MPU-16A / FPU-16 TEST UNIT TUTORIAL

TU-16 TEST UNIT

TU-16 INITIAL SETTINGS PROGRAM CHANGE: Disable ANALOG OR DUAL / RS-485 OUTPUT: Analog or Dual output UNBALANCE: Adjust counter-clockwise to minimum SENSOR SELECT: Select RTD or PTC to match MPU-16A PHASE / EARTH LEAKAGE CURRENT: Off RTD / PTC RESISTANCE: CURRENT: UNIT POWER: Off MAIN POWER: On PROGRAM CHANGE: Disable

MPU-16A FACE PLATE & OPERATOR INTERFACE TRIP/ALARM, Red LED On: Trip or alarm Flashing: Program-change lockout defeated PROCESSOR, Green LED Indicator On: Processor functional RAMP switch: Adjusts value digits MODE switch: Selects modes “0” through “F” RESET switch: Resets trips and alarms ENTER switch: Enters values, accesses alarm set points and values at trip LIQUID CRYSTAL DISPLAY MODE digit: Identifies mode VALUE digits: Display set points, trip-and-alarm codes, and meter readings MEMBRANE SWITCH KEYPAD MODE LIST The faceplate of the MPU consists of 4 sealed bubble buttons for programming, a liquid-crystal display, two LED’s for indication, and Mode lists. The first digit of the display is the mode indication. There are set-point modes that store the programmable trip and alarm set points, and to store motor data. These include I2t Limit (s @ 600%FLA), Overcurrent (%), Undercurrent (%), Current Unbalance (%), Temperature (deg. C), Earth Fault (%), Full-Load Current (A), and motor Service Factor (%) , and CT Primary Ratings (A). There are also status modes that enable you to view Ammeter (A)(%), Peak Current (A), Current Unbalance (%), Temperature (deg C), Earth Leakage (A), and percent I2t. The value displayed is the value of the set-point or reading in the designated unit. If the Enter button is pressed the LCD will display the alarm set points while in set-point mode or the last trip value while in a status mode. The Ramp and Mode buttons are used to scroll through set point values and to select the appropriate mode for viewing. To change scrolling direction release the button and re-press within one second. The red LED indicates a trip-or-Alarm if on constantly and indicates that programming is enabled active when it is flashing. The green LED indicates that the MPU-16A microprocessor is functioning properly.

MPU-16A DEFAULT VALUES The Program Enable/Disable Lockout Key must be in the enable position. Consult the MPU-16A manual or TU-16 handout for default values. To set the MPU-16A factory default values, cycle the unit’s power while pressing the reset button.

*These values are derived from the motor specifications. MPU-16A INITIAL SETUP The MPU-16A is initially set up by entering the following values*: Mode F: CT Primary Ratings (A) Mode 0: I2t Thermal Limit (s) Mode 6: Full Load Current (A) Mode 7: Service Factor (%) *These values are derived from the motor specifications.

MPU-16A SETUP Enter the desired value for the following set-points on the MPU-16A: Mode 1: Overcurrent Mode 2: Undercurrent Mode 3: Current Unbalance Mode 4: Temperature Mode 5: Ground Fault

MPU-16A PROGRAMMABLE SELECTIONS - Mode 8 Phase reverse Phase sequence Earth-fault delay time Hot-motor compensation Short-circuit trip Latching alarms Autoreset on thermal trip Operating mode of output relays Isolated analog-output parameter To enter the programmable selections in Mode 8, please refer to the Mode 8 Table in the MPU-16A manual or in the TU-16 handout.

MPU-16A PROGRAM - MODE 8 VALUE DIGIT 3 1 2 3 4 5 6 7 8 9 A B C D E F 1 2 3 4 5 6 7 8 9 A B C D E F HOT-MOTOR COMP 0=Off 1=On SHORT-CIRCUIT TRIP ALARM-LATCH AUTORESET (MODE 0)

MODE 8 - SECOND LEVEL WITHOUT COMMUNICATIONS

MODE 8 - SECOND LEVEL WITH COMMUNICATIONS

MPU-16A METERING MODES Mode 9: Ammeter (A) or (%) —Meter values-at-last-trip Mode A: Peak current (A) —Percent current modulation Mode B: Current unbalance (%) —Meter values-at-last-trip Mode C: Temperature (°C) —Meter values-at-last-trip Mode D: Earth leakage (A) —Meter values-at-last-trip Mode E: Percent I2t —Minutes to reset

EMERGENCY THERMAL RESET - Mode E Mode E: Displays %I2t when running or stopped. Displays time to reset when tripped in Mode 0, and <reset> is pressed ACTIVITY: Trip the unit on I2t and perform an emergency thermal reset. Used I2t reduced to 0%. Thermal overload is reset. RTD trip is temporarily disabled. Occasionally it is desired or required to restart a motor, that has tripped on thermal capacity, before the used thermal capacity reduces to 30%, the point at which a normal Mode 0 reset may be accomplished. The motor protection unit’s thermal model is reset to zero and temperature protection is temporarily disabled by performing an “Emergency Thermal Reset”. Select Mode E, enable programming, press Reset and Enter simultaneously. NOTE: The main purpose of having a special emergency thermal reset is to force the user to make a conscious decision to restart the motor.

MPU-16A WORKED EXAMPLE 4160 V HP: 2500 HP sf: 1.15 FLA: 359 A LR: 735% LR time: 20s Overload Class: 30 ACTIVITY: We are going to program the MPU-16A to protect this motor. The proper CT-primary ratings and set-point values will be calculated from the given motor data, and then entered in the appropriate modes of the MPU-16A.

MPU-16A WORKED EXAMPLE 4160 V HP: 2500 HP sf: 1.15 FLA: 359 A LR: 735% LR time: 20s Overload Class: 30 SOLUTION Phase CT’s should be selected so that the motor FLA is approx. 70% of the primary rating. In this case, use a primary rating of 500-A. Program this value in Mode F. Calculate an acceptable phase-CT-primary rating for use with the MPU-16A for this application.

MPU-16A WORKED EXAMPLE 4160 V HP: 2500 HP sf: 1.15 FLA: 359 A LR: 735% LR time: 20s Overload Class: 30 SOLUTION The Overload Class can be calculated using the I2t formula and the locked rotor data. In this case, we are given an Overload Class of 30. Program this value in Mode 0. Calculate the thermal overload time and enter this value in Mode 0.

MPU-16A WORKED EXAMPLE 4160 V HP: 2500 HP sf: 1.15 FLA: 359 A LR: 735% LR time: 20s Overload Class: 30 Enter the motor Full-Load Current (FLA) in Mode 6. Enter the Service Factor (sf) in Mode 7. The MPU-16A is now ready for use.

MPU-16A WORKED EXAMPLE 4160 V HP: 2500 HP sf: 1.15 FLA: 359 A LR: 735% LR time: 20s Overload Class: 30 Change the program (Mode 8) to have the following characteristics: Phase Rotation: bac Phase Reverse: enabled Earth-Fault Delay: instantaneous Hot-Motor Compensation: off Short Circuit Trip: on Alarm Latch: off Auto Reset: off SOLUTION To program Mode 8, refer to Table in the MPU-16A manual or in the TU-16 handout.

MPU-16A PROGRAM - MODE 8 VALUE DIGIT 3 Phase Rotation: bac 1 2 3 4 5 6 7 8 9 A B C D E F HOT-MOTOR COMP 0=Off 1=On SHORT-CIRCUIT TRIP ALARM-LATCH AUTORESET (MODE 0) Phase Rotation: bac Phase Reverse: enabled Earth-Fault Delay: instantaneous Hot-Motor Compensation: off Short Circuit Trip: on Alarm Latch: off Auto Reset: off