Megger TDR900 Operating Manual

Megger 4271 Bronze Way

Dallas TX 75237-1017 USA. T +1 (800) 723 2861. (USA only) T +1 (214) 330 3203. (International)

F +1 (214) 337 3038.

Megger PO Box 9007 Valley Forge

PA 19485-9007 USA. T +1 (610) 676 8500.

F +1 (610) 676 8610.

ime Domain Reflectometer

Megger TDR900

USER’S MANUAL

Www. megger.com

W A R N I N G !

SOURCES LI KE S MALL HAND-HELD RADIO TR ANSCE I VE RS, FI X E D STA TION RA DIO AND TE LEVISION TRANSMITTERS, V EHICLE RA DIO TR ANSM ITTERS AND CE L LULAR PHONES GENERATE ELECT ROMAG NETIC RADIATION THAT MAY INDUCE VOLTAGES IN THE TEST LEADS OF THE MULTIMETER. IN SU CH CASES THE ACCURA CY O F T HE MULTIME TE R C ANNOT BE GUARAN TEED DUE TO PHYSICAL REASONS.

Basic Specifications

Maximum Range : Depends upon the V.O.P of the cables under test.

12,000 ft (3.7 km)@ V.O.P 99.9 %

9,800 ft (3.0 km)@ V.O.P 80.0 % 8,000 ft (2.4 km)@ V.O.P 66.0 %

6,200 ft (1.9 km)@ V.O.P 50.0 % Range Selection : Automatic range control Resolution : 20 inches (50 cm)

Accuracy : ± 2 % of reading + 20 inches (50 cm) < 300 ft

(100 m)

± 2 % of reading > 300 ft (100 m) This accuracy is effective for Coaxial Cables up to 8,000 ft, Telephony Cables up to 6,000 ft, and Structured Wiring up to 3,000 ft.

Output Impedance : 25, 50, 75, 100, 125 or 150 ohms Impedance Selection : Automatic output impedance control Velocity Factor : Adjustable from 1.0 % to 99.9 %

Tone Generator : Oscillating 810 - 1100 Hz (5 V

p-p

unloaded) Cable Library : 39 standard cable types Memory Location : 20 for custom cable types Connector : BNC

Input Protection : 250 V RMS Line Voltage Detection : 6.5 V

Warning

The product should not b e connected to any en ergized circuits. Connection to mains supply voltages will damage the Meter and could be hazardous to the user.

The product contains parts that can be damaged by static disc harge. Disc harge the c able to b e test ed be fore connecting the product to the cable.

Read “Safety Information” before using this Meter.

CONTENTS

1. Safety Information

1. Safety Information 3

2. The TDR Cable Length Meter 4

3. Controls, Indicators, and Buttons Overview 5

4. Meter Operation 8

4.1 Principles of operation 8

4.2 How to connect a cable to the Meter 8

4.3 How to set the cable type 9

4.3.1 Selecting a library cable type 9

4.3.2 Cable library for 39 standard cable types 10

4.3.3 Testing cables not included in library 12

4.4 How to determine unknown V.O.P settings 14

4.4.1 Expanding cable library for custom cable types using nonvolatile memory 15

4.5 How to measure cable length 19

4.6 How to check networks (Thin Ethernet) 19

5. Changing the measurement scale between English and Metric 20

6. Measurement accuracy 21

7. Theoretical and actual V.O.P 22

8. Special features 23

8.1 Low battery indication 23

8.2 Overrange indication 23

8.3 Enable or disable the auto-power-off mode 24

8.4 Tone Generator mode 25

8.5 Line Voltage Detection mode 25

9. Maintenance 26

10. Specifications 27 Repair and Warranty

Safety Warnings

This Meter c omplies with the safety requirements of IEC 1010-1 : 2 001. It is designed for use on de-energized circuits o nly, however this Meter is protected against telephone networking voltages (EN 60950 : 1999 Sec. 2.3). Connection to any mains supply voltages may result in damage to the Meter and/or a hazard to

the user. Hence the user must assume responsibility for ensuring his or her own safety.

International Symbols used on the Meter

Caution! Refer to the explanation in this manual.

Double insulation or Reinforced insulation

Battery

Meter complies with current EU Directives.

International Standards

Safety : IEC 1010-1 : 2001 EMC : EN 61326 : 1997+A1: 1998

EMC Standard Category of Pass

ESD IEC 1000-4-2 A EM IEC 1000-4-3 A Burst IEC 1000-4-4 A

Surge IEC 1000-4-5 A Conducted RF IEC 1000-4-6 A

2 3

2. The TDR Cable Length Meter

The Meter is a handheld a nd battery operated instrument capable of measuring cable lengths and finding distance to an open or a short using TDR(Time Domain Reflectometry) techniques, given access to one end only.

The Meter can be used for any cable consisting of at least two insulated metallic elements, one of which may be the sheath or shield of the cable. The Meter has automatic internal matching networks to allow testing of 25 , 50 125 , or 150 cables, which correspond to power, telephony, CATV, and LAN, etc. cables.

The Meter can be closely matched to the cable under test using the menu selection keys. The V.O.P(Velocity of Propagation) value can be similarly adjusted to match the cable under test; thus ensuring an accurate distance measurement.

The M eter incorporates an oscillatin g tone generator, that is d etectable with a standard tone probe (not supplied) available in the marketplaces, for use in the tracing and identification of pairs within a cable .

The Meter displays “ ” message and stops operation if line voltage of the cable under test exceeds 6.5 V when th e Meter is turned on. The BNC terminal is

protected up to 250 V RMS in o rder to prevent it from bein g demaged by its misconnection to live circuits of networking.

, 75

, 100 ,

3. Controls, Indicators, and Buttons Overview

lt hou gh this manu al describe s t he operation of t he Meter for both Me tric measurement and English measurement, all illustrations and examples assume use of the Meter for English measurement.

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( 4 )

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You can s tore u p to 20 cable test resu lts for cu stom cable type s in internal nonvolatile memory and the stored cable library provides quick and easy access to

39 standard c able types, wh ich enables accurate measurement without the necessity of entering V.O.P (Velocity of Propagation).

The on-site measurement scale changing feature enables the Meter to be globally used for both Metric measurement and English measurement without changing the

measurement scale at factory.

The Meter comes with an Alligator Clip adaptor, a user’s manual and a soft carrying case.

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(1) DISPLAY

(3) MENU (on screen) SELECTION BUTTONS

Extra-large backlit (ICON type 7 segment) LCD. When the Meter is turned on, all display segments and symbols appear briefly (during 1.5 seconds) for a selftest and then the Meter defaults the following initial display.

Initial Display

When shipped out of factory The Meter defaults V.O.P of 66.0 % and English scale.

Fig. 1

When turned on after having been used in the field The Meter defaults the V.O.P (e.g. 68.0 %) having been used just before it

was turned off.

Fig. 2

Each setting of the Meter to a measurement function may activate one or more menu selection button settings on the LCD. Press the corresponding menu selection button to select the desired measurement.

Setup Mode

Use the menu selection buttons in order to edit desired setup values as follows :

Button

Pres s to mov e t o nex t Setup.

Press to save all settings and e xit Set up Mo de

when setting is ended.

Function

Press to step to next digit in

setting value.

Press to increase

setting value.

Press to decrease

setting value.

(4) POWER ON/OFF BUTTON

Press the POWER button for more than 1 second to turn the Meter on.

Auto-Power-Off

This Meter is completely turned off after 30 minutes of no activities. Press the POWER

button to turn the Meter on again. This feature can be disabled (refer

to Section 8.).

(5) BACKLIGHT ON/OFF BUTTON or EXIT BUTTON

Press this button for more than 1 second to turn the backlight on and press this button again for more than 1 second to turn it off.

Press this button momentarily to always return to the initial display when the meter is in either SELECT mode or Memory mode. And also press the button momentarily to exit the Tone Generator mode.

(6) MEMORY BUTTON or TONE BUTTON

(2) BNC

A sh ielded connect or for either coaxia l cable or Alligat or Clip adaptor (a standard accessory).

Press this button momentarily to activate the memory mode. The display shows three menu selections : STORE, RECALL and CLEAR

Press this button for more than 1 second to activate the Tone Generator mode. (Press the EXIT button to exit the Tone Generator mode.)

(7) TEST BUTTON

Press this b utton momentarily t o measure length, distance to an open or a short, or V.O.P of cable under test.

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