Operating instructions

187
Explosion proof fans
Data for flammable atmospheres / Classification / Ignition temperatures
■ Explosion proof to regulation
94/9/EC (ATEX)
■■
The European harmonized explo-
sion proof regulation (94/9/EC
ATEX) came into effect on 1st
July 2003.
■■
Explosion proof fans for operation
in or to move potentially hazar-
dous atmospheres or substances
must be in accordance with the
regulation 94/9/EC and have a
European Building Regulation ap-
proval and carry the CE marking.
■■
For that purpose the fans have a
classification (4).
■■
The fans are built in accordance
with VDMA 24169-1 "structural
explosion proof measures on fans".
■■
For certified data see motor
rating plate. A motor protection
device according to DIN EN
60079-0 / VDE 0170 / 0171 or
DIN EN 60079-10 / VDE 0165-
101, should be fitted to achieve
the required reaction
time t
E
.
■■
All relevant regulations must be
followed when making electrical
connections.
■■
Please enquire for models with
non-standard voltages, frequen-
cies and for flameproof models
to Ex d.
■ Zone definition, product group,
Product categories ➀
■■
Zone definition
Explosion proof zones will be
normally determined according to
the implementation of the
94/9/EC and operation reliability
regulation (if in doubt or for speci-
al applications, the local authori-
ties should be consulted).
Different zones have been alloca-
ted to take into account of the
different degrees of risk from the
concentration of flammable gas
or vapour may that arise in an
installation. It considers the
frequency and duration of the
hazardous atmosphere on each
occasion. Except for Mines (gas
group I below) six zones are
specified for 3 for gas (zones 0,
1 & 2) and 3 for dust (zones 20,
21 & 22).
■■
Product groups
Product group I: Products for
use in the underground part of
mines and those parts of surface
installations of such mines that
are likely to become endangered
by firedamp and/or combustible
dust.
Product group II: For use in
other places likely to become
hazardous by explosive atmos-
pheres.
Types of explosive gas group II
The explosive atmospheres are
either Gas vapour mist (G) or
Dust (D) and need one of the
following categories of protection;
1. Very high level of protection.
2. High level of protection.
3. Normal level of protection.
■■
Helios explosion proof fans are
suitable for product group II,
product category 2G or 3G for
operation in zone 1 or 2.
For specific classification see
catalogue or motor nameplate.
■ Enclosures (motors and termi-
nal boxes) types of protection
■■
classification: E Ex..
"e" – increased safety
"d" – flameproof enclosure
"de“ – flameproof enclosure
with increased safety
■■
Explosion groups for
enclosures ➁
I = electrical apparatus for mines
susceptible to firedamp
II = electrical apparatus for places
with a potentially explosive
atmosphere, other than mines
susceptible to firedamp.
Protection class "e" is in suitable
explosion group II and a "d" clas-
sification is required for explosion
group IIA, IIB and IIC.
■■
The degree of danger increases
from explosion group II A to II C.
If an apparatus is suitable for
group II B it can automatically be
used for group II A.
■ Ignition-, Surface temperature
and Temperature class ➁, ➂
■■
The ignition temperature is the
temperature at which an ignition
may occur e.g. through contact
with a hot motor surface. It de-
pends on the nature of the gases
and steams. The maximum sur-
face temperature of an electrical
appliance must always be lower
than the ignition temperature of
the substance used. (DIN EN
60079-0 or DIN EN 60079-10)
■■
The gases are divided into 6
different temperature classes
(T1-T6) with a decreasing ignition
temperature for higher class. The
gas will be put into the lowest
class where its ignition tempera-
ture is still higher than the one of
the temperature class. Apparatus
with a higher temperature (e.g.T5)
can also be used for substances
classified with a lower class (e.g.
T2 or T3).
■■
The temperature class, the maxi-
mum surface temperature and
ignition temperature are given in
table (2) in relation to specific
gas and table (3) for the ignition
temperature.
■■
The temperature class of each
fan is stated on the individual
catalogue page; for certified data
see motor rating plate.
■ Operation
■■
Explosion proof motors (protec-
tion "e" increased safety) do not
have thermal contacts.
Rectangular explosion proof fans
type KVD.. Ex, RD.. Ex and Axial/
VAR fans with high power are fit-
ted with PTC thermistors (positive
temperature coefficient).
■■
Speed control is permissible only
with rectangular explosion proof
fans (KVD..Ex, RD.. Ex) as shown.
Flammable material Ignition temperature Temperature class Apparatus group
°
C
Acetaldehyde 155 T 4 II A
Acetone 535 T 1 II A
Acetylene 305 T 2 II C
Ethane 515 T 1 II A
E
thyl acetate 470 T 1 II A
E
thyl ether 175 T 4 II B
Ethyl alcohol 400 T 2 II B
Ethyl chloride 510 T 1 II A
Ethylene 440 T 2 II B
Ethylene oxid 435 T 2 II B
dissociate
Ethyl glykole 235 T 3 II B
Ammonia 630 T 1 II A
i-Amylacetate 380 T 2 II A
Petrol 220 to 300 T 3 II A
Boiling point< 135°C
Special petrol 220 to 300 T 3 II A
Boiling point > 135°C
Benzene (pure) 555 T 1 II A
n-Butane 365 T 2 II A
n-Butyl alcohol 325 T 2 II B
Cyclohexanone 430 T 2 II A
1,2-Dichlorethane 440 T 2 II A
Diesel 220 to 300 T 3 II A
DIN 51601/04.78
Nozzles fuels 220 to 300 T 3 II A
Acetic acid 485 T 1 II A
Acetic acid anhydride 330 T 2 II A
Aviation fuel EL 220 to 300 T 3 II A
DIN 51603 Part 1/12.81
Aviation fuel L 220 to 300 T 3 II A
DIN 51603 Part 2/10.76
Aviation fuel M and S 220 to 300 T 3 II A
DIN 51603 Part 2/10.76
n-Hexane 230 T 3 II A
Carbon monoxid 605 T 1 II A
Methane 595 T 1 II A
Methanol 440 T 2 II A
Methyl chloride 625 T 1 II A
Naphthalene 540 T 1 II A
Oleic acid 250 T3 –•)
dissociate
Phenol 595 T 1 II A
Propene 470 T 1 II A
n-Propyl alcohol 385 T 2 II B
Carbon disufilde 95 T 6 II C
Hydrogen sulfide 270 T 3 II B
Town gas 560 T1 II B
Tetralene 390 T 2 –•)
(Tetrahydronaphthalene)
Toluene 535 T 1 II A
Hydrogen 560 T 1 II C
➂ Ignition temperature
*
Extract from “Selection, installation and maintenance of electrical apparatus for use in potentially explosive
atmospheres” PTB Braunschweig, E. Brandes/W. Möller. ISBN 3-89701-745-8
–•) For this substance an explosion group has not yet been determined
➁ Data for flammable materials for use with electrical equipment
T 1 450 °C > 450 °C
T 2 300 °C > 300 °C
T 3 200 °C > 200 °C
T 4 135 °C > 135 °C
T 5 100 °C > 100 °C
T 6 85 °C > 85 °C
Temp. Maximum Ignition temp.
class surface temperature of flammable
of machine substance
➃ Classification
II 2G EEx e / de II / IIB T3
Product group
Product category
Expl. proof protection to EN
Type of protection
„ e = increased safety“
„ de = flammable enclosure
with increased safety“
Gas group / sub group
Temperature class
➀ Zone definition, product group, product categories
Flammable
Zones to
Description
Product-
Product-
substances
DIN EN 60079-10 group category
G
ases,
v
apour,
f
og
Dust
Zone 0 Zone in which an explosive atmosphere is II 1G
c
ontinuously present, or present for long
periods.
Zone 1 Zone in which an explosive atmosphere is II 1G
l
ikely to occur in normal operation. or
2G
Z
one 2 Zone in which an explosive atmosphere is II 3G, 2G
not likely to occur in normal operation, and or 1G
i
f it occurs it will exist only for a short time.
Zone 20 Zone in which an explosive atmosphere is con- II 1D
t
inuously present, or present for long periods.
Zone 21 Zone in which an explosive atmosphere is II 2D or
l
ikely to occur for a short period due to the 1D
presence of dust in the atmosphere.
Z
one 22 Zone in which an explosive atmosphere in the II 3D
form of a cloud of combustible dust in air is
not likely to occur in normal operation, and if
it occurs it will exist only for a short time.