Amprobe GP-2A Operating Manual

GP-2 GeoTest

Instruction Manual

EN - 1

GP-2 GeoTest

1. PRECAUTIONS AND SAFETY MEASURES.....................................................................3

1.1. PRELIMINARY INSTRUCTIONS ........................................................................................3

1.2. DURING USE......................................................................................................................4

1.3. AFTER USE.........................................................................................................................4

2. GENERAL DESCRIPTION.....................................................................................................5

2.1. INSTRUMENT DESCRIPTION...........................................................................................6

3. PREPARING THE INSTRUMENT........................................................................................8

3.1. INITIAL CHECK...................................................................................................................8

3.2. POWER SUPPLY................................................................................................................8

3.3. CALIBRATION.....................................................................................................................8

3.4. STORAGE...........................................................................................................................8

4. SWITCH FUNCTIONS............................................................................................................9

4.1. EARTH 2 WIRES.................................................................................................................9

4.2. EARTH 3 WIRES...............................................................................................................12

4.3. "ρ" MODE (Resistivity of the Earth)...................................................................................15

4.3.1. SELECTING THE UNITS OF MEASURE.........................................................................15

4.3.2. OPERATING INSTRUCTIONS....................................................................................15

4.4. ANOMALOUS SITUATIONS WHICH CAN OCCUR DURING TESTS............................19

5. HOW TO SAVE, RECALL AND CANCEL DATA.............................................................22

5.1. TO SAVE: "SAVE" KEY.....................................................................................................22

5.2. TO RECALL: "RCL" KEY...................................................................................................23

5.3. TO CANCEL: "CLR" KEY..................................................................................................24

6. RESET AND DEFAULT PARAMETERS...........................................................................26

6.1. HARD RESET...................................................................................................................26

6.2. DEFAULT PARAMETERS................................................................................................26

6.2.1. DEFAULT PARAMETERS..........................................................................................26

7. CONNECTING THE INSTRUMENT TO A PC..................................................................27

8. MAINTENANCE.....................................................................................................................28

8.1. GENERAL..........................................................................................................................28

8.2. BATTERY REPLACEMENT..............................................................................................28

8.3. CLEANING.........................................................................................................................28

9. TECHNICAL SPECIFICATIONS.........................................................................................29

9.1. TECHNICAL FEATURES..................................................................................................29

GENERAL FEATURES................................................................................................................31

9.2. OPERATING CONDITIONS..............................................................................................32

9.2.1. ENVIRONMENTAL CONDITIONS ................................................................................32

9.2.2. EMC..................................................................................................................32

9.3. ACCESSORIES.................................................................................................................32

9.3.1. STANDARD AND OPTIONAL ACCESSORIES..................................................................32

10. SERVICE.................................................................................................................................33

10.1. WARRANTY......................................................................................................................33

10.2. SERVICE...........................................................................................................................33

11. PRACTICAL REPORTS FOR ELECTRICAL TESTS......................................................35

11.1. EARTH RESISTANCE MEASUREMENT .........................................................................35

11.2. EARTH RESISTIVITY MEASUREMENT ..........................................................................38

EN - 2

GP-2 GeoTest

Warning: Should you fail to keep to the prescribed instructions you could

1. PRECAUTIONS AND SAFETY MEASURES

This instrument complies with European Community (EC) standards: EN61557-1, EN61557-5 and EN 61010-1.

WARNING: For your safety as well as that of the instrument you are

recommended to follow the procedures described in this instruction manual and carefully read all the notes preceded by

the symbol .

Before and during measurements please carefully heed the instructions below:

F Do not measure in wet or dusty places; F Do not measure in the presence of gas, explosive materials or combustibles; F Do not touch the circuit under test if no measurement is being taken; F Do not touch exposed metal parts, unused terminals, circuits, etc… F Do not use the instrument if it seems to be malfunctioning (i.e. if you notice

deformations, breaks, leakage of substances, absence of messages on the display etc…);

F Be particularly careful when measuring voltages higher than 25V in potentially

hazardous areas (such as building sites, swimming pools and so on) and higher than 50V in any area, in order to avoid the risk of electrical shocks.

The following symbols are used in this manual:

damage the instrument and/or its components or endanger your personal safety.

Switch

1.1. PRELIMINARY INSTRUCTIONS

F This instrument has been designed for use in environments with pollution rating 2.

It can be used for tests on installations of excess voltage category III max 250V (phase to earth).

F Always keep to the usual safety standards intended to:

- protect you against dangerous currents;

- protect the instrument against incorrect operation.

F Only the accessories supplied with the instrument guarantee compliance with the

safety standards. Accordingly, they must be used only when in good condition and, if necessary, they must be replaced with identical factory parts.

EN - 3

GP-2 GeoTest

F Use the instrument in TT, TN, IT system and industrial, civil, medical electrical plants,

in normal conditions (contact voltage limit 25V) and in particular condition (contact voltage limit 50V).

F Do not take measurements on circuits exceeding the specified current and voltage

limits.

F Do not take measurements under conditions exceeding the limits stated in paragraphs

9.2.1 and 9.2.2.

F Make sure that the batteries are properly installed. F BEFORE connecting the alligator clips to the circuit under test, make sure that the

switch is in the correct position.

F Make sure that the display shows the same function as that to which the switch is set.

1.2. DURING USE

Please read carefully:

WARNING: Should you fail to keep to the prescribed instructions you could

damage the instrument and/or its components or endanger your personal safety.

F Before setting, or changing, the switch position, disconnect the alligator clips from the

circuit under test.

F When the instrument is connected to the circuit under test, do not touch any unused

terminal(s).

F Do not take resistance measurements in the presence of external voltages; even if the

instrument is protected, any excessive voltage may cause unit malfunction.

WARNING: If, during use, the symbol appears, suspend the test and

replace the batteries (see paragraph 8.2). The instrument is able to keep in memory any previously saved data for approximately 10 minutes.

1.3. AFTER USE

F After use, move the switch to the OFF position. F If you do not expect to use the instrument for more than 30 days, remove the batteries.

EN - 4

GP-2 GeoTest

2. GENERAL DESCRIPTION

Thank you for purchasing a quality AMPROBE Test Instrument. This instrument will provide you with accurate and reliable measurements provided that it is used according to this manual’s instructions

The GP-2 GeoTest is able to measure:

F EARTH 2 WIRES: 2 wires earth resistance F EARTH 3 WIRES: 3 wires earth resistance

F ρρ: 4 wires earth resistivity

The GP-2 GeoTest uses the "Fall of potential" method of measurement for all of the above tests.

EN - 5

2.1. INSTRUMENT DESCRIPTION

ESC

DISP

SAVE

CLR

Rotary switch:

GP-2 GeoTest

DIST

AVG

Permits selection of the desired function

OFF

RCL

Figure 1: Front panel

EN - 6

GP-2 GeoTest

AVG

ESC

SAVE

DIST

RCL

DISP

CLR

F Displays the average value of the earth resistivity, calculated on the

basis of all valid measurements taken.

F Selects the distance "D" between the earth rods (ρ resistivity test).

F Increases the value of the parameter D; Scrolls through the recorded

test results; or Selects the unit m/ft.

F Decreases the value of the parameter D; Scrolls through the recorded

test results; or Selects the unit m/ft.

F Starts a measurement.

F Escape from (exit) the selected function or mode.

F Saves test results.

F Recall recorded test results.

F Displays recorded data from the selected memory location.

F Deletes:

- the average value of the measurements and the number of the tests included in the average value calculations

- recorded test results from a specified memory location

EN - 7

GP-2 GeoTest

3. PREPARING THE INSTRUMENT

3.1. INITIAL CHECK

This instrument has been carefully checked for proper electrical and mechanical function prior to shipment. All possible precautions have been taken in order to deliver it in the best possible condition.

Nevertheless, on receipt of the instrument we suggest that it be checked completely to make sure that no damage has occurred in transit. Should you find anomalies please contact the carrier immediately.

Please also make sure that the package contains all the accessories and parts listed in paragraph 9.3.1. In case of discrepancies please contact your dealer.

Should it be necessary to return the instrument, please refer to the instructions in paragraph 10.

3.2. POWER SUPPLY

The instrument is powered by 6 size 'AA' 1.5V batteries ( LR6– AM3 – MN 1500) not included in the package.

For correct installation of the batteries see paragraph 8.2. When the batteries are low the symbol appears. For replacement see paragraph 8.2.

3.3. CALIBRATION

The instrument complies with the standards mentioned in this manual. Its performance is guaranteed for one year from the date of purchase.

3.4. STORAGE

To guarantee accurate measurements, after extended storage in severe environmental conditions please allow the unit to normalize to proper ambient conditions.(see environmental conditions listed at paragraph 9.2.1).

EN - 8

GP-2 GeoTest

Secondary display on the

4. SWITCH FUNCTIONS

4.1. EARTH 2 WIRES

Whenever it is not possible to drive rods into the ground to take a 3-wire measurement, or in case of TT installations it is possible to use the simplified 2-wire method (Figure 2) which gives an excess (therefore safer) value. To carry out the test a suitable auxiliary rod is necessary; a rod is “suitable” when its earth resistance is negligible and it is independent of the earth equipment under test. In Figure 2 a water pipe has been used as auxiliary rod. However, any metal body driven into the ground can be used, provided that the above said requirements are met. Although this test is not provided for by the CEI 64.8 standard at present, it gives a value, which many 3-wire comparison tests have proved to be revealing for earth resistance.

ESE S

Figure 2: 2 wire earth resistance measurement

Measuring procedure:

F Insert the 4 connectors (black, red, blue and green) of the measuring cables into the

corresponding input terminals of the instrument (E, S, H, ES).

F Connect the alligator clips as shown in Figure 2. F Position the switch on EARTH 2 WIRES.

Display appearance:

Main display

Secondary display on the lefthand side:

In this stage it displays the eventual interfering voltage present on the circuit

------

right-hand side

0 0 V - - -- - -

EN - 9

GP-2 GeoTest

Average value of the resistance calculated Value of the

resistance

Press GO to take the measurement and read the result on the display. At the end of the test, a screen similar to the following will be displayed.

NOTE! If you keep pressing GO, the instrument takes more measurements

consecutively. When a new value is acquired, the symbol Ω blinks on the main display, the instrument emits a short sound and the counter shown on the

secondary display on the left-hand side is updated. This counter indicates the number of measurements calculated on the basis of the average resistance value.

No. of earth resistance measurements

included in the calculation of the average resistance

0.960.96 ΩΩ

2 2 0.93 0.93 ΩΩ

as:

(Val1+Val2+…+Valn)/(No. measurements)

WARNING: When the message “Measuring” appears on the display, the

instrument is measuring. Do not disconnect the alligator

clips during the measurement.

Ex.: if the operator takes three measurements consecutively, the instrument will

display:

- 1st measurement: main display = measured resistance value (Ex: 0.90Ω)

secondary display on the left-hand side = 001 (no. of measurements = 1 means that 1 earth measurement has been taken) secondary display on the right-hand side = average of the measurements taken (in case just one measurement has been taken the average value is equal to the measured value, in this case 0.90Ω)

- 2nd measurement: main display = measured resistance value (Ex: 0.96Ω)

secondary display on the left-hand side = 002 (no. of measurements = 2 means that 2 earth measurements have been taken consecutively) secondary display on the right-hand side = average of the measurements taken ((Val1+Val2)/no. of measurements = (0.90+0.96)/2 = 0.93Ω)

- 3rd measurement: main display = measured resistance value (Ex: 0.93Ω)

EN - 10

GP-2 GeoTest

SAVE

CLR

secondary display on the left-hand side = 003 (no. of measurements = 3 means that 3 earth measurements have been taken consecutively) secondary display on the right-hand side = average of the measurements taken ((Val1+Val2)/no. of measurements = (0.90+0.96+0.93)/3 = 0.93Ω)

NOTE! A test with a result over 700Ω is not inserted in the calculation of average value.

Example:

1st measurement Main display: 1,07Ω

Secondary display on the left-hand side: 1 Secondary display on the right-hand side: 1,07Ω

2nd measurement Main display: 4,15Ω

Secondary display on the left-hand side: 2 Secondary display on the right-hand side: 2,61Ω

3rd measurement (not inserted in the average value)

Main display: 1018Ω Secondary display on the left-hand side: 2

Secondary display on the right-hand side: 2,61Ω

Press CLR if you want to cancel the average value of the resistance and the no. of measurements which are included in the calculation (displayed on the secondary displays on the right-hand side and on the left-hand side respectively). A screen similar to the following will be displayed:

Last value of resistance measured

0.960.96 ΩΩ

- - - - - - - - -- - -

The test results can be stored in memory by pressing SAVE (see paragraph

5.1).

NOTE! The resistance measurement is taken according to a 4-wire voltmetric method.

Therefore, it is not affected by the resistance value of the cables used: it is not necessary to calibrate the cables or their extension.

EN - 11

GP-2 GeoTest

Secondary display on the left-

Secondary display on the

4.2. EARTH 3 WIRES

The measurement is taken according to what is prescribed for CEI 64.8, IEC 781, VDE 0413, EN61557-5 standards.

Small earth plant:

- current probe (terminal H, blue wire) positioned a distance from the earth equipment outline

CAT III 440 V P-N-PE 250 V

ESES

corresponding to five times the diagonal of the area of the earth equipment.

Large earth plant:

- current probe (terminal H, blue wire) positioned a distance from the earth equipment outline corresponding the diagonal of the area of the earth equipment.

Figure 3: 3 wires earth resistance measurement

Measuring procedure:

F Insert the 4 connectors (black, red, blue and green) of the cables into the

corresponding input terminals of the instrument (E, S, H, ES).

F Connect the alligator clips as shown in Figure 3. F Position the switch to EARTH 3 WIRES.

Display appearance:

Main display

hand side:

In this mode it displays the eventual interfering voltage present on the circuit

------

right-hand side

0 0 V - - -- - -

Press GO to take the measurement and read the value on the display. At the end of the test, a screen similar to the one below will be displayed.

NOTE! If you keep pressing GO, the instrument takes more measurements

consecutively. When a new value is displayed, the symbol Ω blinks on the main display, the instrument emits a short sound and the counter shown on the

EN - 12

secondary display on the left-hand side is updated. This counter indicates the

No. of earth resistance

Average value of the resistance calculated Value of the resistance

quantity of measurements included in the calculation of the average resistance value.

measurements included in the calculation of the average resistance

WARNING: When the message “Measuring” appears on the display, the

instrument is measuring. Do not disconnect the alligator

clips during the measurement.

GP-2 GeoTest

measured

0.960.96 ΩΩ

2 2 0.93 0.93 ΩΩ

as:

(Val1+Val2+…+Valn)/(no. measurements)

Ex.: if the operator takes three measurements consecutively, the instrument will

display:

- 1st measurement: main display = measured resistance value (Ex: 0.90Ω)

- 2nd measurement: main display = measured resistance value (Ex: 0.96Ω)

- 3rd measurement: main display = measured resistance value (Ex: 0.93Ω)

EN - 13

+ 28 hidden pages