GE Multilin M60 Motor Protection System 5-231
5 SETTINGS 5.7 CONTROL ELEMENTS
5
The M60 can control the transition of a motor start from reduced to full voltage. This feature uses motor load and a supervi-
sory timer to initiate a one second control signal (the REDUCED VOLT CTRL operand) that can be used to switch to full volt-
age. The feature can also assert a trip signal (the REDUCED VOLT OP operand) from the starting logic if the current or timer
transitions do not occur as expected. This transition may be defined as current only, current or timer, or current and timer as
described below.
Figure 5–117: REDUCED VOLTAGE STARTING CURRENT CHARACTERISTIC
All FlexLogic operands are asserted upon the initiation of a motor start. The REDUCED VOLT OP operand is set
when the transition timer expires if the motor load never exceeds the
REDUCED VOLT FLA setting and the motor sta-
tus is starting. The REDUCED VOLT CTRL operand is set when the transition timer expires and the motor load has
dropped below the motor full load current setting; that is, the motor status is not starting.
• REDUCED VOLTAGE STARTING: This setting enables and disabled the reduced voltage starting feature.
• TRANSITION MODE: This setting selects the reduced voltage starting transition method. The reduced voltage timer is
initiated at the beginning of a motor start; that is, when the motor status transitions from offline to starting. There are
three modes of transition:
– “Current Only”: When the motor load falls below the REDUCED VOLTAGE FLA setting prior to the expiration of the
reduced voltage timer, a transition will be initiated by asserting the
REDUCED VOLT CTRL operand for a period of
one second. Any contact output assigned to this operand will operate for this period of time. If the reduced voltage
timer expires prior to the motor load dropping below the
REDUCED VOLTAGE FLA setting, the REDUCED VOLT CTRL
operand does not change state and the REDUCED VOLT OP operand is asserted.
– “Current Or Timer”: When the motor load falls below the
REDUCED VOLTAGE FLA setting, or if the reduced voltage
timer expires, a transition will be initiated by asserting the
REDUCED VOLT CTRL operand for one second. Any con-
tact output assigned to this control signal will operate for this period of time.
– “Current And Timer”: A transition will be initiated by asserting the REDUCED VOLT CTRL operand for one second
when the reduced voltage timer expires and the motor load has dropped below the
REDUCED VOLTAGE FLA setting
prior to the expiration of the reduced voltage timer. If the reduced voltage timer expires prior to the motor load
dropping below the
REDUCED VOLTAGE FLA setting, the REDUCED VOLT CTRL operand does not change state and
the
REDUCED VOLT OP operand is asserted.
When the current falls below the
setting and/or the setting expires,
the REDUCED VOLT CTRL operand asserts for 1 second.
REDUCED VOLT
FLA REDUCED VOLT TIMER
Motor
current
(% FLA)
REDUCED VOLT FLA
setting
MOTOR FULL LOAD
AMPS setting
FlexLogic™
operand
states
signifies an
open transition
time
833752A1.CDR
MOTOR STARTING
REDUCED VOLT CTRL
MOTOR RUNNING
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