Motor Start Supervision - GE M60 UR Series Instruction Manual

5 SETTINGS
a) MAIN MENU

PATH: SETTINGS CONTROL ELEMENTS
 START SUPERVISION

MESSAGE
MESSAGE
The motor start supervision feature consists of three elements that guard against excessive starting duty. These elements
are in addition to the start inhibit that could be imposed by the thermal model. A method to prevent starting is by wiring an
M60 output contact actuated by motor start supervision elements in the motor energizing control circuit. The output contact
changes state only when the motor is stopped to accommodate control circuits that must be continuously energized such
as a contactor.
The three elements of motor start supervision are:
1. Maximum starting rate (starts per hour): This element defines the number of starts attempts allowed in a program-
mable time interval. Only the number of re-start attempts during the interval is controlled and not the time in between.
The latter is controlled by the time between starts element. When the motor is stopped after the last allowed start the
energizing or closing control circuit is disabled until the end of the defined interval. Every start initiate a new interval in
which the start number is limited A typical starting frequency is three starts per hour.
2. Time between starts: This function enforces a programmable minimum time duration between two successive starts
attempts. A time delay is initiated with every start and if the motor is stopped a restart is not allowed until the specified
interval has lapsed.
3. Restart Delay: The restart delay function defines a programmable delay after a motor has stopped before it can be
started again. It allows load interruption transient conditions such as down-hole pump applications where gravitational
force causes reverse rotation to subside. Starting when the load is reversing could cause damage to the motor or
pump.
GE Multilin

START SUPERVISION
 MAXIMUM STARTING
 RATE (STARTS/HR)
 TIME BETWEEN
 STARTS
 RESTART DELAY

M60 Motor Protection System
5.7 CONTROL ELEMENTS

5.7.7 MOTOR START SUPERVISION

See page 5-228.
See page 5-229.
See page 5-230.
5
5-227