Fluke 1625 User Manual

®

1625

Earth/Ground Tester

Users Manual

January 2006

© 2006 Fluke Corporation, All rights reserved. Printed in USA All product names are trademarks of their respective companies.

LIMITED WARRANTY AND LIMITATION OF LIABILITY

Each Fluke product is warranted to be free from defects in material and workmanship under normal use and service. The warranty period is two years and begins on the date of shipment. Parts, product repairs, and services are warranted for 90 days. This warranty extends only to the original buyer or end-user customer of a Fluke authorized reseller, and does not apply to fuses, disposable batteries, or to any product which, in Fluke's opinion, has been misused, altered, neglected, contaminated, or damaged by accident or abnormal conditions of operation or handling. Fluke warrants that software will operate substantially in accordance with its functional specifications for 90 days and that it has been properly recorded on non-defective media. Fluke does not warrant that software will be error free or operate without interruption.

Fluke authorized resellers shall extend this warranty on new and unused products to enduser customers only but have no authority to extend a greater or different warranty on behalf of Fluke. Warranty support is available only if product is purchased through a Fluke authorized sales outlet or Buyer has paid the applicable international price. Fluke reserves the right to invoice Buyer for importation costs of repair/replacement parts when product purchased in one country is submitted for repair in another country.

Fluke's warranty obligation is limited, at Fluke's option, to refund of the purchase price, free of charge repair, or replacement of a defective product which is returned to a Fluke authorized service center within the warranty period.

To obtain warranty service, contact your nearest Fluke authorized service center to obtain return authorization information, then send the product to that service center, with a description of the difficulty, postage and insurance prepaid (FOB Destination). Fluke assumes no risk for damage in transit. Following warranty repair, the product will be returned to Buyer, transportation prepaid (FOB Destination). If Fluke determines that failure was caused by neglect, misuse, contamination, alteration, accident, or abnormal condition of operation or handling, including overvoltage failures caused by use outside the product’s specified rating, or normal wear and tear of mechanical components, Fluke will provide an estimate of repair costs and obtain authorization before commencing the work. Following repair, the product will be returned to the Buyer transportation prepaid and the Buyer will be billed for the repair and return transportation charges (FOB Shipping Point).

THIS WARRANTY IS BUYER'S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. FLUKE SHALL NOT BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES, INCLUDING LOSS OF DATA, ARISING FROM ANY CAUSE OR THEORY.

Since some countries or states do not allow limitation of the term of an implied warranty, or exclusion or limitation of incidental or consequential damages, the limitations and exclusions of this warranty may not apply to every buyer. If any provision of this Warranty is held invalid or unenforceable by a court or other decision-maker of competent jurisdiction, such holding will not affect the validity or enforceability of any other provision.

Fluke Corporation	Fluke Europe B.V.
P.O. Box 9090	P.O. Box 1186
Everett, WA 98206-9090	5602 BD Eindhoven
U.S.A.	The Netherlands

11/99

Table of Contents

Title	Page
Introduction ..........................................................................................	1
Models and Accessories........................................................................	3
Safety Instructions ................................................................................	4
Qualified Staff ..................................................................................	5
Setup .....................................................................................................	5
Unpacking.........................................................................................	5
Checking the Scope of Delivery .......................................................	5
General .................................................................................................	6
Additional Accessories .........................................................................	6
Assembly ..............................................................................................	7
Description of Functions.......................................................................	7
Measurement of Interference Voltage (UST) .....................................	8
Measurement of Interference Frequency (FST)..................................	8
Measurement of Earthing Resistance (RE)........................................	9
Selective Measurement of Earthing Resistance (RE A) ................	9
Resistance Measurement (R~) ..........................................................	9
Low Resistance Measurement (RF).................................................	9
Checking for Correct Measuring Connection ...................................	9
Beeper...............................................................................................	9
LO-BAT............................................................................................	10
Specifications........................................................................................	10
Measurement of Interference Voltage DC + AC (UST) .....................	13
Measurement of Interference Frequency (FST)..................................	13
Earthing Resistance (RE)...................................................................	13
Selective Measurement of the Earthing Resistance (REA)............	17
Resistance Measurement (R~) ..........................................................	18
Resistance Measurement (RF).........................................................	19
Compensation of Lead Resistance (RK) ............................................	20
Description of the Operating Elements .................................................	21
Description of Display Elements ......................................................	23
Procedure of Measurements..................................................................	24
POWER ON Functions .................................................................	25
Operation ......................................................................................	26
Checking of Correct Measuring Connection (Socket Allocation). 30
Safety Control Measurements.......................................................	31

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Measurement of Interference - Voltages and Frequencies................	31
Measurement of Earthing Resistances..............................................	32
3-pole/4-pole Measurement of Earthing Resistance .....................	33
Measurement of Single Earth Electrode Resistances in
Mesh Operated Earthing Systems Using Selective Clamp
Method .........................................................................................	36
3-pole/4-pole Measurement of Single Earth Electrode
Resistances ...................................................................................	37
Measurements on High Voltage Pylons........................................	39
Correcting Clip-on Transformer Errors ........................................	42
Compensation of Earth Electrode Connecting Lead.....................	44
Measurement of Soil Resistivity.......................................................	45
Measurement of Resistances ............................................................	48
Resistance Measurement (R~)......................................................	48
Resistance Measurement (RF).....................................................	49
Compensation of Measuring Lead Resistance..............................	50
Changing of All Data Settings with Personalized CODE.................	51
Storing a Code..............................................................................	53
Deleting a Code............................................................................	54
Description of Displays ........................................................................	55
Care and Maintenance ..........................................................................	60
Replacing Batteries...........................................................................	61
Recalibration ....................................................................................	62
Storage..............................................................................................	62
Specifications .......................................................................................	64
Principle of Operation ..........................................................................	65
Purpose.............................................................................................	65
Operation..........................................................................................	68
Settings on the Tester ...................................................................	69
Applications .....................................................................................	70
Description of Displays ................................................................	72

ii

List of Tables

	Table	Title	Page
1.	Models and Accessories	.................................................	3
2.	Electrical Measurement Specifications ..........................		14
3.	Description of Displays..................................................		56

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iv

List of Figures

	Figure	Title	Page
1.	Fluke 1625 Earth/Ground Tester....................................		2
2.	Description of Functions	................................................	8
3.	Display ...........................................................................		10
4.	Operating Elements........................................................		21
5.	Display Elements ...........................................................		23
6.	Operational Modes .........................................................		27

7.Measurement of Interference -

	Voltages and Frequencies...............................................	32
8.	Earthing Resistances Measurement - Method................	33

9.3-pole/4-pole Measurement of Earthing Resistance -

Process............................................................................	34
10. Earth Resistance - Maximum Permissible Value ...........	35

11.Measurement of Single Earth Electrode Resistances in

Mesh Operated Earthing Systems ..................................

36

12.3-pole/4-pole Measurement of Single Earth

Electrode Resistances.....................................................

37

13.Measuring the Earthing Resistance without

	Disengaging the Overhead Earth Wire...........................	40
14.	Correcting Clip-on Transformer Errors..........................	43
15.	Compensation of Earth Electrode Connecting Lead ......	44
16.	Measurement of Soil Resistivity ....................................	45
17.	Resistance Measurement (R~) .......................................	48
18.	Resistance Measurement (RF) ......................................	49
19.	Evaluation of Measured Value.......................................	50
20.	Compensation of Measuring Lead Resistance ...............	51

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vi

Earth/Ground Tester

Introduction

At locations involving the generation, distribution and consumption of electrical energy, certain safety measures must be met in order to protect human life. In many cases, these safety measures are national and international regulations which must be checked regularly. Grounding, the connection of exposed conductive parts to the earth in case of a fault, represents the most fundamental safety measure. There are requirements for grounding of transformers, high and medium voltage power pylons, railway tracks, tanks, vats, foundations and lightning protection systems.

The effectiveness of grounding systems should be checked using a ground test instruments such as the 1625 which checks the effectiveness of connections to the ground. The 1625 provides the perfect solution by combining the latest technology into a compact, field-rugged and extremely easy to use instrument. In addition to performing standard 3- and 4-pole ground resistance measurements, an innovative process accurately measures individual earth electrode resistances in single and meshed earthed systems without disconnecting any parallel electrodes. One specific application of this capability is quick and accurate measurement of power pylon grounds. The 1625 also incorporates automatic frequency control (AFC) to minimize interference. Before measuring, the instrument identifies existing interference and selects a measurement frequency to minimise its effect. The 1625 incorporates microprocessor controlled automatic measurements including checking probe hookup to ensure that measurements are taken correctly. It measures all probe ground resistances to ensure reliable, repeatable results. Probe resistance and auxiliary earth resistance are also measured and displayed.

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Notes

•The terms earth and earthing also refer to ground and grounding and is used interchangeably throughout this manual.

•For stakeless earth resistance measurements, the EI-1625 must be purchased. (The EI-1625 comes standard with the 1625 Kit). Refer to Appendix A for a complete set of operating information including specifications.

•Selective measurements are described in the main section of this manual.

Figure 1 displays the Fluke 1625 Earth/Ground Tester:

	1625 EARTH / GROUND TESTER
START	ST		H/C2
TEST
DISPLAY			S/P2
MENU
		AC
	Earth/Ground Resistance 300 k	Resistance	DC Low Resistance 3k
		300 k
	RA	R	R
	4 POLE	2 POLE
			2 POLE
	3 POLE
	4 POLE		4 POLE
CHANGE	3 POLE		ES/P1
ITEM
	OFF
SELECT			E/C1
			edw001.eps

Figure 1. Fluke 1625 Earth/Ground Tester

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Earth/Ground Tester

Models and Accessories

Models and Accessories

Table 1 lists the models and accessories.

Table 1. Models and Accessories

Description	Item/Part Number
Earth Ground Tester - Basic	Fluke-1625
(Includes manual, 2 leads and 2 clips)
Earth Ground Tester - Fully Loaded	Fluke-1625 Kit
(Includes manual, 2 leads and 2 clips,
ES162P4, EI-1623)
Service Replacement Kit	Fluke-162x-7001
(Includes 2 Leads, 2 Clips)
Stake Set for 3 Pole Measurement	ES-162P3
(Includes three stakes, one 25 m cable
reel, one 50 m cable reel)
Stake set for 4 Pole Measurement	ES-162P4
(Includes four stakes, two 25 m cable
reels, one 50 m cable reel)
Selective/Stakeless Clamp Set for	EI-1625
1625. (Includes EI-162X and EI-
162AC and 2-3 wire adapter cable)
Clip-on Current Transformer (sensing)	EI-162X
with shielded cable set
Shielded Cable (Used w/EI-162X	2539195
Clamp)
Clip-on Current Transformer (inducing)	EI-162AC
12.7 Inch (320mm) Spilt Core Trans-	EI-162BN
former
2-3 Wire Adapter Cable for 1625 for EI-	2577171
162AC Current Transformer
Earth Stake	2539121
Cable Reel w/25m Wire	2539100
Cable Reel w/50m Wire	2539117
1625 Users Manual	2560348

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Safety Instructions

W Warning

This measuring equipment is only to be operated by qualified staff and in accord with its technical data in compliance with the safety precautions and instructions set forth below. In addition, use of this equipment requires compliance with the legal and safety instructions pertaining to the specific application in question. Similar precuations apply to the use of accessories.

Caution

Operation of electrical equipment inevitably causes certain parts of such equipment to carry dangerous voltage. Noncompliance with precautions may therefore cause major physical or material damage.

Fault-free and reliable operation of this instrument requires suitable transport and storage, setting-up and assembly, as well as care in operation and maintenance.

If there is reason to believe that risk-free operation is no longer possible, the instrument should be switched off immediately and protected against accidental restarting. Risk-free operation shall be deemed to be no longer possible if and when the instrument

•shows visible damage,

•fails to work in spite of functioning batteries,

•has been exposed for some time to unfavorable conditions ( e.g. storage beyond the permissible climatic limits without adaptation to the ambient climate, dewing etc.),

•has been exposed to major strain during transport ( e.g. been dropped from some height without visible external damage etc.), or

•shows " E1 ... E5 " on the display.

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Earth/Ground Tester

Setup

Qualified Staff

Consists of persons familiar with the setting up, assembly, starting up and operation of the product and possess the qualifications required for such activities, such as

•training, instruction and/or authorization to perform the following operations on circuits and equipment according to safety engineering standards: switching on and off, disconnecting, earthing/grounding, labeling;

•training or instructions according to safety engineering standards in the care and main tenance of adequate safety equipment.

•training in rendering first aid.

Setup

Unpacking

Check delivery for damage during transport. Keep the packing material for later transport and check scope of delivery.

Checking the Scope of Delivery

Upon unpacking immediately check the accessories for missing parts. The accessories supplied are listed on page 2.

Caution

Although the instrument is easy to operate please read these operating instructions carefully for safety reasons and in order to make optimum use of the instrument.

The measuring functions are only all activated when the instrument is connected.

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General

Microprocessor controlled universal earth resistance meter with fully automated measuring frequency selection process as well as automatic testing of probeand auxiliary earth electrode resistances and possible interference voltages as per DIN IEC61557-5/EN61557-5.

•Measurement of interference voltage (UST)

•Measurement of interference frequency (FST)

•Measurement of probe resistance (RS)

•Measurement of auxiliary earth electrode resistance (RH)

•Measurement of earthing resistance 3pole, 4pole, (RE) with or without using the external clip-on current transformer for selective measurement of single earthing branches in mesh operated earthing systems

A

•Resistance measurement 2pole with AC voltage (R~)

•Resistance measurement with DC voltage 2pole, 4pole, (RF)

With its various possibilities of measurement and the fully automated measuring sequence control (incl. automatic frequency control AFC), this instrument offers the latest measuring technology in the field of earthing resistance measurements. By means of the selectable limit input with visual and accoustical confirmation/error message and with the code programmable and customer defined special functions, e.g. measuring voltage 20 V (for agricultural systems), earthing impedance R* (measuring frequency 55 Hz) switched on or off etc., these instruments are individually programmable for use as a simple meter as well as a high end fully automated measuring device.

Additional Accessories

An external current transformer with a transformation ratio between 80 and 1200:1 for the measurement of a single branch in mesh operated earthing systems is available as an option and enables the user to measure on high voltage pylons without seperating the overhead earth wires or earth strips at the bottom of the pylons and also to measure lightning protection systems without seperating the individual lightning protection wires.

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Earth/Ground Tester

Assembly

Assembly

The instrument is made up of two parts:

1.The base part which contains the measuring electronics.

2.The protective housing.

The functions are selected with the central rotary switch. Four rubber buttons, which start measurements, read out supplementary measuring values and select special functions, are located on the left hand side of the front panel. This design enables quick and clear one-hand operation.

The measured values are displayed on a liquid crystal display with correct decimal point and unit. Various additional special characters indicate measuring mode, operating condition and error messages.

The auxiliary power supply consists of 6 x 1.5 V batteries (IEC R6 or LR6 or type AA).

This device has been developed, designed and manufactured in compliance with quality system DIN ISO 9001.

Description of Functions

The following flowchart presents a description of the functions of the 1625 Earth/Ground Tester.

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EXT
H
S	Switching
ES
E
Voltage		Current	Source		Undervoltage	Supply
measurement		measurement			detection	voltage
ADC		Processor		LCD	Display
Comp				driver
		Relais	Rotary selector
		driver	switch buttons
						edw003.eps

Figure 2. Description of Functions

Measurement of Interference Voltage (UST)

Fullwave rectification for DC and AC (DC without operational sign, AC signal sinus calibrated for r.m.s. values). If limit values are exceeded no measurement will be started.

Measurement of Interference Frequency (FST)

For interference voltage >1 V its frequency is derived from the period time.

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Earth/Ground Tester

Description of Functions

Measurement of Earthing Resistance (RE)

The earthing resistance is determined by a 3- or 4-pole current and voltage measurement. The measuring voltage is a square pulse AC voltage with 48 / 20 V and a frequency of 94, 105, 111 or 128 Hz. The frequency can be selected manually or automatically (AFC).

Selective Measurement of Earthing Resistance (RE A)

Measurement of a single earth electrode in a mesh operated (parallel) earthing system. The current flowing through the single earth electrode is measured with an external current transformer.

Resistance Measurement (R~)

The resistance is determined by a 2 pole current and voltage measurement. The measuring voltage is a square pulse AC voltage with 20 V and a frequency of 94, 105, 111 or 128 Hz. The frequency can be selected manually or automatically (AFC).

Low Resistance Measurement (RF)

The resistance is determined by DC current and voltage measurement. 2- as well as 4-pole measurement is possible. The short circuit current is > 200 mA. The resistance of both current directions is measured and stored.

Checking for Correct Measuring Connection

The processor checks if the measuring lead is properly connected according to the selected function via isolated, two piece contacts, inside of each 4 mm (banana) input socket, in combination with detection circuitry. A wrong or missing connection is indicated by an optical or acoustical signal.

Beeper

The built in beeper has two functions:

1.Giving messages if set limit values are exceeded.

2.Indicating dangerous conditions or maloperation. Controlling is done by means of the microprocessor.

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LO-BAT

Supervision of the battery charge status is done with a comparator circuit. Via microprocessor, a drop in battery capacity down to typ. 10 % of its specified value is indicated on the display with symbol LO-BAT.

Specifications

General:	Microprocessor controlled, fully automated earth
	measuring instrument with additional functions
Measuring function:	interference voltage and frequency, earthing resis-
	tance 3- and 4-pole with / without clip-on current
	transformer, resistance 2-pole with AC, 2- and 4-pole
	with DC
Display	4 digit (2999 Digit) - 7 segment liquid crystal display,
(see Figure 4):	digit size 18 mm with supplementary signs and active
	illumination.

ST

edw004.eps

Figure 3. Display

10

			Earth/Ground Tester
			Specifications
Operation:	Central rotary switch and function keys
Working temperature range:	-10 °C		… +50 °C
Operating temperature range:	0	°C	… +35 °C
Nominal temperature range:	18	°C	… +28 °C
Storage temperature range:	-30 °C		… +60 °C

Note

The chart of four temperature ranges for the instrument exist to satisfy European Standards requirements; the instrument can be used over the full Working temperature range by using the temperature coefficient to calculate accuracy at the ambient temperature of use.

Temperature coefficient:	± 0.1 % of range / Kelvin
Operating errors:	refer to operating temperature range and RH
	< 20 RE, RS < 100 RE

The maximum percentage operating error within the measurement range does not exceed ± 30 % with the measured value as fiducial value, as determined in accordance with TABLE 1.

The operating error applies under the rated operating conditions given in IEC1557-1 and the following:

•injection of series interference voltages with system frequencies of 400 Hz, 60 Hz, 50 Hz, 16 2/3 Hz or with d.c. voltage respectively across the terminals E (ES) and S. The r.m.s. value of the series interference voltage shall be 3 V;

•resistance of the auxiliary earth electrode and of the probes: 0 to 100 x RA but ≤ 50 kΩ;

•system voltages between 85 % and 110 % of the nominal voltage and between 99 % and 101 % of the nominal system frequency for measuring equipment with a mains supply and/or measuring equipment deriving its output voltage directly from the distribution system.

Limits of error:	refer to nominal temperature range
Climate class:	C1 (IEC 654-1), -5 °C...+45 °C, 5 %...95 % RH
Type of protection:	IP 56 for case, IP 40 for battery door according to
	EN 60529

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Max voltage:	Wsocket Ato socket EFGH
	Urms = 0 V
	Sockets ” E ES S H " to each other in any com-
	bination, max. Urms= 250 V (pertains to misuse)
EMC (Emission Im-	IEC 61326-1:1997 Class A
munity):
Quality standard:	developed, designed and manufactured to comply
	with DIN ISO 9001
External field influ-	complies with DIN 43780 (8/76)
ence:
Auxiliary power:	6 x	1,5 V alkali-manganese-batteries (IEC
		LR6 or type AA )
Battery life span:	with IEC LR6/type AA: typ. 3000 measurements
	(RE+RH ≤ 1 kΩ)
	with IEC LR6/type AA : typ. 6000 measurements
	(RE + RH >10 kΩ)
Dimensions:	240 mm (W) x 220 mm (D) x 90 mm ( H )
Weight:	≤ 1.1 kg without accessories
	≤ 5.5 kg incl. accessories and batteries in carrying
	case
Case material:	NORYL, shock -and scratch proof thermoplast

12

Earth/Ground Tester

Specifications

Measurement of Interference Voltage DC + AC (UST)

Measuring method:

fullwave rectification

Measuring

Display

Resolu-

Frequency

Limits of Er-

Range

Range

tion

Range

ror

1…50 V

0.0…50 V

0.1 V

DC/AC

± (5% of

45…400 Hz

reading +5

sine

digit)

Measuring sequence:

approx. 4 measurements /s

Internal resistance:

approx. 1.5 MΩ

Max. overload:

Urms = 250 V

Measurement of Interference Frequency (FST)

Measuring method:

Measurement of oscillation period of the interfer-

ence voltage

Measuring

Display Range

Resolution

Range

Limits of

Range

Error

16.0 … 400

16.0…299.9…99

0.1 … 1 Hz

1 V …

± (1% v. mv

Hz

9 Hz

50 V

+2 digit)

Earthing Resistance (RE)

Measuring method:

current and voltage measurement with probe

as IEC61557-5

Open circuit voltage:

20 / 48 V, AC

Short circuit current:

250 mA

AC

Measuring frequency:

94 , 105 , 111 , 128 Hz selected manually or

automatic.(AFC) 55 Hz in function R*

Noise rejection:

120 dB ( 16 2/3, 50 , 60, 400 Hz )

Max. overload:

Urms = 250 V

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Table 2. Electrical Measurement Specifications

				Requirements
	Intrinsic Er-	Reference Con-		or Test in Ac-	Type
	ror or Influ-	ditions or Speci-	Designation	cordance with
					of
	ence Quan-	fied Operating	Code	the Relevant
					Test
	tity	Range		Parts of
				IEC 1557
	Intrinsic error	Reference condi-	A	Part 5, 6.1	R
		tions
	Position	Reference posi-	E1	Part 1, 4.2	R
		tion
		± 90°
	Supply volt-	At the limits	E2	Part 1, 4.2,	R
	age	stated by the		4.3
		manufacturer
	Temperature	0 °C and 35 °C	E3	Part 1, 4.2	T
	Series inter-	See 4.2 and 4.3	E4	Part 5, 4.2,	T
	ference volt-			4.3
	age
	Resistance	0 to 100 x RA	E5	Part 5, 4.3	T
	of the probes	but ≤ 50 kΩ
	and auxiliary
	earth elec-
	trodes
	System fre-	99 % to 101 % of	E7	Part 5, 4.3	T
	quency	the nominal fre-
		quency
	System volt-	85 % to 110 % of	E8	Part 5, 4.3	T
	age	the nominal volt-
		age
	Operating			Part 5, 4.3	R
	error	B = ±( A +1,15 E12 E22 E32 E42 E52 E62 E72 E82

14

									Earth/Ground Tester
									Specifications
		A	=	intrinsic error			B[%]= ±		B		x 100%
		En		=	variations			fiducial value
		R	=	routine test
		T	=	type test
		Measuring							Instrinsic	Max. Op-
					Display Range		Resolution				erating
		Range							Error
											Error
					0.001 Ω...2.999 Ω		0.001 Ω
					3.00 Ω...29.99 Ω		0.01 Ω
		0.020 Ω			30.0 Ω...299.9 Ω		0.1 Ω		± ( 2 % of		± ( 5% of
									mv +2 digit )		mv +5
		300 kΩ			0.300 kΩ...2.999 kΩ		1 Ω
											digit )
					3.00 kΩ...29.99 kΩ		10 Ω
					30.0 kΩ...299.9 kΩ		100 Ω

Measuring time:

Additional error because of probe-and auxiliary earth electrode resistance:

Measuring error of RH and RS:

Max. probe resistance:

Max. auxiliary earth electrode resistance:

typ. 8 sec. with a fixed frequency

30 sec. max. with AFC and complete cycle of all

measuring frequencies

RH (RS + 2000Ω) × 1.25× 10− 6% + 5digits RE

typ. 10 % of RE + Rs + RH

≤1 M Ω

≤1 M Ω

Automatic check if error is kept within the limits required by IEC61557-5.

If after a measurement of probe-, auxiliary earth electrodeand earthing resistance, a measurement error of higher than 30 % is assumed because of the in-

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fluencing conditions (see diagramm), the display shows a warning symbol W and a notice that RS or RH are too high.

F				3000	1000
1000%
					RH/RE= 300
100%					100
					30
10%					10
					3
1%					1
					0,3
0,1%
10	100	1k	10k	100k	1M	RS
						edw005.eps

Automatic switchover of measuring resolution in dependence to auxiliary earth electrode resistance RH:

RH with Umeas = 48 V		RH with Umeas = 20 V	Resolution
< 300 Ω		< 250 Ω	1 mΩ
<	6 kΩ	< 2,5 kΩ	10 mΩ
<	60 kΩ	< 25 kΩ	100 mΩ
< 600 kΩ		< 250 kΩ	1 Ω

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Earth/Ground Tester

Specifications

Selective Measurement of the Earthing Resistance

(REA)

Measuring method:			Current and voltage measurement with probe as per
			EN61557-5 and current measurement in the individual
			branch with additional current transformer (patent ap-
			plied for).
Open circuit volt-			20 / 48 V AC
age:
Short circuit current:			250 mA AC
Measuring fre-			94, 105, 111, 128 Hz selected manually or automati-
quency:			cally (AFC), 55 Hz (R*)
Noise rejection:			120 dB (16 2/3 , 50 , 60 , 400 Hz)
Max. overload:			max. Urms = 250 V (measurement will not be started)
Measuring		Display Range		Resolution	Intrinsic	Operating
Range					Error *	Error *
		0.001...2.999 Ω		0.001 Ω
		3.00...29.99 Ω		0.01 Ω
0.020 Ω...		30.0...299.9 Ω		0.1 Ω	± (7 % of	± (10% of m.v.
					m.v. +2	+5 digit)
30 kΩ		0.300...2.999 kΩ		1 Ω
					digit)
		3.00...29.99 kΩ		10 Ω

* With recommended current clamps / transformers.

Additonal error because of probeand auxiliary earth typ.electrode resistance:

Measuring error of RH and RS:

Measuring time:

RH (RS + 2000Ω) × 1.25× 10−6% + 5digits

RETOTAL

typ.of 10% of RETOTAL + RS + RH

typ. 8 sec. with a fixed frequency 30 sec.max. with AFC and complete cycle of all measuring frequencies

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Minimal current in single	0.5 mA	with transformer (1000:1)
branch to be measured:
	0.1 mA	with transformer (200:1)
Max. interference current	3 A	with a transformer (1000:1)
through transformer:

Resistance Measurement (R~)

Measuring method:			current and voltage measurement
Measuring voltage:			20 V AC, square pulse
Short circuit current:			> 250 mA AC
Measuring frequency:			94, 105, 111, 128 Hz selected manually or auto-
			matically (AFC)
Measuring		Display Range		Resolution	Intrinsic	Operating
Range					Error	Errors
		0.001 Ω ... 2.999 Ω		0.001 Ω
		3.0 Ω ... 29.99 Ω		0.01 Ω
0.020 Ω...		30 Ω ... 299.9 Ω		0.1 Ω	± ( 2 %	± ( 5% of m.v.
					of m.v.	+5 digit )
300 kΩ		300 Ω ...	2999 Ω	1 Ω
					+2 digit )
		3.0 kΩ ... 29.99 kΩ		10 Ω
		30.0 kΩ ... 299.9 kΩ		100 Ω
Measuring time:			typ. 6 sec.
Max. interference voltage:			24 V, with higher voltages measurement will not
			be started
Max overload:			Urms max. = 250 V

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							Earth/Ground Tester
							Specifications
Resistance Measurement (RF)
Measuring method:				currentvoltage measurement as per IEC61557-4
				possible
Open circuit voltage:				20 V DC
Short circuit current:				200 mA DC
Formation of measured				with 4-pole measurement wires on H, S, ES can
value:				be extended without additional error.
				Resistances >1 Ω in wire E can cause additional
				error of 5m Ω/Ω.
	Measuring		Display Range			Resolution	Intrinsic	Operating
	Range						Error	Error
			0.001 Ω ... 2.999 Ω			0.001 Ω
	0.020 Ω		3.0 Ω ... 29.99 Ω			0.01 Ω	±( 2 % of	±( 5% of
							m.v. +2	m.v. +5
	3 kΩ		30.0 Ω ... 299.9 Ω			0.1 Ω
							digit)	digit)
			300 Ω ...	2999 Ω		1 Ω
Measuring sequence:				approx. 2 measurements/s
Measuring time:				typ. 4 sec. incl. reversal of polarity (2 pole or 4
				pole)
Max. interference voltage:				≤ 3 V AC or DC, with higher voltages measure-
				ment will not be started
Max inductivity:				2 Henry
Max. overload:				Urms = 250 V

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