Fluke 1630 Earth Ground Clamp Users Manual

Introduction

The Fluke 1630 Earth Ground Clamp (referred to as "the Clamp") is a hand-held, battery-operated clamp meter designed for measuring the ground resistance of a ground rod without requiring auxiliary ground rods. It is suitable for use in multi-grounded systems without needing to disconnect the ground under test.

The Clamp can be used in the following applications:

• Earth resistance testing of high voltage pylons, buildings, cell phone substations, and RF transmitters.
• Inspection of lightning protection systems.

Standard Accessories

The following standard accessories are provided with the Clamp:

• 1 x 9-V alkaline battery (type IEC 6F22, NEDA 1604 installed)
• 1 x Resistance test/check loop
• 1 x 1630 Users Manual
• 1 x Carrying Case

Contacting Fluke

To contact Fluke, please use the following telephone numbers:

• USA: 1-888-44-FLUKE
• Canada: 1-800-363-FLUKE
• Europe: +31 402-675-200
• Japan: +81-3-3434-0181
• Singapore: +65-738-5655
• Worldwide: +1-425-446-5500
• USA Service: 1-888-99-FLUKE (1-888-993-5853)

Alternatively, visit Fluke's website at www.fluke.com or register your product at register.fluke.com.

Safety Information

⚠️ Read First: Safety Information

To ensure safe operation and service of the 1630 Earth Ground Clamp, follow these instructions:

• Read the operating instructions and all safety instructions before use.
• Use the Clamp only as specified in the operating instructions; otherwise, its safety features may not provide protection.
• Adhere to local and national safety codes. Use appropriate personal protective equipment to prevent shock and arc blast injury when working near exposed hazardous live conductors.
• Before each use, inspect the Clamp for cracks, missing portions of the housing or output cable insulation, or loose/weakened components. Pay close attention to the insulation around the jaws.
• Never use the Clamp on circuits exceeding 600 V CAT II or 300 V CAT III.
• CAT II equipment is designed to protect against transients from energy-consuming equipment supplied from the fixed installation, such as TVs, PCs, portable tools, and other household appliances.
• CAT III equipment is designed to protect against transients in equipment in fixed-equipment installations, such as distribution panels, feeders and short branch circuits, and lighting systems in large buildings.
• Exercise extreme caution when working around bare conductors or busbars, as contact can cause electric shock.
• Use caution when working with voltages above 60 V dc or 30 V ac, as these pose a shock hazard.

Symbols

The following symbols are found on the Clamp or in this manual:

Getting Acquainted with the Clamp

Refer to Figures 1 and 2 and Tables 1 and 2 to become more familiar with the Clamp's features.

Figure 1. 1630 Earth Ground Clamp Features

Figure 1 shows the Fluke 1630 Earth Ground Clamp. Key components are numbered:

• 1. Jaws: Used to enclose electrode or ground wire.
• 2. HOLD button: Press to hold the displayed value.
• 3. Rotary Switch: For power on and function selection.
• 4. LCD: Liquid Crystal Display.
• 5. REC button: Press to start data logging.
• 6. Down arrow button: Used to decrement value.
• 7. Up arrow button: Used to increment value.
• 8. FUNC button: Press to select HI (high alarm), LO (low alarm), SEC (seconds), or stored memory locations.
• 9. Jaw release: Mechanism to open the clamp jaws.

Figure 2. Display Features

Figure 2 illustrates the Clamp's display features. Indicators include:

• 1. Autopower Off: Indicates the Clamp will Autopower off in 4 to 6 minutes.
• 2. Low Battery Indicator: ⚠️ Warning: To avoid false readings, which could lead to possible electric shock or personal injury, replace the batteries as soon as the battery indicator appears.
• 3. Data Logging: Indicates data logging is in progress.
• 4. Memory Location: Indicates the current memory location.
• 5. Jaw Status: Indicates the jaw is not closed properly. This symbol appears on the display.
• 6. Noise Indicator: Indicates noise present in the ground electrode or ground rod.
• 7. Alarm Function: Indicates the rotary switch is in the alarm function.
• 8. Display Value: Shows the current selected function or current memory location.
• 9. Measurement Value: Displays value from 0 to 9999 with decimal point.
• 10. Units: Indicates ohms (Ω) and alarm functions.
• 11. Units: Indicates current in mA or A.

Using the Clamp

Ground Resistance Measurements

To perform ground resistance measurements:

1. Open the jaws and ensure 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 during self-calibration, as it will be interrupted.

3. After power is turned on, the Clamp performs self-calibration for better accuracy. Wait for self-calibration to finish before making measurements. During 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 will flash on the display, and the Clamp will beep. Clamp readings are not valid when noise is present.
• If the jaw assembly is opened during measurement, the jaw icon appears on the display.

Figure 3. Ground Resistance Measurement Principles

Figure 3 illustrates the principles of ground resistance measurement. The top diagram shows the clamp around a ground rod in a multi-grounded system, with multiple ground rods (R1 to Rn) connected in parallel to the main ground rod (Rg). The lower diagrams show equivalent circuit representations, with 'Rg' representing the ground rod resistance and 'R1' through 'Rn' representing other parallel ground resistances.

Ground Leakage Current Measurement

To perform a ground leakage current measurement test:

1. Open the jaws and ensure 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 mA or A function.
3. Attach the Clamp to the electrode or ground rod to be measured. Figure 4 shows a connection for a ground leakage current measurement.
4. Read the value of the leakage current on the display.

Figure 4. Ground Leakage Current Measurement

Figure 4 shows the connection setup for a ground leakage current measurement. The clamp is shown encircling a conductor connected to a ground rod, with the clamp's jaws around the conductor.

Memory and Alarm Functions

Using the High and Low Alarms

1. Press the [FUNC] button to select the HI or LO alarm. While this example describes the ohms function, high and low alarms can be set in any of the other functions. The current value of the High or Low alarm will appear on the display. Figure 5 shows alarm function displays.
2. Press the ⬆️ or ⬇️ button to increment/decrement the value by 1 Ω. The value can be incremented or decremented from 0 Ω to 1510 Ω and then to OL. Hold down the up or down buttons to quickly increment/decrement to the desired value.
3. When the value is set, press the [FUNC] button until you return to the main display.
4. When the rotary switch is set to the ⚡ position, the Clamp compares the current value with the high and low values. If the current measurement is larger than the HI value, the Clamp beeps and shows HI-- in the upper display. If the measurement is less than the LO value, the Clamp will beep and LO-- appears in the upper display.

Figure 5. Alarm Functions

Figure 5 displays examples of the alarm functions. The top left shows a high alarm set to 100 (HI 100). The top right shows a high alarm condition (HI--). The bottom left shows a low alarm set to 10 (LO 0010). The bottom right shows a low alarm condition (LO--).

Notes on Alarms:

• If the HI value is set at OL, or the LO value is set at 0, the ALARM function will be disabled.
• The HI value cannot be smaller than the LO value, and the LO value cannot be larger than the HI value. The HI value will be adjusted to the LO value when a rollover occurs. The maximum LO value is the HI value.
• If data logging is progressing, the beeper is disabled to save battery power, but the display will still show the warning letters HI-- or LO--.
• The values of the high and low alarm are stored in memory and are restored when the Clamp is turned on.

Setting the Sampling Interval

1. Press the [FUNC] button until SEC appears in the upper display. Figure 6 shows the sampling interval display.
2. The Clamp shows the current sampling interval in seconds.
3. Press ⬆️ or ⬇️ to increment/decrement the sampling interval by 1 second. The sampling interval can be incremented or decremented from 0 to 255 seconds. Hold down the up or down buttons to quickly increment/decrement to the desired value.
4. Press the [FUNC] button until you return to the main display.

Figure 6. Setting the Sampling Interval

Figure 6 shows the display during the setting of the sampling interval, indicating "SEC" and the selected interval (e.g., 0001 second).

Logging Data

1. Press the [REC] button; REC appears in the upper display.
2. Data is recorded at the sampling interval you specified. Data logging will stop when memory is full, the Clamp detects a low battery, or you press the [REC] button again.

Note: If the sampling interval is set at 0 seconds, only one data point is recorded. To record the next data point, press the [REC] button again. The memory location is also displayed for about 1 second.

Reading Data Stored in Memory

1. Press the [FUNC] button until NO. appears on the display. The current memory location appears on the upper display, and the stored data appears on the lower display. Figure 7 shows the stored data display.
2. Press ⬆️ or ⬇️ to go to the next or previous memory location. The memory location rolls over when the first or last record is reached.

Figure 7. Stored Data Display

Figure 7 shows the stored data display. The upper part indicates the memory location (NO. 0000), and the lower part shows the stored value (e.g., 10.00 Ω).

Clearing Memory

To clear the memory, press and hold the [REC] button and then turn the Clamp on. The letters CL appear on the display, indicating that memory is cleared.

Canceling Auto-Power Off

When the Clamp is turned on, the letters AP appear on the display, indicating that Auto-Power Off is turned on. To cancel Auto-Power Off, press the [FUNC] button and then turn the Clamp on. The letters AP will no longer appear on the display.

Maintenance

⚠️ Warning: To avoid possible electric shock or personal injury, repairs or servicing not covered in this manual should be performed only by qualified personnel.

Cleaning the Clamp

⚠️ Caution: To avoid damaging the Clamp, do not use aromatic hydrocarbons or chlorinated solvents for cleaning. These solutions will react with the plastics used in the Clamp. Clean the instrument case with a damp cloth and mild detergent.

Replacing the Battery

⚠️ Warning: To avoid false readings that could lead to possible electric shock or personal injury, replace the batteries as soon as the low battery indicator (?) appears.

To replace the battery:

1. Turn the rotary switch to OFF.
2. Use a Phillips screwdriver to remove the bottom case screws.
3. Lift and remove the bottom case.
4. Remove the old battery.
5. Replace the battery with a new 9-V battery.
6. Install the bottom case and tighten the screws.

Specifications

Electrical Specifications

General Specification

Ground Loop Resistance

[1] Loop resistance with no inductance, external field < 200 A/m, external electrical field < 1 V/m, conductor centered.

Ground Leakage Current mA

Autorange 50/60 Hz, True rms, crest factor CF <3.5

Ground Leakage Current A

50/60 Hz, True rms, crest factor CF <3.5