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Scope
When it is intended to work on any Electrical Power Cable,
either for the purpose of carrying out repairs or for
tapping or arranging additional feeders, it is vital that
special precautions be taken to secure the safety of the
employees. After the cable has been made dead and connected
to earth at the point of supply, the cable is cut, usually
by means of hacksaw or cutters.
Criteria
It often happens that the cable to be cut is distant from
the circuit disconnect, grouped with other cables and
sometimes buried in the ground. In order to avoid any
possibility of a mistake and a "live" cable being cut, most
authorities insist that a sequential rigid four step
procedure be followed which requires the disconnection of
power at both circuit ends, identification of cable markers,
electronic instrumentation signal checks and finally cable
mechanical spiking. The authorities made the final step
mandatory which requires that a wide iron spike be driven,
either with a hammer or an extended stick into the cable
intended to be cut before allowing further work to proceed.
If by any mischance a "live" cable is spiked, the resulting
high magnitude short circuit current should trip out the
feeder circuit breaker.
Safety Considerations
This method was somewhat crude and there is grave danger to
the employee carrying out the spiking operation, owing to
the sudden thrust of substantial electrical fault energy
capable of exploding the cable and creating a high velocity
deadly spray of conductor, shield and or sheath metal
fragments. Even the sight of a fault flashover could cause
permanent blindness.
Safety Features
In order to enable the spiking operation to be carried out
in perfect safety, the ACCLES & SHELVOKE CABLE SPIKER cable
spiking gun has the great advantage that it can be remotely
controlled at the moment of firing by means of a lanyard
(rope) release. The operator can thus stand at a point of
safety and if by chance a "live" cable is spiked, the damage
will be local to the cable. As the speed of penetration of
the spiking punch is so rapid, it has been found in practice
that even if a " live" cable is spiked, usually no damage to
the cable spiker results. If however, the fault current
happens to be extremely high, it may be that the actual
spiking punch itself may suffer, but yet be capable of
tripping a normally operating breaker. This punch, is of
course, easily replaceable and a spa re ca n be fitted i n a
matter of seconds. An added feature of the ACCLES & SHELVOKE
CABLE SPIKER is that the wide punch shears the cable
partially or totally, depending on the cable size, hence
reducing additional cable cutting effort.
Applications
The Accles & Shelvoke Cable Spiker is suitable for use with
all types and voltages of power cable including single and
multiple conductor laminated, polymeric, elastomeric,
unshielded, shielded, concentric neutral, interlock
armoured, steel wire armoured, leaded covered etc., designs
in either fixed or portable installations.
Prevents Accidents
The Accles & Shelvoke Cable Spiker is a quality durable tool
designed to positively electrically ground out any required
power cable for definite manpower accident prevention and
life saving. |
