Ac Voltage and Frequency

TB 9-4910-556-35

(11) If all indications recorded are not within limits specified, perform b below.

b. Adjustments. Perform 10b above. Repeat 10a above and adjust current probe for

in-tolerance indications on ac and dc current.

12. Ac Voltage and Frequency

a. Performance Check

(1) Connect cable W2 to J4 on VTM.

(2) Short red and black leads of cable together.

(3) Set TEST SELECT switches to 93.

(4) Press and hold TEST pushbutton until CAL appears on VTM. Release TEST

pushbutton.

(5) Wait for offset value to appear on display. Offset value will be between +6.8 and

-6.8.

(6) Connect equipment as shown in figure 4.

Figure 4. Ac voltage and frequency - equipment setup.

(7) Adjust synthesizer/function generator for 400 Hz indication and a 5.0 V rms

indication on digital multimeter.

(8) Press and release TEST pushbutton on VTM.

VTM display will indicate

between +4.6 and +5.4.

CAUTION

Do not exceed 35 V ac input to VTM when checking frequency.

(9) Set TEST SELECT switches to 96.

(10) Set synthesizer/function generator for 500 Hz square wave.