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5 Loc3 25-Watt Transmitter Functions and Operation
5.8 Transmitter Modes
WARNING
Always connect the transmitter to the target line following your company's procedures. These
operations should only be performed by authorized personnel. Always make connections before
switching on the unit. Turn the transmitter off before disconnecting.
When the 25-watt transmitter is powered on without connection leads a “NO CONNECTION” message
will appear on the LCD. Power off the transmitter and insert the connection leads, and procced with
power up.
NO CONNECTION
25-Watt Transmitter (Only)
5.8.1
Direct Connection Mode
The
Direct Connection
mode is automatically selected by plugging a connection lead into the output socket. An icon confirming
the direct connection mode is shown on the display. The wave in the icon fluctuates when the transmitter is operating. The direct
connection lead consists of two colored cables with clips and covers. The red clip must be connected to the conductor being
located, the black clip to a suitable ground such as the ground stake provided with the transmitter.
A good connection is indicated by a change in the beep rate from the speaker and the current reading on the display.
FUSE
Wherever a direct connection can be safely made without the risk of injury, damage to the customer’s plant, or the transmitter, it
is the best way of applying the transmitter’s signal.
The positioning of the ground connection can also influence the degree of coupling experienced. Ground connections generally
should not be made to other pipes or cables or above ground metallic structures such as wire fences. In general, the lower the
frequency is, the further the signal will travel, and the less signal-coupling will occur. The most common frequencies used for
direct connection are between 512Hz/640Hz and 8kHz.
Regulations in many countries require that power output is limited above specific frequencies. The Loc3 series 5-watt,10-
watt, and 25-watt transmitters enable frequencies below 45kHz to be transmitted using as much as 5-watts,10-watts or 25-
watt output, depending on your transmitter, but frequencies over 45kHz are restricted to 1-watt. Using direct connection and the
higher power at the low frequencies helps significantly in achieving greater location distances. Direct connections should not be
made to cables carrying greater than 25V (or as your safety practices allow). The transmitter is protected (250V fuse) from stray
currents that may exist on the target line.
