Feb. 20, 2020
As a Rubber Cable Factory, share with you. During long-term use, power cables
will inevitably fail due to various reasons. Affects the smooth production of
the enterprise, so it is of great significance to be able to quickly
troubleshoot and restore normal power supply.
1. Common faults and causes of power cables
Common faults of power cables include poor conduction, poor insulation, short
circuits, and open circuit faults.
The cause of poor electrical conductivity is generally that the cable
terminals are not tightly connected, resulting in increased contact
The causes of poor insulation and short-circuit faults are generally the
cable's own insulation materials and manufacturing process defects; the cable
head insulation materials, manufacturing process defects, and construction
methods are not correct; the insulation is dampened, aged and deteriorated; and
it is caused by long-term overvoltage.
Open circuit faults are generally caused by external mechanical damage.
Basically, cable failures are caused by poor insulation or damaged
insulation. Usually, the fault can be solved as long as the damaged insulation
is restored, so the detection and confirmation of the fault point of the cable
is the key to solving the problem.
Rubber Cable (IEC)
2. Commonly used Rubber Cable fault detection methods
At present, the detection of power cable fault points is usually measured by
the bridge method, low-voltage pulse reflection method, pulse current method,
two (multiple) pulse method, and acousto-magnetic method.
Short-circuit the faulty phase of the tested cable with the faulty phase. The
two arms of the bridge borrow the faulty phase and the non-faulty phase, adjust
the resistance to balance the bridge, and then use the formula to calculate the
location of the fault point. Its characteristics are simple. Convenient and
Low voltage pulse reflection method
During the test, a low-voltage pulse is applied to the faulty phase of the
cable. When the pulse propagates along the cable to the impedance mismatch
point, the pulse reflection will be sent to the test point. According to the
time difference between the transmitted and reflected pulses and the wave
velocity of the pulse in the cable , You can calculate the location of the fault
Pulse current method
Use high-voltage pulses to click through the cable fault, collect and record
the pulse current waveform after the fault click through the meter, find the
distance between the primary and secondary reflected pulses of the fault point,
and locate the cable fault point.
Two (multiple) pulse method
A low voltage pulse is transmitted to the faulty cable and the waveform is
recorded. Then a high voltage pulse is transmitted to the faulty cable to click
through the fault, and a low voltage pulse is transmitted again, and the low
voltage pulse is reflected back at the breakdown point. The waveforms of the two
low-voltage pulses are superimposed, and the intersection point is the location
of the fault point.
Our company also has Rubber Cable (IEC) on sale, welcome to consult.