AGMel A910 User Manual

No display
dim display

Dead battery.
Instrument failure.

Unstable
measurement

Dead battery.
Cable to test not faulted.
Measurement carried out
immediately after a voltage
test.
Cable to test too short.
Cable to test not connected.
Broken test leads.
Instrument failure.

AGMel

IA910 Rev 2 04/13

2002/95/EC

EXAMPLE

Faulted cable is 25000 meters long.
The value read in position ”E”, LE, is

24.7%, the value LB is 24.7 %.

the cable has only one contact at
distance:

24.7 x 25000 = 6175

100

meters from the Outside end of the
cable.

SPECIFICATIONS

Can test cables with a loop resistance
≥ 5mΩ (≈ 90 m @ 300 mm2) and
≤ 30 kΩ.

Range: > 100 km @ 300 Ω/km
Basic accuracy: ± 0.1 % ± 1 digit
Maximum measuring current: 1A
Maximum applied voltage: 70 mV
Power supply: 7.2 ÷ 9V , 6 x AA size

Alkaline or NiCd/NiMh batteries

Battery life: 1000 measur. @ 100 mΩ
Weight: 520 g
Dimensions: 110 x 204 x 41 mm

USER MANUAL

Short circuit locator

for metallic cables

Mod. A910

SERVICING INFORMATION

If you have questions or need further
assistance, please email us at
[email protected]

Our complete catalog can be viewed,
printed or book marked from our
website: www.agminstruments.com

AGM Elettronica

Via Marziale, 9
80067 Sorrento (NA)
Italy

Tel [phone]
Fax[phone]
www.agminstruments.com
E-mail: [email protected]

TROUBLESHOOTING

CALIBRATION

Our instruments are calibrated using
the following standards

Datron 4705 Autocal Multifunction Calibrator
Yokogawa 7563 Precision Digital Thermometer
GenRad 1686 Digital Capacitance Meter
Agilent 66309D Mobile Communic. Source
HP 34401 Multimeter
HP 34970A Data Acquisition Unit
Burster 1424 IEEE488 High Precision Decade
Tettex 3200/BU Standard Resistor
AOIP 0,01 Standard ResistorΩ
Tettex Decade Capacitors
ARCO Standard Capacitors
JBC 5001 Standard Capacitor
Lecroy LT264ML Oscilloscope
Haefely PU12 Impulse tester
Schaffner NSG431 Electr. Discharge Simulator
Lecroy 9109 Arbitrary Function Generator
Norbar 40051 Torque meter
HP 3577A Network Analyzer

1 probes connector 4 battery holder

2

display

5 measure mode select

3 measure switch

DESCRIPTION

The A910 is a short circuit locator for
electric, telephone and power cables
wind on the reel; it gives the position
of the fault from the inside or outside
end of the cable, in percentage to the
total cable length.

HOW TO USE IT

Ground the cable to be tested from
any electrical charges.

If wire “A” is short with “B”, connect
the crocodile clips to the cable:

1) the crocodile clip “I” to “A”
from the inside end.

2 the crocodile clip “E” to “A”

from the outside end.

3) the crocodile clip “COM” to
“B” from the outside end.

Perform a calibration test:
turn the measure mode knob to “Ref”
and push the measure switch, the
display will show 100.0 ± 0.1 %,
otherwise: :

a) the cable has a total

resistance below 5 mΩ

Connect wire with lead

A E

B COM

B COM

A I

Lead connections

b) the cable has some

electrostatic charges within

c) the test leads are broken.

Turn the measure mode knob to “E”
and push the measure switch, read on
the display the value LE, length of the
cable (in percentage to the total cable
length) from clip “E” to the short.

Switch the crocodile clip “COM”

to wire “B” from the inside end

push the measure switch, read on the
display the value LB; if LE = LB ± 0.1
%, than the cable has just one short at
distance:

(Value LE) x (total length of cable)

100

from the outside end of the cable.

If LE ≠ LB ± 0.1 %, the cable has
more than one short and the distance
to fault is calculated making use of the
program supplied with the instrument.

To measure the distance to fault from
the inside end of the cable, turn the
measure mode knob in position “I”
and push the measure switch.

To remove the battery door push the two
gray plastic tabs.

Be careful to observe battery

polarity during installation !

WARNINGS AND SAFETY RULES

The locator is protected against
electrical charges, but in some
conditions these charges on the wire
can accumulate and can be
dangerous for the technician,
therefore

always ground the cable
before any measurement

Do not short the clips “I” with “E” for a
long time, otherwise the battery life
will be reduced.

The calibration test is possible only
after a cable is connected.

The crocodile clips “I” and “E” are
special Kelvin clips, do not force the

opening.

1

2

3

4

5