level is automatically calculated based on the motor load at the time the stop command is given.
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NOTE: It is important that the FUN06 - Rated Power Factor parameter is set properly so that the actual
deceleration torque levels are the levels desired.
CFN: Decel Begin
16
40 %