scr_5000.sam-01/93 Page 6 Motor Field Adjustments

C. Motor Field Adjustments

1. Turn off the main line disconnect to remove power to the Manetek Drive and to the motor fields.
2. Wait at 10 seconds for the field current to decay and remove one of the motor field leads either MF+ or MF-.
3.Measure the resistance of the motor fields. It should be the same as indicated on the Motor Field Schematic. If the resistance is different, the motor fields will have to be connected in either series or series parallel.
4. After all necessary reconnections have been made to the motor fields, turn on the main line disconnect.
5. Set voltmeter for DC voltage and place the positive lead on MF+ and the negative lead on MF- terminals.
6. On the Field Regulator Board (2EA) close switches 2SS and 3SS. Close 1SS if the rated hoist motor armature voltage is above 250VDC. If it is below 250VDC, keep 1SS open.
7. Adjust the Max Field Current (3RH) pot on the Field Regulator Board (2EA) so that the voltage at MF+ to MF- matches the Run voltage indicated on the Motor Field Schematic.
8. Open 3SS and adjust the Field Economy (5RH) pot on the Field Regulator Board (2EA) so that the voltage at MF+ to MF- matches the STANDBY voltage indicated on Motor Field Schematic.
9. Close 3SS switch. The motor field volts should increase up to Run voltage value. If the increase from STANDBY to RUN occurs at a slow rate, adjust the RESPONSE (4RH)pot to compensate.
10. Adjust the CROSSOVER POINT (2RH) pot all the way clockwise.
11. with the voltmeter on the DC scale, measure test points 1TP to 3TP on the Field Current Monitor board(place the positive lead on 1TP). Adjust the CALIBRATION (2RH) pot to get -1.0V with full field voltage.
12. Open the 3SS switch on the Field Regulator Board (2EA)to get STANDBY voltage. Adjust the TRIP LEVEL (1RH) pot on the Field Current Monitor board until the Field Loss led comes on. Readjust the TRIP LEVEL pot backwards until the LED goes off.
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