GE M60 Instruction Manual

Also see for M60: Communications manual Communications guide Instruction manual Instruction manual

Contents

CHAPTER 5: SETTINGS CONTROL ELEMENTSM60 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 5-24155.8.7 Motor start supervision5.8.7.1 MenuSETTINGS  CONTROL ELEMENTS  START SUPERVISIONThe motor start supervision feature consists of three elements that guard against excessive starting duty. These elementsare in addition to the start inhibit that can be imposed by the thermal model. A method to prevent starting is by wiring anM60 output contact actuated by motor start supervision elements in the motor energizing control circuit. The outputcontact changes state only when the motor is stopped to accommodate control circuits that must be continuouslyenergized, such as a contactor.The three elements of motor start supervision are• Maximum starting rate (starts per hour) — This element defines the number of start attempts allowed in aprogrammable time interval. Only the number of restart attempts during the interval is controlled and not the timebetween. The latter is controlled by the time between starts element. When the motor is stopped after the last allowedstart, the energizing or closing control circuit is disabled until the end of the defined interval. Every start initiates a newinterval in which the start number is limited. A typical starting frequency is three starts per hour.• Time between starts — This function enforces a programmable minimum time duration between two successive startattempts. A time delay is initiated with every start, and if the motor is stopped a restart is not allowed until thespecified interval has lapsed.• Restart delay — The restart delay function defines a programmable delay after a motor has stopped before it can bestarted again. It allows load interruption transient conditions, such as down-hole pump applications wheregravitational force causes reverse rotation to subside. Starting when the load is reversing can cause damage to themotor or pump.5.8.7.2 Maximum starting rateSETTINGS  CONTROL ELEMENTS  START SUPERVISION  MAXIMUM STARTING RATEThe element can be programmed to perform the classical monitoring function of Starts Per Hour. However, time intervalunits specified by the START/HR TIME INTERVAL setting are in minutes for increased flexibility. The STARTS/HR MAX NUMBER OFSTARTS setting specifies the start attempt number limit during the interval. The time unit and ranges accommodate thestarting requirements of large direct-on-line motors.The element asserts the following three FlexLogic operands: START SUPERVISION   MAXIMUM STARTING RATE (STARTS/HR)See below  TIME BETWEEN STARTSSee page 5-242  RESTART DELAYSee page 5-243 MAXIMUM STARTING RATE (STARTS/HR)  STARTS/HR FUNCTION:DisabledRange: Disabled, Enabled STARTS/HR TIMEINTERVAL: 60 minRange: 1 to 300 minutes in steps of 1 STARTS/HR MAX NUMBEROF STARTS: 3Range: 1 to 16 in steps of 1 STARTS/HR BLOCK:OffRange: FlexLogic operand STARTS/HR TARGET:Self-ResetRange: Self-Reset, Latched, Disabled STARTS/HR EVENTS:DisabledRange: Disabled, Enabled