Eaton MP-3000 Motor Protection Relay Guide

After thermal overload tripping, it is necessary to wait for the hot bucket to cool down to below the I ² t alarm threshold before resetting.

4.5 RTD enhanced protection

When connecting the URTD module and motor winding RTD, the protection performance of MP-3000 is significantly improved:

Direct temperature measurement: comparison of winding temperature with user set alarm/trip temperature values

Adaptive thermal model: The thermal model combines measured temperature, effective heating current, and motor constant to more accurately simulate the effect of temperature on cooling (the higher the temperature, the faster the heat dissipation)

When using RTD, even if the effective current is higher than UTC, the relay may remain tripped based on the winding temperature report. This greatly improves the load capacity of the motor, especially at normal ambient temperatures.

Important reminder: Many users mistakenly believe that connecting RTDs will make protection more conservative and easier to trip. The fact is quite the opposite - using RTD significantly improves the load capacity of the motor.

4.6 Example of Protection Curve

MP-3000 automatically calculates the protection curve based on the set motor parameters. Typical parameter examples:

FLA: 100% (benchmark)

LRC: 610% (6.1 times FLA)

LRT: 15 seconds (cold start)

UTC: 100% (service factor 1.0)

IOC: 1200% (12 times FLA)

Under load trip: 60% FLA, 5-second operation delay

Blocked rotor trip: 180% FLA, 5-second operation delay

Chapter 5 Detailed Explanation of Parameter Settings

5.1 Parameter organization method

The parameters of MP-3000 are organized by page, with each page containing multiple lines of settings. Set the number as PnLm, where n is the page number and m is the line number.

To enter programming mode, open the front panel protective door and press the Program button. Parameter modifications will not take effect immediately until the Program button is pressed again to exit programming mode, at which point all modifications will take effect simultaneously.

5.2 Motor constant setting (Page 1)

Setting Description Scope Description

P1L1 FLA full load current 10-3000 A motor nameplate value, non adjustable

P1L2 LRC stalling current 300-1200% FLA motor stalling current percentage

P1L3 LRT stalling time 1-120 seconds allowed stalling time during cold start

P1L4 UTC final trip current 85-150% FLA is usually set as service factor x 100%

P1L5 PCT phase CT ratio of 10-4000 CT ratio molecules

P1L6 GCT Ground CT Ratio 10-4000 Ground CT Ratio Molecular

P1L7 FREQ frequency 50/60 Hz power supply frequency

P1L8 REV/NONREV reversible/irreversible - Is motor reversal allowed

P1L9 STOP stop current threshold 2-20% PCT determines the current level at which the motor stops

Important constraint: FLA/PCT must be between 0.25 and 1.5, otherwise it cannot exit programming mode.

5.3 RTD Settings (Page 2)

Setting Description Scope Description

P2L2 WD T winding temperature trip 0-199 ° C, OFF maximum winding temperature trip value

P2L3 WD A winding temperature alarm 0-199 ° C, OFF winding temperature alarm value

P2L4 MB T motor bearing trip 0-199 ° C, OFF motor bearing temperature trip value

P2L5 MB A motor bearing alarm 0-199 ° C, OFF motor bearing temperature alarm value

P2L6 LB T load bearing trips 0-199 ° C, OFF load bearing temperature trip value

P2L7 LB A load bearing alarm 0-199 ° C, OFF load bearing temperature alarm value

P2L10 DIAG RTD diagnosis ON/OFF RTD fault alarm enabled/disabled

Note: The URTD module has 11 input channels, with the first 6 dedicated to motor windings, channels 7-8 for motor bearings, channels 9-10 for load bearings, and channel 11 for auxiliary inputs.

5.4 Trip Setting (Page 3)

Setting Description Scope Description

P3L1 GFT ground fault tripping 2-55% GCT, OFF ground fault tripping level

P3L2 GFSD ground fault startup delay 2-60 cycles. Ground fault protection activation delay after startup

P3L3 GFRD grounding fault operation delay 0-60 cycles grounding fault holding time

P3L4 IOC instantaneous overcurrent trip 300-1600% FLA, OFF high current fault trip level

P3L5 IOCSD IOC startup delay 2-60 cycles IOC protection activation delay after startup

P3L6 JMT stalling trip 100-1200% FLA, OFF mechanical stalling trip level

P3L7 JMSD stall start delay 0-1200 seconds, stall protection activation delay after startup

P3L8 JMTR stall operation delay 0-240 seconds stall state retention time

P3L9 ULT underload trip 6-90% FLA, OFF load loss trip level

P3L10 ULSD underload start delay 0-120 seconds, underload protection activation delay after startup

P3L11 ULTRA underload operation delay 0-240 seconds underload state retention time

P3L12 UBT phase unbalanced trip 4-40%, OFF phase unbalanced trip level

P3L13 UBSD Unbalanced Start Delay 0-120 seconds Unbalanced Protection Enable Delay After Start

P3L14 UBTR unbalanced operation delay 0-240 seconds unbalanced state maintenance time

5.5 Alarm Settings (Page 4)

Setting Description Scope Description

P4L1 GFA ground fault alarm 2-55% GCT, OFF ground fault alarm level

P4L2 I2TA I ² t alarm 60-99%, OFF thermal accumulator filling percentage alarm

P4L3 JMA stalling alarm 100-1200% FLA, OFF mechanical stalling alarm level