CHAPTER 5: SETPOINTS
PROTECTION ELEMENTS
MM300 MOTOR MANAGEMENT SYSTEM – INSTRUCTION MANUAL
5–49
Current Unbalance Alarm Delay
Range: 1 to 60 seconds in steps of 1
Default: 1 second
This setpoint specifies the time the motor unbalance current must meet or exceed
pickup to generate an alarm.
Phase undervoltage
An undervoltage on a running motor with a constant load results in increased current. The
relay thermal model typically picks up this condition and provides adequate protection.
However, the phase undervoltage element may be used to provide for an advance warning
alarm and/or for tripping before the motor has heated.
In some motor manager relays, the undervoltage feature is used for additional conditions.
Instead, the MM300 uses the undervoltage restart element to handle loss of supply, and
the fuse fail element to cover main and VT fuse failure.
The element generates alarms or trips when any of the three phase-to-phase voltages
meets or falls below the pickup level.
NOTE
NOTE:
Phase undervoltage protection is available only when a type B option card (3 × VT) is
included in the order code.
The following setpoints are available.
Undervoltage Alarm Level
Range: 60 to 99% of MNV in steps of 1, or OFF
Default: OFF
This setpoint specifies the phase undervoltage alarm pickup level as a percentage of the
rated voltage.
Undervoltage Alarm Delay
Range: 1 to 60 seconds in steps of 1second
Default: 30 seconds
This setpoint specifies the time that the voltage must be less than or equal to, the
undervoltage alarm pickup level to generate an alarm.
Undervoltage Trip Level
Range: 60 to 99% of MNV in steps of 1, or OFF
Default: OFF
This setpoint specifies the phase undervoltage trip pickup level as a percentage of the
rated voltage.
Undervoltage Trip Delay
Range: 1 to 60 seconds in steps of 1 second
Default: 30 seconds
This setpoint specifies the time that the voltage must be less than or equal to, the
undervoltage trip level to generate a trip.
Undervoltage Min Level
Range: 5 to 39% of MNV in steps of 1, or OFF
Default: OFF
This setpoint specifies the phase undervoltage minimum level as a percentage of the
rated voltage. The OFF setting enables the Undervoltage function to detect the
undervoltage condition at zero voltage The “Phase UV Min Level” message will be
generated if the voltage is lower than the Undervoltage Alarm Level threshold.
NOTE
NOTE:
This protection function can be bypassed while the device is in Test Mode. The feature is
available by setting the setpoint 'PRT Func Ignore in Test Mode' to Enabled.
Summary of Contents for Multilin MM300
Page 20: ...1 14 MM300 MOTOR MANAGEMENT SYSTEM INSTRUCTION MANUAL SPECIFICATIONS CHAPTER 1 INTRODUCTION ...
Page 184: ...6 8 MM300 MOTOR MANAGEMENT SYSTEM INSTRUCTION MANUAL COMMANDS CHAPTER 6 DIAGNOSTICS ...
Page 198: ...A 6 MM300 MOTOR MANAGEMENT SYSTEM INSTRUCTION MANUAL REPAIRS CHAPTER A APPENDIX A ...