CHANNEL STOCK 5P0062 - Caterpillar

Ammeter Calibration
(1) Put the 5P300 Electrical Tester in a horizontal position as shown and disconnect the power.(2) Before the start of calibration, the pointer of the AMPERES D.C. panel meter must be on the zero "0". If pointer adjustment is necessary, use a small screwdriver to turn adjustment screw (1), either clockwise or counterclockwise, to put the pointer exactly over the zero "0" on the left side of the scale.(3) Connect the 5P300 Electrical Tester POWER leads (2) to a 12 or 24 volt D.C. power supply, red to positive (+) and black to negative (-).(4) Turn AMP SELECTOR (3) to the "100" position.(5) Turn ZERO SET (4) to the center of its rotation.(6) Adjust R14 (zero adjust 100, see page 21) to get an ammeter reading of zero "0".(7) Connect a 12 volt power supply (battery or 3 amp power supply) to the 5P8608 Calibrator 12 VDC terminals (5).(8) Connect an external voltmeter (VOM) with at least 2% full scale accuracy to the VOLTMETER terminals (6) of the calibrator. Connect the coil leads to the calibrator COIL terminals (7).(9) Fasten the clamp-on ammeter pickup (8) over the calibrator coil. The arrow on the pickup must always be in the direction of current flow. Reverse the pickup position if the indication on the ammeter is not up scale.(10) Adjust CURRENT SELECTOR (9) so the ammeter will read approximately 1/3 of full scale. Press PUSH TO CALIBRATE button (10) only long enough to get an accurate reading, since heat will increase in the coil.(11) Compare ammeter reading with the voltage shown on the VOM (1 volt = 100 amps).(12) Adjust R6 (Cal. 100A) to get an ammeter reading that is 100 times the VOM reading in volts.(13) Do steps 10, 11 and 12 again at approximately 2/3 of full scale.(14) Turn AMP SELECTOR (3) to the "1000" position.(15) Adjust R15 (zero adjust 1000) to get an ammeter reading of zero "0".(16) Turn AMP SELECTOR (3) from 1000 to 100. The meter indication should be within one (1) division of zero "0".(17) Do steps 10, 11, 12 and 13 again for the "1000" position. Adjust R26 (Cal. 1000) to get an ammeter reading that is 100 times the VOM reading in volts.(18) If the ammeter is correctly adjusted, the following conditions are necessary: a) The ability to put the ammeter in the zero "0" position with ZERO SET (4) near the center of its rotation.b) The ammeter reading should always be within one (1) division of the zero "0" when the AMP SELECTOR (3) is moved between the 100 and the 1000 amp scales.c) The ammeter indication is 1 amp of the amperage reading on the calibrator voltmeter with AMP SELECTOR (3) in the "100" position and the 5P8608 Calibrator CURRENT SELECTOR (9) in the "2" position.d) The ammeter indication is 10 amps of the amperage reading on the voltmeter with AMP SELECTOR (3) in the "1000" position and the calibrator CURRENT SELECTOR (9) in the "6" position.