Operation; Preparation For Use; Limitations On The Model 275Hvd - AEMC 275HVD Manual De Instrucciones

4.1

Preparation for Use

The Non-Contact High Voltage Detector should be inspected for any visible
signs of damage before using, battery condition and the checks described
below should be performed to ensure that it is operating correctly.
When you first receive it, if there is any sign of damage or if the instrument
does not operate correctly, return it to the distributor from which it was
purchased.
4.2

Limitations on the Model 275HVD

See Warning on Page 5 & 6
• Testing voltages on cable composed of multiple phases may be a prob-
lem. In particular, multiple phase cables twisted together may have
their electrical fields canceling each other out (vector sum), and a much
lower detectable field signal may result. This may lead to non-detection
if the range setting is too high. Try a lower range setting if this situa-
tion occurs. Keep in mind that the actual line voltage may be much
higher!
• Problems can arise when the 3-phase circuit of a 275/133/11kV trans-
formers are tested. The electric field of the HV and MV bus bars can
trigger the detector when it is about one meter (approx 3 ft) above the
ground. Users must be aware that this is common with most of the
electric field voltage detectors. The 275HVD can pick up adjacent cir-
cuit electrical fields to the one being tested and may indicate the wrong
information to the user.
• Electrical Field sensitivity is reduced when the 275HVD is used close
to grounding points.
• The Model 275HVD will work on cables with a concentric neutral.
• The Model 275HVD will not work on shielded cables.
Non-Contact, High Voltage Detector 275HVD
CHAPTER 4

OPERATION

11