3RB30 and 3RB31 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
3RB30 and 3RB31 devices are not designed for use in hazardous areas.
When used in potentially explosive areas, 3RB30 and 3RB31 devices
must be adapted according to the respective ignition protection type.
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 3RB30 and 3RB31 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).
PTB 09 ATEX 3001
WARNING
!
All connection, commissioning 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
3ZX1012-0RB30-1AA1 (S00/S0)
3ZX1012-0RB30-3AA1 (S2)
3ZX1012-0RA21-1AC0
2.1 Setting the rated motor current
Set the 3RB30 / 3RB31 to the rated current of the motor (according to
the name plate or the type approval certificate of the motor).
3ZX1012-0RB30-1CA1
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 3RB30 / 3RB31. Select the trip class so that the motor is
thermally 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
CLASS 30E
20E
T
= 18 s
E
10E
CLASS 5E
I
/ I
A
N
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 combinations with other contactors, please observe the
respective 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
– CLASS 20 and CLASS 30 – in particular.
2.4 RESET
CAUTION
!
When the 3RB30 / 3RB31 is in "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 additional ON
button - as shown in the operating instructions - is necessary to
prevent the motor from automatically starting up again after being
tripped. If the 3RB30 / 3RB31 is used without a separate thermistor
protection when the overload protection trips, the motor must only
be connected by a specialist.
The "Automatic RESET" mode must not be used in applications in
which an unexpected motor restart could lead to personal injury or
damage to property.
3RB30 / 3RB31
English
time = 18 s, I
/ I
= 5.0
E
A
N
Tripping conditions of the
EEx motor,
selected: CLASS 10E
= 5.0
3