PARALLEL OPERATION (LOAD TRANSFER).

ARMY TM 9-6115-464-12 AIR FORCE TO 35C2-3-445-1 NAVY NAVFAC P-8-624-12 2-11 PARALLEL OPERATION (LOAD TRANSFER). The following method of parallel operation is to be used when it is necessary to transfer the load from one set to the other without interrupting power. a. b. c. d. e. f. g. h. i. j. k. l. 2-20 NOTE Visually check that the power cable and parallel cabel are in accordance with Figure 2-6. If the cables are not attached as indicated, shutdown the “on-line” set and follow instructions in paragraph 2-9. Do not attempt load connects in paragraph 2-9 unless all sets are off and no other external voltage is applied to the load. Equipment damage could result if caution is not observed. The set in operation shall be designated as “on-line” and the sets placed in parallel operation shall be designated “on-coming”. Place the operations switch (26, Figure 2-1 ) on both sets in the PARALLEL OPERATION position. Do not close the circuit breaker switch after starting the “on-coming” set as serious damage to one or both generator sets may result. Equipment dam- age could result if caution is not observed. Refer to paragraph 2-6 and start the “on-coming” set. Do not perform steps 7 & 8 of Figure 2-8. Note the voltage indicated on the “on-line” set. Adjust the voltage of the “on-coming” set to the voltage noted on the “on-line” set. Adjust the frequency of the “on-coming” set to a higher value than that of the “on-line” set. Slowly reduce the frequency of the “on-coming” set until the SYNCHRONIZING LIGHTS (25, Figure 2-1) flash at 2 to 3 second intervals. Do not place the circuit breaker switch of the “on-coming” set in the CLOSE position while the SYNCHRONIZING LIGHTS are lit as damage to one or both generator sets may result. Equipment damage could result if caution is not observed. Carefully watch the SYNCHRONIZING LIGHTS of the “on-coming” set. At the instant both lights go dark, move the circuit breaker switch of the “on-coming” set to the CLOSE position. Adjust the voltage and frequency rheostats of the “on-coming” set until load and current are divided equal- ly between the two generator sets. Move the circuit breaker switch (30) of the “on-line” set to the OPEN position. Place the operations switch of the “on-coming” set to the SINGLE UNIT OPERATION position. Readjust voltage and frequency of the “on-coming” set as necessary. Refer to paragraph 2-7 and stop the “on-line” set.