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Basic Function and Design
The CHANCE® Auto-Ranging Voltage Indicator (“ARVI”) is a portable tool to
confirm that a high-voltage line is de-energized prior to performing mainte-
nance. It presents field practicality over a voltmeter and obvious advantages
over traditional methods without a meter. Readings from the ARVI represent the
class of voltage that is present on the line.
The C403-3374 is designed to determine phase-to-phase voltage classes up to
69kV. The C403-3375 is designed to determine phase-to-phase voltage classes up
to 500kV. Both units consist of one section of Epoxiglas
®
pole with high internal
impedance that is encapsulated to prevent moisture penetration and mechanical
damage.
The ARVI is actually an electric field intensity meter, which is calibrated to
illuminate an LED (light-emitting diode) representing the class of voltage that
is present on the conductor. It responds to the magnitude of the field gradient
between its end probe and a floating electrode. The device indicates the combined
field intensity from all other conductors, including ground wires and grounded
equipment. If the universal fitting is close to a ground, another phase, or another
voltage source the voltage indication will tend to be high. If the universal fitting
is close to a jumper or equipment of the same phase, the indication will tend to
be low. The tool must be used with a universal pole to maintain its calibration.
The ARVI can be used as a secondary means to confirm the condition of a circuit
after principal work procedures such as visible open gaps, dispatcher hold
orders, and apparatus tag-outs have rendered the circuit de-energized.
Operation — General
To turn the unit on press and release the “Power” push button. Upon power-up
each LED will illuminate individually from the lowest voltage to the highest
followed by the audible alarm. These tests verify the function of the LED’s,
alarm, batteries, and internal circuitry. Full unit function can only be verified
using a known energized high voltage source or with the appropriate Voltage
Indicator Tester (C403-3409 for C403-3374 ARVI and C403-3431 Voltage Indi-
cator Tester for C403-3375 ARVI). Following the audible alarm the “Power / Low-
Battery” LED will flash indicating that the unit is ready for use. After use turn
the unit off by holding the power switch until the power LED turns off, or the unit
will power itself down after approximately 15 minutes of inactivity.
The unit will begin to make an audible beep and an LED will blink when the unit
senses an electric field, even when not making contact with an energized
conductor. The higher the voltage, the faster the beeping occurs. If the unit
senses constant voltage for approximately 15 seconds, it automatically goes into
its hold-mode. At that point the LED representing the voltage class being
indicated will light continuously and the beeping will become continuous for 1 to
2 seconds followed by 5 to 6 very rapid beeps and a brief period of silence. The unit
then will return to the normal audible mode, but one LED will remain solid until
reset. Remove the unit from the line and press and release the power switch to
reset the unit.
Once in the Auto-Hold mode, the ARVI must be reset for the LED's to indicate higher
or lower voltages.
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CAUTION
