McQuay RVSS14 Installation, Operation And Maintenance Manual page 56

Starters for centrifugal chillers low voltage, solid state and wye-delta medium/high voltage, solid state and across-the-line
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Int. Curr. (initial current)
Description
The initial current parameter is set as a percentage of the motor FLA parameter setting. The
initial current parameter sets the current that will initially reach the motor when a start is
commanded.
If the motor does not rotate within a few seconds after a start command, the initial current
should be increased. If the motor takes off too quickly after a start command, the initial
current should be decreased.
The initial current must be set to a value that is lower than the maximum current parameter
setting.
A typical setting for the initial current parameter is from 50% to 175%.
Values
The initial current is adjustable from 50% to 400% in 1% intervals.
Default
The default value for the initial current is 100%.
Max. Curr. (maximum current)
Description
The maximum current parameter is set as a percentage of the motor FLA parameter setting.
The maximum current parameter performs two functions. It sets the current for the end of the
ramp profile and sets the maximum current that is allowed to reach the motor while the motor
is being started.
If the ramp time expires before the motor has reached full speed, the starter will hold the
current at the maximum current level until the stall time expires, the motor reaches full speed,
or the overload trips.
Typically, the maximum current is set to 600% unless the power system or load dictates the
setting of a lower maximum current.
Values
The maximum current is adjustable from 100% to 600% in 1% intervals.
Default
The default value for the maximum current is 600%.
Ramp Time
Description
The ramp time sets the amount of time that it takes for the starter to linearly increase the
current from the initial current level to the maximum current level. A typical ramp time
setting is from 15 to 30 seconds.
Settings
The ramp time is adjustable from 0 to 120 seconds in 1 second intervals.
Default
The default value for the ramp time is 15 seconds.
Overload
Description
If there is more than one motor connected, the motor FLA should be set to the
sum of the connected motor full load.
amps.
Values
Class 1 to 40 in steps of 1.
56
IOMM Starter

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