Atec Megger-BGFT - Manual

BGFT
Battery Ground Fault Tracer
I Easily locates ground faults in
ungrounded dc systems
I Operates in high electrical noise
environment
I Simplifies fault tracing by identifying
fault characteristic (resistive and
capacitive) magnitudes
BGFT
BATTERY GROUND FAULT TRACER
DESCRIPTION
The Battery Ground Fault Tracer is an economical, easy-to-
use instrument that identifies, traces and locates ground
faults in ungrounded dc systems — on-line. It is
particularly effective in high electrical noise environments,
as the strength of the test signal can be adjusted.
The Battery Ground Fault Tracer accelerates fault location
by eliminating trial-and-error procedures and because
faults can be located without going off-line. It is
particularly useful in any industry where supply of power
for operating measurement, communication and control
equipment is critical.
APPLICATIONS
The Battery Ground Fault Tracer, which consists of a line-
operated transmitter and a portable, battery-powered
receiver, determines fault magnitude and severity. The
transmitter connects to the battery bus and station ground.
Incorporating a resistance and capacitance bridge, the
transmitter can be used to determine the fault’s magnitude
and severity prior to tracking the fault.
System capacitance can then be nulled from the
measurement to prevent erroneous readings on the
receiver. Immune to distributed noise in the system,
Battery Ground Fault Tracer readings are unaffected by the
presence of dc current and ac ripple up to 15 Amperes.
The transmitter can be left behind during tracing, which is
performed quickly and easily using the hand-held receiver
and clamp-on probe. The receiver provides digital display
of signal amplitude, with a multiposition switch to adjust
gain for optimal display resolution.
PRINCIPLE OF OPERATION
The Battery Ground Fault Tracer transmits a 20 Hz signal
through an energized or de-energized dc system. Feeder
cables are tested for signal amplitude, which is inversely
proportional to the fault impedance. Faults up to 100 k
Ω
are easily traced and isolated by clamping a direction-
sensitive probe on the feeder cable and monitoring signal
strength on the hand-held receiver.
FEATURES AND BENEFITS
I Digital display of voltage and current signal amplitudes
I Bridge measurement of fault resistance and system
capacitance. (The use of the bridge is optional.)
I Wide fault resistance measurement range from 1 k
Ω
to 399 k
Ω
I Immune to distributed noise
I Soft-start charging system to prevent sensitive relay
tripping
I Convenient, hand-held receiver
I Receiver gain control for optimal display resolution