Cover story
Enhanced fire protection through state-of-the-art technology
Cause of Fire Switched
Off Intelligently
Well protected from electrically
induced fires with the 5SM6
arc fault detection device
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E-Installation | 01-2012
The planning, selection, construction, and operation
of electrical installations always includes protection
from hazardous incidents. The 5SM6 arc fault
detection device uses state-of-the-art technology
to set a new standard for reliable protection from
fires caused by electricity.
ever, they are not capable of detecting
serial arcing faults in particular, so
complete protection is not provided.
Accidental arcing caused by a fault in
the electrical system will not necessarily
have dire consequences, but electric
arcs can very quickly lead to high temperatures, particularly at the source. If
this heat comes into contact with highly
flammable material in the immediate
environment, a fire can quickly start –
with grave consequences for people, the
electrical system, and the building.
The 5SM6 arc fault detection device
(AFDD) can now reliably close this gap
in the protection of an electrical system. In this way, the DIN VDE 0100-100
requirement is fulfilled: the risk of ignition of flammable materials due to high
temperatures or as a consequence of an
electric arc is minimized. The switch
reliably differentiates between normal
operational arcing faults and hazardous
arcing faults.
Introduction of proven technology
to the IEC market
Arcing fault detection equipment has
been mandated for years in North
America by NEC 2008, and such equipment is used widely: as arc fault circuit
interrupters (AFCIs) for serial faults; as
a combination of MCBs and AFCIs for
parallel faults, phase-neutral or phasephase; or as a combination of a ground
fault circuit interrupters (GFCIs) and
AFCIs for parallel faults, phase-ground.
Protection in the event of serial arcing
faults was previously not covered in the
European (IEC) market. From a technological
standpoint, AFCIs from Siemens
Protection of the electrical
offered
the ideal basis for further develinstallation now gap-free
opment. The first patents for AFCI techThe circuits in the electrical installation nology were already registered in 1983.
are normally protected with miniature The first AFCI generation protected
circuit breakers (MCBs) and residual against parallel electric arcs with a tripcurrent circuit breakers (RCCBs). How- ping threshold of ≥ 75 A (according to
E-Installation | 01-2012
gettyimages / Ivan Hunter
A
n apartment is destroyed by fire –
caused by a technical defect in a
household electrical appliance, by
a ruptured extension cord, or by an
expansion of the electrical installation
by a non-electrician. In a hospital, a fire
led to total damage of almost €3 million;
the cause was a damaged incoming electrical cable. The list of damage claims
such as these is long and alarming.
In Germany alone, a quarter of all
recorded fires are blamed on dangerous
deficiencies in the electrical installation.
In addition to material damage in the
billions, there are also many injuries
and even fatalities.
Even in modern electrical installations with a low fire load, electrical
cables and terminal devices still pose a
fire risk. At the top of the list of these
fire causes are what are known as internal or arcing faults. They can be triggered in the electrical installation when
cable insulation is mechanically damaged or when terminal devices are
defective – because a contact has
become loose or detached, for example.
But careless conduct in an existing functional electrical installation can also
quickly lead to hazardous situations:
cables or plugs are crushed, or electric
terminal devices are subjected to heat
and/or humidity. Among the causes of
fire compiled from the damage database
of Germany’s Public Insurers’ Institute
for Damage Prevention and Damage
Research, clothes dryers, televisions,
refrigerators, freezers, dishwashers,
and washing machines are at the top of
the list.
5
Cover story
UL 1699). The new AFCI generation pro- units, or fluorescent lamps; or when
tects against parallel and serial electric electric arcs occur in neighboring cirarcs with a tripping threshold of ≥ 5 A cuits, causing cross talk to occur.
(according to UL 1699). This greatly
increases fire protection, with a high Comprehensive protection concept
degree of resistance to unnecessary for every electrical installation
tripping. With the 5SM6, Siemens is
currently introducing this technology The 5SM6 AFDDs are recommended
to the IEC market as an AFDD, assuming both for new installations and for exista pioneering role here. After extensive ing and older systems, with older eleclaboratory and field trials to test the trical installations in particular posing
complex detection of the right electric a higher potential of hazardous arcing
arcs, comprehensive protection can faults. Depending on the design of the
now be assured. Unwanted tripping electrical installation, 5SM6 AFDDs are
due to normal operational interference combined with an MCB or an RC/MCB
sources is prevented. The 5SM6 AFDD is from the established portfolio in order
not tripped by starting current for fluo- to provide the greatest possible protecrescent lamps or capacitors; in case of tion. In conjunction with an upstream
electric arcs on electric motors, thermo- RCCB, the combination with the MCB is
stat contacts, or light or device plugs; in used; in all other applications the comcase of sinusoidal oscillations of elec- bination with the RC/MCB. In case of
tronic lamp dimmers, power supply residual current, overload, short circuit,
Closing of the safety gap in the IEC market with UL-proven technology
Type of fault
Serial
Protection according to IEC standard
Protection according to UL standard
New
L
LOAD
AFDD
AFCI
N
Parallel
phase-neutral/
phase-phase
New
L
LOAD
MCB
AFDD
MCB
AFCI
RCD
AFCI
N
Parallel
phase-protective
conductor
New
L
LOAD
RCD
AFDD
N
AFDD
MCB
RCD
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E-Installation | 01-2012
Arc fault detection device
Miniature circuit breaker
Residual current protective
device
AFCI
MCB
RCD
Arc fault circuit interrupter
Miniature circuit breaker
Residual current protective
device
Highlights
Closes the previous gap in
protection with high-quality,
proven technology
+
Can be used in a wide variety
of residential and
nonresidential buildings for
comprehensive fire protection,
both in new installations and in
existing systems
+
Reliable tripping of electrical
circuits when hazardous arc
faults occur
+
Fast and safe installation
or arcing fault, the secured electrical
circuit is then disconnected from the
power supply system on all poles.
Both device versions can be used in a
variety of combinations, with various
MCBs in the versions 1+N in 1TE or 2TE,
or with RC/MCBs up to 16 A of rated current, and can be easily integrated into
any distribution board. That makes the
product selection as easy as the installation. In any combination with a diverse
array of additional components of
MCBs or RC/MCBs, it is possible to connect to a higher-level control system
using a retrofittable auxiliary contact so
that a message is sent to a central control room when the circuit breaker trips,
for example. The 5SM6 AFDD can be
quickly plugged into a desired combination without tools and simply clamped
onto the standard mounting rail. Power
can be quickly and safely supplied
through infeed from a busbar.
When used in the appropriate installation concept, 5SM6 AFDDs offer the
highest level of quality and reliability
for unique protection in residential and
+
nonresidential buildings.
The comprehensive
protection concept
offers the highest
level of safety for
all buildings
Fotolia / Aleksandr Ugorenkov
+
+www.siemens.com/lowvoltage
CONTACT:
+support.automation@siemens.com
Siemens AG
LINK TO THIS TOPIC:
The 5SM6 arc fault
detection device can be
used in combination
with a miniature circuit
breaker (left) or a
residual-current circuit
breaker with overload
protection
E-Installation | 01-2012
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