sparks
ELECTRICAL NEWS
june 2014
contractors’ corner
7
LEGRAND’S extensive range of products and
systems for electrical installations and building
infrastructures, encompasses environmentally
friendly cast resin transformers, designed for low
environmental impact.
“Legrand’s energy efficient cast resin transform-
ers, which efficiently transfer electrical power
between two different voltage systems, at the
same frequency, are manufactured by a Legrand
subsidiary, EdM, according to stringent quality
and safety specifications,”says Luk Ivens, general
of vibrations between core and windings, also
reducing operating noise levels and absorbing
thermal expansion of components. Sockets on
the MV side adapt the primary voltage to the
mains, which can be set with the transformer
switched off.
Class F insulatingmaterial, at 155°C allows for
a temperature rise of 100°C and the epoxy resin
insulationmeans lowmaintenance. The carriage
of these units, which allow safe movement, is
pre-equipped for the mounting of IP reinforced
enclosures. Accessories include thermal sensors
or thermistors, electronic units for temperature
control and forced ventilation systems to increase
transformer power in temporary overloads or at
high environmental temperatures.
Legrand can also supply MV terminations for
plug-in
connections, surge arrester kits and anti-vibrating
supports. Protective enclosures, available with
different degrees of protection – IP21, IP31
and IP23 – protect transformers from external
environmental impacts and people from the risk
of direct contact. EdM transformers are enhanced
by the Zucchini busbar trunking systemwhich
provides synergy for a direct connection. These
busbars are available in aluminiumor copper.
Legrand offers a technical advisory service on
which transformer and busbar trunking system
provides the best solution for every specific ap-
plication in the distribution of electrical power,
energy co-generation, rectification and traction.
Enquiries: (011) 444-7971
manager, Legrand Southern Africa.“These
transformers have no risk of insulating fluid
losses and are a low fire hazard – even in
harsh environments, like on the mines and in
chemical and petrochemical plants.
“Other advantages of these transformers
are significant savings on electricity costs and
minimal energy waste. This compact system
has also been designed for easy installation
and lowmaintenance requirements – no oil
changes are necessary.
“The absence of flammable insulation
liquids, the use of self-extinguishingmaterials
exempt of toxic gas emissions, reduced noise
levels and low electromagnetic emissions,
ensure enhanced environmental protection
in all sectors.”
Legrand’s standard distribution transform-
ers have rated power between 100 and
3 150kVA, primary rated voltage up to 36kV
and secondary rated voltage up to 433V.
Special transformers have rated power up to
17 000kVA.
Unlike oil transformers, these cast resin
units, with reduced overall size dimensions,
can be installed inside buildings and do not
require additional building structures. This
means optimum flexibility in any installa-
tion. Because no cooling fluids are necessary,
maintenance costs are alsominimised.
These transformers have features for
enhanced efficiency and optimum safety.
Rubber inserts alleviate the transmission
Environmentally friendly cast resin transformers
THE MB relay is ISO 9001:2000 compliant and fea-
tures starter logic and logic function blocks which,
coupled with its multi protocol communication
options, make it an ideal solution for plant automa-
tion. All configurable inputs have 73 possibilities
that include alarm and trip flags, timers, function
block and RTC outputs, digital field and PLC inputs.
The MB relay is fully configurable with the aid of
free front-end software or a man-machine-interface
unit (MMI). Up to 1 440 event records can be date
and time stamped and downloaded and viewed in
MS Excel. Essential statistical data ensures infor-
mation retrieved from the relay can be used for
maintenance purposes before drive failure. The
three-phase recorder allows the user to recordmo-
tor currents, voltages, thermal capacity and power
factor which can be monitored and analysed in real
time. This is particularly useful when tripping occurs
for no obvious reason.
Plugged into the basic unit, the expansion
module caters for Profibus DPV 1, Modbus RTU
and CANbus communicationmodules. The base
unit comes complete with an integrated CTMB and
CBCT current measurement range from 0.5 to 250A.
The relay is fitted with seven field inputs and four
relay outputs with individual fault and I/O status
indicating LEDs.
Enquiries: (012) 327-1729
Protection relay for
plant automation
