Use Of 6V6124 Calibration Coil{0778, 0785} Caterpillar

The 6V6124 Calibration Coil is used to check the accuracy of, and for calibration of the 6V4910 AC/DC Clamp-on Ammeter, when used with the 5P8608 or 6V6180 Calibration Group. The original 5P8609 Calibration Coil cannot be used to check the 6V4910 Ammeter, because the cross section is too large for the opening in the hand held Ammeter.

NOTE: Do not use the 6V6124 Calibration Coil for a check or calibration of the 5P969, 2P5540 Ammeters or the 5P300 Electrical Tester. The original 5P8609 Calibration Coil must be used to get accurate results on these Ammeters. The 6V6124 Calibration Coil has 300 turns of 22 gauge wire and the 5P8609 Calibration Coil has 308 turns of 20 gauge wire.

Description

See Special Instruction Form SEHS8030, "USING THE 6V4910 AC/DC CLAMP-ON AMMETER", before using the 6V6124 Calibration Coil. Read the sections on checking and calibration of the Ammeter, starting on page 11. Use that procedure, but make all of the following changes as given.

(1) The 6V6124 Calibration Coil is accurate when used in one position only. It must be held straight out from the end of the Ammeter as shown. Any change from this position will cause an error in the readings. To help keep the coil in this position during test or calibration, put the coil on the CURRENT SELECTOR switch knob, with the ammeter in the location shown.

(2) During an accuracy check, the input Voltage to the calibrator (battery or power supply Voltage) may be increased from 12 Volts to a maximum of 18 Volts at 2 Amperes. This permits the Ammeter to be checked for currents up to 600 Amperes. At high current readings, do not hold the PUSH TO CALIBRATE button down for long periods of time or the coil and calibrator will get hot. Do not use more than 18 Volts on the calibrator or do not use the calibrator to simulate (give the same indication as) currents over 600 Amperes, or the results will not be correct.

(3) When following the calibration procedure starting on page 13 of the Ammeter Special Instruction, always use 12.0 Volts in place of the 8.5 or 14 Volts given. Also, put the CURRENT SELECTOR in position 6. This will give the necessary reading of 400 (excluding the decimal points) to permit adjustment of the Ammeter calibration controls.

Repair Of The 6V6124 Calibration Coil

(1) The 6V6124 Calibration Coil can be checked with the 6V3030 Multimeter. Measure between the two leads from the coil; connect the leads directly into the V - Ohms and COM jacks on the 6V3030 Multimeter. With the FUNCTION/RANGE switch on the multimeter set at 200 Ohms (Ohms), the digital display should show approximately 6 Ohms. If the coil measures OL (infinite Ohms), it is open, and if it measures 0 Ohms, there is a short circuit.

(2) If the coil does not operate correctly it can be returned to the manufacturer for service or replacement. A letter should be sent with the unit, including a description of the problem and the date of purchase from Caterpillar Tractor Co. For units less than one year old, repair is under warranty, except for abuse. Cost of repairs on units over one year old will be charged to the owner.

Repair Service is available from: