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Electric Energy T&D - Index

Electric Energy T&D - EE Magazine March / April - Index

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New Outdoor Circuit Breaker
offers Simplified Design with
Magnetic Actuators
AREVA T&D (Transmission & Distribution)
introduced EOX MAGnetic ™ , the company’s
new line of vacuum outdoor circuit breakers
with magnetic actuators in the North
American market at DistribuTECH 008
Conference & Exhibition in Tampa, FL, January
- 4, 008.
Available in ratings up to 15.5kV, 000A,
5kA, the EOX MAGnetic uses a magnetic
actuator to operate the circuit breaker. EOX
MAGnetic has an improved design with
Circle 29 on Reader Service Card
decreased number of moving parts and
requires no adjustments or lubrication at
site. Rated for switching capacitive currents
up to 1 00A, EOX MAGnetic has been tested
according to IEC and ANSI standards for
100,000 mechanical operations. Due to its
simpler design and reduced number of moving
parts, this breaker is virtually maintenancefree
after its initial inspection.
18 I March-April 2008 Issue
How it works
Actuators utilise the force generated by a
magnetic flux in a circuit to operate the
contacts of interrupters. In this design, the
actuator stays in the closed position due to
the permanent magnets and remains in open
position by the force of the opening springs.
A single coil provides close and trip actions
depending on the direction of the injected
current. The required opening speed is reached
with the help of the opening springs.
The actuator is composed of a metallic
armature (or core), one coil, a mobile plunger
(or yoke) going through the coil and permanent
magnets. Coils are energised by the discharge
of a capacitor through the controller. The
main function of the controller is to ensure
the charge or the discharge of capacitors (or
batteries) in the actuator coils when receiving
an opening or a closing order. Monitoring and
communications are via an integrated circuit.
This specific controller is used for the French
TGV railway switch application.
caption for Image: AREVA T&D’s new
breaker features a “T” shaped plunger which
increases the latching force of the actuator by
controlling the magnetic flux. The two surfaces
corresponding to the edges of the “T” intersect
the flux path. The yellow arrows show the
magnetic force. Consequently, the “T” plunger
allows reducing the size of the actuator. The
new actuator operates like a contactor with
the specific requirements of a circuit breaker.
circle 66 on Reader Service card
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High Voltage Test Expert, Phenix
Technologies Introduce 100 kV
Portable AC Hipot
The 6CP100-7.5 is the first in a new series of
AC Dielectric Test Sets developed by Phenix
Technologies offering higher current levels
with portable AC Hipot equipment.
The equipment has a unique circuit built
into the input of the test set with switchable
capacitive compensation which allows for
7.5 kVA output power with 3.3 kVA of input
power. “This feature gives the unit a broader
range of test applications while maintaining
the portability of the equipment”, states
Phenix rep.