Adjustments.

TB 55-4920-346-34

(3) Position the test instrument controls as follows:

(a) METER switch to INTERNAL.

(b) METER MODE to AC VOLTS-VAR 0

(4) Turn on signal generator (Al) power, allow proper warm-up. Adjust FREQ control for 400 Hz and OUTPUT

control for 110 vac + 0.2 volts as indicated on voltmeter (A2).

5) Depress and hold the CALIBRATE pushbutton on the test instrument.

(6) Test instrument meter must indicate LEAD 180. If not, perform b(1) below.

(7) Decrease OUTPUT of signal generator to zero and disconnect jumper wire from R7 and terminal E15.

(8) Adjust signal generator OUTPUT to 110 vac + 0.2 volts as indicated on voltmeter.

(9) Depress and hold the CALIBRATE pushbutton on the test instrument. The test instrument meter will indicate

in the center of the RED area on the scale. If not, perform b(2) below.

(10) Release CALIBRATE pushbutton. Test instrument will indicate 110 + 2.0 volts. Set METER MODE

selector to AC VOLTS-REF 0 and observe that the test instrument meter reads the same voltage. If not, perform b(3)

below.

(11) Disconnect equipment from the test instrument.

(12) Connect 115 vac, 400 Hz input power to TI, as shown in figure 4, using signal generator (A1).

(13) Connect a 2-phase power source as shown in figure 4.

(14) Set METER MODE selector on the test instrument to PHASE ANGLE.

(15) Set 115 vac POWER switch to ON.

(16) Test instrument meter pointer deflects to LAG side of zero. (Note location of meter pointer.)

(17) Set all power to OFF and reverse the connections to test points 16 and 17.

(18) Set all power to ON. Test instrument meter pointer deflects to LEAD side of zero. (Note location of meter

pointer.)

(19) The reading in steps (16) and (18) above will be equal in Phase Angle, one leading and one lagging. If not,

perform b(4).

(20) Set all power to OFF and remove all test and power connections.

b. Adjustments.

(1) Adjust potentiometer R6 for an indication of 180.

(2) Adjust potentiometer R7 for red center area on the scale.

(3) Adjust potentiometer R4 for an average reading between the two METER MODE SELECTOR settings AC

VOLTS-REF 0 and AC VOLTS-VAR 0.

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