VSD AND SS
DRIVING ATEX MOTORS
February 2014
1
Introduction to ATEX
2
ATEX motor designation
3
VSD Sample Solutions
4
SS descriptions
Introduction to ATEX
EU territory define the use of electrical equipment in potentially explosive atmospheres,
within the directives 1992/92/EC and 94/9/EC.
 1992/92/EC (ATEX 137) covers the minimum requirements for improving the health and
safety protection of workers operating in potentially explosive atmospheres.
 94/9/EC (ATEX 95) is intend to allow free trading of equipment and systems for use in a
hazardous area without the need for separate testing and documentation.
ATEX 95
ATEX 137
Product Directive
94/9/EC
Requirements and
certifificates for manufacturers
Workers Protection DIrective
1999/92/EC
Classifies zones and states the
corresponding product category
*EHSRs
Zones
Product Requirements
* Essential health and safety requirements
 Category 1
 Zone 0/20
 Category 2
 Zone 1/21
 Category 3
 Zone 2/22
Risk analysis
Introduction to ATEX
CENELEC / IEC Standards provide a criteria which determine the classification of the
equipment into groups and categories according to EN / IEC 60079-0:
Depending on the intended use, explosion proof electrical operating equipment is divided
into two major groups:
 Group I: Equipment for coal mines (only special designed motors for mines can be used)
 Group II: Electrical equipment for use other than mines (surface industry)
GROUP I ( MINES)
DESCRIPTION
Equipment designed to operate on environments where the
explosive atmosphere is present frequently
Equipment that must be powered off if there is any risk of
explosion. Explosive atmosphere is present frequently.
CAT
M1
M2
GROUP II ( SURFACE INDUSTRY)
CAT
1
2
3
GRUPO
IIA
DESCRIPTION
Equipment with high degree of protection. Explosive
atmosphere is present continuously or for long periods
of time.
Equipment with high degree of protection. Explosive
atmosphere may occur occasionally..
Equipment with normal degree of protection. The
explosive atmosphere will probably not occur.
LABEL
ZONE
1G (gas)
1D (dust)
0 (gas)
20 (dust)
2G (gas)
2D (dust)
1 (gas)
21 (dust)
3G (gas)
3D (dust)
2 (gas)
22 (dust)
SUB-GROUP CLASSIFICATION FOR GASES OF EXPLOSURE ATMOSPHERES ( FLAME PROOF MOTORS)
DESCRIPTION
Acetone, ammonia, benzene, butane, butanol, alcohol butylic, ethane, ethanol, acetate of ethyl, gasoline, hepthanes, hexanes, natural gas, methanol,
naphtha, propane, propanol, toluene, esthirene, solvents in general
IIB
Acetaldeide, cyclopropane, diethylic ether, ethene, monoxide of carbon
IIC
Acetylene, butadiene, oxide of ethene, hydrogen, oxide ofpropylene, gases containing over 30% of hydrogen
ATEX MOTOR DESIGNATION AND AREAS
MOTOR DESIGNATION
TYPE
DESCRIPTION
tD/DIP
Protection by dust ignition prove
enclosure according to IEC
61241-1
nA
Not sparking. Increased safety
in terminal box.
d
Explosion Proof (Rugged frame)
de
Explosion Proof with
Increased Safety Terminal Box
e
Increased Safety. Increased
safety in terminal box.
p
Pressurized. (Special
construction)
CLASSES OF TEMPERATURE
The minimum temperature that causes an explosion of a gas, vapour of explosive mixture is
called ignition temperature. To avoid any risk of explosion, the motor surface temperature must
always stay below the ignition temperature of the explosive mixture.
Class of Temperature (ºC)
NEC
Maximum motor surface
temperature (C)
T1
450
T2
T2
T2A
12B
T2C
T2D
300
280
260
230
215
T3
T3
T3A
T3B
T3C
200
180
165
160
T4
135
120
T5
T4
T4A
T5
T6
T6
EN / IEC
60079-0
T1
100
85
VSD SAMPLE SOLUTION

Solution for “Ex nA” y “Ex tD/DIP” (T3, T4, T5, T6 < 200ºC) y “Ex d, de y p” en Zone 2
o ATEX (PT100 or PTC) temperature relay that can be either connected to the drive’s STO or the
upstream disconnector.
o Appropiate motor sizing(motor derating)
o Switching frequency >3kHz
o Declaration of conformity. Power Electronics assumes the responsibility.

Solutions for Ex d y Ex p motors (Zone 1) :
o The intrinsic construction of the motors reduce all the risk except the overheating of the motor
housing
o That risk can be eliminated by installing:
o ATEX (PT100 o PTC) relay connected to the drive’s input safe stop STO (SD700 only).
o ATEX (PT100 o PTC) relay connected to the upstream disconnector.
o Appropiate motor sizing(motor derating)
o Switching frequency >3kHz

The installation of an “Ex e” motor in Zone 1 or 2 is not feasible.

SD700 offers unique features that reduces associated hazard effects in ATEX Zones:
o It integrates built-in as standard a dV/dt filter and a CLAMP system that reduce dV/dt rise time to
(500V/µs -800V/µs)
o Reduce Peak Voltages at the Motor Winding
o Reduce CMC and bearing currents that reduce the risk of winding sparks.
o Works at a switching frequency over 4kHz that reduce motor overheating
o Built-in and adjustable motor thermal model.
DERATING CURVE FOR ABB MOTORS
nA motors derating
PWM converters fs>3kHz
tD/DIP motors derating
PWM converters fs>3kHz
SS DESCRIPTION

Power Electronics’ soft starters V2, V5 y VS65 do not
produce any abnormal electric performance that the Direct On
Line Start shall cause under normal conditions. Except if the
starting sequence takes too long or the number of starts are
above the one that the motor manufacturer determines.

Solution for Ex nA y Ex tD/DIP motors ( Zone 2):
o Declaration of conformity including a limitation
considering number of starts per hour and maximum
starting time. Power Electronics assumes the
responsibility.

Solution for Ex d y Ex p (Zone 1) :
o The intrinsic construction of the motors reduce all the risk
except the overheating of the motor housing
o That risk can be eliminated by installing:
o ATEX (PT100 o PTC) relay activating the line
contactor (VS65)
o ATEX (PT100 o PTC) relay connected to the
upstream disconnector.

The installation of an “Ex e” motor in Zone 1 or 2 is
not feasible.
POWER ELECTRONICS
appreciate your attention
More info:
www.power-electronics.com