Siemens 3RB20 Manual page 3

3RB20 and 3RB21 Motor protection devices
for potentially explosive areas
Safety and commissioning instructions
DANGER
!
Hazardous voltage.
Will cause death or serious injury.
Turn off power before working on this equipment.
CAUTION
Reliable functioning of the equipment is only ensured with
certified components.
1. General
Notes and standards
Due to the heightened risk in potentially explosive areas, the following
notes and standards have to be observed carefully:
• EN 60079-14 / VDE 0165-1 Electrical apparatus for explosive gas
atmospheres.
• EN 60079-17 Inspection and maintenance of electrical installations in
hazardous areas.
• EN 50495 Safety devices required for the safe functioning of
equipment with respect to explosion risks.
All 3RB20 and 3RB 21 electronic overload relays are authorized under
Device Group II, Category (2) for area "G" (areas in which explosive
gas, steam, fog and air mixtures are present) and additionally for area
"D" (areas with combustible dust). 3RB20 and 3RB21 devices are not
designed for use in hazardous areas. When used in potentially explo-
sive areas, 3RB20 and 3RB21 devices must be adapted according to
the respective ignition protection type.
PTB 06 ATEX 3001
WARNING
!
All connection, installation and maintenance work must be carried
out by qualified, responsible specialists. Improper behavior can
lead to severe personal injury or property damage.
2. Installation and Commissioning
NOTICE
Please observe the operating instructions (supplied with the
device)
• 3RB201 to 3RB204 and 3RB211 to 3RB214
(3ZX1012-0RB20-1AA1)
• 3RB205 / 3RB206 / 3RB215 / 3RB216
(3ZX1012-0RB20-1BA1).
2.1 Setting the motor rated current
Set the 3RB20 / 3RB21 to the rated current of the motor (according to
the name plate or the type approval certificate of the motor).
3ZX1012-0RB20-1CA1
II (2) G [Ex e] [Ex d] [Ex px]
II (2) D [Ex t] [Ex p]
CAUTION
Observe the trip class and the tripping characteristics of the
3RB20 / 3RB21. Select the trip class so that the motor is thermi-
cally protected even when the rotor stalls.
The motor, the lines and the contactors must be designed for the
selected trip class.
Example: Motor 500 V, 50 / 60 Hz, 110 kW, 156 A, temperature class
T3, T -time = 18 s, I / I = 5.0
E A N
T =18s
E
I
A
2.2 Short-circuit protection according to EN 60947-4-1 for type of
coordination "2"
The short-circuit protection must be adopted from the separate
overcurrent protection devices.
NOTICE
In combination with other contactors please observe the respec-
tive maximum contactor protection for type of coordination "2".
2.3 Cable protection
NOTICE
Excessive surface temperatures of the cables and lines must be
prevented by dimensioning the cross sections accordingly.
An adequate cable cross section must be chosen for heavy
starting - CLASS20 and CLASS30 - in particular.
2.4 RESET
CAUTION
!
When the 3RB20 / 3RB21 is in the "Automatic RESET" mode, the
reset is carried out automatically at the end of the cooling time
without the RESET button being pressed. In this case, an addi-
tional ON button is necessary - as described in the operating
instructions - to prevent the motor from automatically starting up
again after being tripped. If the 3RB20 / 21 is used without a
separate thermistor protection when the overload release trips,
the motor can only be connected by a specialist.
The "Automatic RESET" mode may not be used in applications in
which an unexpected motor restart could lead to personal injury or
damage to property.
3RB20 / 3RB21
EN 1088 (5.7)
English
Tipping conditions of the
EEx motor
selected: CLASS 10E
/ I =5,0
N
3