Fluke 1630-2 FC FE 1630 Users Manual - Page 12

1630 Users Manual Using the Clamp Ground Resistance Measurements To perform ground resistance measurements: 1. Open the jaws and make sure the surfaces fit together properly and are free of dust, dirt, or any foreign substances. 2. Turn the Clamp on by moving the rotary switch to the Ω function. Note Do not attach the Clamp to a conductor or open the jaws now or during self-calibration or calibration will be interrupted. 3. After power is turned on, the Clamp self-calibrates for better accuracy. Wait for self-calibration to finish before making measurements. During the self-calibration, the display will show CAL7, CAL6,.....CAL2, CAL1. The Clamp beeps when self-calibration is completed. 4. Attach the Clamp to the electrode or ground rod to be measured. 5. Read the value of Rg (ground resistance) from the display. Figure 3 illustrates the ground resistance measurement principles. Note • If self-calibration does not stop, check the jaw surfaces for dust or dirt and power up the Clamp again. • If there is more than 3 A or 30 V in the ground rod, the jaw icon and the word NOISE flash on the display and the Clamp beeps. When noise is present the Clamp reading is not valid. • If the jaw assembly is opened during measurement, the jaw icon appears on the display. 6