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CONTROL ELEMENTS
Stop/start control element
4–26
Field 2W/3W
Range: 2W, 3W
Default: 3W
Two-wire or three-wire controls selection. If in the two-wire mode, all field start contact
inputs being open will be treated as a field stop control. For reversing and two-speed
starter configurations, both start inputs open is treated as a field stop control.
MCC Start Ctrl
Range: Enabled, Disabled
Default: Enabled
Sets whether start commands are accepted from the control panel.
MCC Stop Mode
Range: Always Enabled, Follow Ctrl Mode
Default: Always Enabled
If set to "Always Enabled", control panel stops will always be honoured, irrespective of
the
setpoint, auto/manual mode, and permissive. If set to "Follow Ctrl
MCC Start Ctrl
Mode", control panel stops will be supervised by auto/manual and by MCC permissive in
the same manner as the starts.
MCC Stop Action
Range: Stop, Trip
Default: Stop
Defines whether MCC control trips (reset required to clear) or stops (no reset required).
Test Auto Mode
Range: On, Off, Unaffected
Default: Off
Sets whether, when the test switch is on, the auto mode is forced on, forced off, or is
unaffected.
Test Manual Mode
Range: On, Off, Unaffected
Default: On
When the test switch is on, this setpoint determines if the manual mode is forced on,
forced off, or is unaffected.
An external stop sequence has occurred if the relay detects that either contactor A or
contactor B has dropped out without receiving a stop command. If the
setpoint is programmed as "Stop", the relay will accept this as a stop control and display
the
External Stop
message. If this setpoint is set to "Trip", the relay will treat this as an
emergency stop trip. This trip condition must be reset before the motor can be restarted.
Most protection and control elements in this relay are sensitive to whether the motor is
stopped, starting, or running. These include the jam, and acceleration protection, and the
thermal start inhibit elements.
Traditionally, the motor is deemed to have entered the starting state when the motor
current changes from zero to some measurable value, and to have entered the running
state when the current having increased above FLA then subsides below FLA. This
algorithm is satisfactory for most applications. The current profile of full voltage across-
the-line starters for instance typically goes from zero to 6 × FLA within a cycle of the
contactor closing, and then decays exponentially until it reaches 1 × FLA just before
reaching normal operating speed.
MM200 MOTOR MANAGEMENT SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS
External Stop Action
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