Electricity + Control January 2017

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Optimal surge protection for wind turbines with DFIG systems
2015 saw a huge boost for the wind industry, with annual installa-
tions surpassing 60 GW for the first time in history. At the end of
last year, the new global total amounted to 432,9 GW, denoting a
cumulative market growth of more than 17%.
This unprecedented growth has led to an increased concern around
the lighting and surge protection of wind turbines, a concern that
is addressed by the introduction of DEHNguard DG SE H 1000 VA
FM surge protector, specifically designed to minimise the risk of
failure resulting from surges when it comes to wind turbines with
doubly-fed induction generator (DFIG) systems.
This powerful new arrester is rated for voltages up to 1 000V and
discharges currents up to 40 kA (8/20 µs). Its module locking system
ensures that neither shock nor vibration during transportation and
use, or even an enormous force of discharge, can loosen the protec-
tion modules.The protection modules can also easily be replaced
- without tools - by simply pressing the module release button.
DEHNguard SE H 1000 VA FM is ideally suited for wind turbines
(with DFIG-Double Fed Induction Generator), however it can also be
used for other applications with up to 100 V, such as, photovoltaic
(PV) systems, railways systems, industrial plants and cable cars.
Enquiries: Kirk Risch.Tel. +27 11 704 1487 or
email
Installation testing protects appliances, wirelessly shares data
Growing concern for public safety and the increasing complexity
of today’s fixed electrical installations in domestic, commercial
and industrial premises places extra responsibility on electrical
test engineers who are charged with verifying conformity to South
Africa’s Certificate of Compliance (COC) safety standards.
SouthAfrica’s electrical contractors are well versed in the verifica-
tion requirements of the COC, and that the audit should be carried
out in the following sequence:
• Visual inspection
• Testing of the following:
* Continuity of protective conductors
* Insulation resistance
* Protection by separation of circuits
* Floor and wall resistance
* Automatic disconnection of supply
* Polarity
* Functional performance
In addition to this the following tests are under consideration:
• Electric strength test;
• Voltage drop.
The basic requirements for test equipment used in installation test-
ing consists of general requirements for test equipment, specific
requirements for combined measuring equipment and the specific
requirements for measuring/testing:
• Insulation resistance
• Loop impedance
• Resistance of the earth connection
• Resistance to earth
• RCD performance in TT and TN systems
• Phase sequence
• Insulation monitoring devices for IT systems
Available from Comtest, the Fluke 1660 Series Multifunction Instal-
lationTesters are measuring equipment which fully fulfil the require-
ments as described above, and the three different models in the
series comply with specific parts of this norm.They are specifically
designed to carry out the tests specified, and all local standards
and regulations in the safest and most efficient way.
Enquiries: Comtest.Tel. +27 (0) 10 595 1821 or
email
Introducing arc protection system to local market
DEHN Africa recently launched its DEHN-
short arc fault protection system to the local
market, with an intensive training session
held at its Johannesburg office.
Overseen byAndreas Schumacher, Prod-
uct Manager: Safety Equipment/ Arc Fault
Protection from DEHN + SÖHNE, DEHN
Africa sales engineer, Tatenda Gora, con-
ducted the training which was entitled:The
Introduction of DEHNshort to South Africa
- protection through detection for arc faults
in low voltage switchgear assemblies.
The training session covered topics
including a description of arc faults; the
standards and norms of arc fault protec-
tion; an introduction to the DEHNshort
product and its application; as well as a
demonstration of the new product offering.
The comprehensive training was aimed
both at DEHN Africa staff and partners as
well as local clients.
Enquiries: Kirk Risch.Tel. +27 (0) 11 704 1487
or email
EARTHING + LIGHTNING PROTECTION ROUND UP
Electricity+Control January ‘17 28