Besantek BST-GFL31, User Manual

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BST-GFL31 User Manual
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1.7.3 Short circuit
One power system generally comes with several loads working together at the same time. Normally
when all loads are disconnected, power output current becomes O Amps. However, when insulating
values of one point or more are lower than requirement but there is still current flow, we call it as “short
circuit”. In this case, positive busbar is short-circuited to negative busbar.
Short circuit will increase power consumption and may even burn up power supply and cause other bad
accidents like faulty grounding.
1.7.4 Current leakage
Circuits, which are normally insulated to the ground, have current flow to the ground due to bad
insulation or circuit distributing capacitance.
1.7.5 Tracing of Current Signal
When we are using the BST-GFL31 to locate the faulty grounding, signal generator (main unit) will send
a “current signal” in certain frequency to the circuit. This current signal will flow in the circuit. With a
signal receiver (connected with a current detector), we will trace the current signal in different points of
the circuit. In comprehensive ways of signal judgment like current direction, signal strength and phase
angle, we will fast locate the ground fault.
For detailed ways to pinpoint the faulty grounding, we will introduce in Chapter 2 below.
2. MAIN OPERATION OF BST-GFL31
2.1 General Steps for Fault Location
For ground fault location, we will generally follow these steps:
1) Measurement preparation
Familiarize with the wiring structure of DC system and judge which line has faulty grounding.
It is very important to know the wiring structure on how the wires are connected in the DC system.
This will help you fast trace the ground fault.
2) Connect the signal generator with DC system.
When positive busbar has ground fault, connect red testing lead with positive busbar and black lead
with ground. When negative busbar has fault, connect black lead with negative and red lead with
ground.
3) Set output signal in signal generator and set signal mode as “Continue”.
Signal generator will test output voltage, current and grounding resistance.
4) Do frequency synchronization in receiver
5) Proceed with “Reference setting” in signal receiver
6) Follow the theory of ground fault location to pinpoint the faulty grounding one by one.
7) Make a record for the signal strength for each branch for signal comparison afterwards. If necessary,
set the reference several times for better comparison.
8) Solve the problem of faulty grounding as per requirement.
Here, we will explain deeper for each step.