4
The transmitter meter will pulse even though
the fault may not be breaking over. The
neutral ground rod will be seen through the
transformer windings and this will provide a
conductive path to the soil. These earth
currents will be received by the transmitter
and will cause the transmitter meter to
pulse.
If the transmitter is connected to a cable
that is not isolated at both ends, the voltage
control should be set at 3000 volts to insure
the fault will break over. When the fault
breaks over, the voltage will automatically
reduce to a low level and fault currents will
automatically increase. This will not damage
the cable or transformer.
3. If connected into a live 120 volt circuit, a
high 60 Hz current can be entering the ground
detector direction indicator to oscillate under some conditions.
If the detector direction indicator starts to oscillate or produce erratic readings that cannot
be corrected with the balance control, stop the fault locate and isolate the cable. A high
60 Hz current can prevent the detector from responding to the transmitter’s fault current.
00
When the Fault Locate-Tone Trace function switch is in the TONE TRACE position, the Fault
for fault locating to be used for placing a tone on the cable for cable tracing. Even if the cable
location and route can be described, the operator should always use a good cable locator and
trace out the actual route of the cable to be tested. If the operator is not following the correct
route of the faulted cable, a lot of time and energy can be spent without much success.
The transmitter is powered by two methods:
1. 120 volt line (60 Hz) 110/230 universal input 90 - 264
2. Internal rechargeable 12 volt battery
A good rule of thumb is to charge at least two hours for each hour of operation. A Red LED on the
face of the transmitter front panel indicates when the battery is being charged from a 120 volt wall
outlet and will remain on until disconnected from the outlet. The Green LED will turn on when the
battery is fully charged. A 3/4 amp slow blow fuse is also used in the power supply from the AC 120
volt line cord. If the battery cannot be charged from the AC line cord, this fuse should be checked.
Note: The meter is not useful for
measuring actual fault resistance.
Claims made to the contrary for any
such instrument overlook one item. The
resistance of the earth is also involved.
The output circuit is from the transmitter
output, through the cable, through
the fault, and through the earth back
to the ground rod and back into the
transmitter. This total circuit is the total
resistance and each component can
vary. In other words, instruments using
a meter to measure fault resistance
tell the operator only ,what the total
loop resistance is, which includes but
is unlikely to represent, the actual fault
resistance.
