Consignes De Sécurité Importantes - Textron Tempo PE930 Instruction Manual

Using the Test Set for Troubleshooting Circuits
Some general troubleshooting procedures and tips are provided here. These procedures may
require other tools or equipment that are specific to the communications system installation
trade. For a complete selection of DSV (data-signal-voice) tools, please refer to a Greenlee full-
line catalog, a Tempo DSV catalog, or visit our website at www.tempo.textron.com.
Possible Cause /
Symptom*
Troubleshooting Step
Constant ringing Telephone wire in
contact with an AC
power line
Cross-talk Split pair
Cross connection Direct wiring fault
Noise Hiss (white noise);
pulse dialing causes a
momentary change in
the sound of the noise
Popping, crackling
Momentary or impulse
noise
Power hum Cable imbalance
A long run of telephone
cable near a power line
Ground fault
RFI (radio Split pair
frequency
interference)
*Wet cables may cause most of these symptoms and may cause multiple symptoms to
appear at the same time.
10
Explanation
This is a potentially hazardous situation!
Remove the test set from the line carefully and
immediately.
A split pair (a circuit made up of wires from two
separate wire pairs) will be unbalanced and
prone to cross-talk.
Check for crossed pairs.
This is probably due to water in the cables.
The customer has an older carbon transmitter
type of telephone.
This may be due to an unbalanced cable, nearby
power switch gear, or similar equipment.
Break the circuit down into sections and check
each section for an imbalance.
Contact the local electric utility.
Check for the presence of AC line voltage. If AC
line voltage is present, measure the level. If it is
typical line voltage, contact the local electric
utility.
An unbalanced pair near a radio transmitter will
be prone to RFI. Adding radio filters can reduce
the interference on the line (the symptom), but
does not solve the imbalance (the problem). To
troubleshoot, break the circuit down into
sections and check each section for split pairs
or a resistive imbalance.
Improperly removed bridge taps may also
introduce RFI. Bridge taps, which were once used
for party-line service (multiple users sharing a
cable pair), were often disconnected but left in
place, with a stub section of cable still connected.
This stub section can act as an antenna and
induce radio signals into the circuit.
Consignes de sécurité importantes
Risques de décharge électrique :
Un contact avec des circuits sous tension peut entraîner des
blessures graves, voire mortelles.
Inspecter le vérificateur et le cordon pour y détecter toute trace d'usure ou de
dommages. Remplacer des composants usés, endommagés ou manquants avec des
pièces de rechange de Tempo. Un composant endommagé peut défaillir et entraîner ainsi
des blessures ou des dommages matériels.
N'effectuer aucune réparation ni aucun entretien autre que ceux indiqués dans ce manuel.
L'inobservation de cette précaution peut entraîner des dommages matériels ou des
blessures.
Utiliser cet outil uniquement pour l'usage prévu par le fabricant. Toute utilisation autre
que celle décrite dans ce manuel peut entraîner des blessures ou des dommages
matériels.
Remplacer les piles faibles ou déchargées dès qu'une de ces deux conditions est
détectée.
PE930
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