Wilo Rexa CUT, Installation And Operating Instructions Manual, Page: 56 / 384

56 WILO SE 11-2014 V05 DIN A4
English APPENDIX
10.3.1. Identification of Ex-rated pumps
Pumps that have been approved for use in an
explosive atmosphere are be marked as follows on
the rating plate:
• “Ex” symbol of the corresponding approval
• Information on Ex classification
• Certification number
10.3.2. ATEX approval
The motors are certified for use in potentially
explosive areas in accordance with EC direc -
tive 94/09/EC, which requires device group II,
category 2.
The motors can be used in both zone 1 and zone
2.
These motors may not be used in zone 0!
Non-electrical devices (e.g. hydraulics) also com -
ply with EC directive 94/09/EC.
ATEX classification
The Ex classification, for example,
II 2G Ex de IIB T4 Gb on the rating plate indicates
the following:
• II = device group
• 2G = device category (2 = suitable for zone 1, G =
gas, vapour and mist)
• Ex = explosion-protected device complying to
Euro norm
• d = ignition protection type for motor casing:
Pressure-resistant encapsulation
• e = ignition protection for terminals: Increased
safety
• II = intended for places where explosions may
occur, with the exception of mines
• B = intended for use with gases in sub-group B
(all gases excluding hydrogen, acetylene, carbon
disulphide)
• T4 = max. surface temperature of the device is
135 °C
• Gb = device protection level “b”
“Pressure-resistant encapsulation” protection
class
Motors in this protection type must be equipped
with a temperature limit (1-circuit temperature
monitoring).
Non-immersed operation
The motor must be immersed in an explosive
atmosphere!
Certification number
The certification number of the approval is locat -
ed on the rating plate, in your order confirmation
as well as on the technical data sheet.
10.3.3. Electrical connection
ELECTROCUTION hazard!
Incorrect electrical connections can cause
fatal electric shocks and/or explosion. Elec-
trical connections may only be carried out by
a qualified electrician approved by the local
energy supply company, in accordance with
locally applicable regulations.
In addition to the information in the “Electrical
connection” section, the following points must be
observed for Ex-rated pumps:
• The power supply cable must be connected
outside the potentially explosive area, or inside a
housing with ignition protection conforming to
DIN EN 60079-0!
• Voltage tolerance: ±10 %
Units with a rated voltage of 380...415 V have a
voltage tolerance of max. ± 5 % .
• All monitoring devices outside the “spark-proof
areas” must be connected via an ex-rated cut-off
relay.
Temperature monitoring device connection
The motor is equipped with a temperature limit
(1-circuit temperature monitoring).
The motor can be optionally equipped with a
temperature control and limit function (2-circuit
temperature monitoring).
RISK of fatal injury due to incorrect connec-
tion!
Risk of explosion due to overheating of the
motor! The temperature monitoring device
must be connected in such a way that, when
triggered, it can only be restarted after the
“release button” has been activated manually!
In 2-circuit temperature monitoring, automatic
restarting can be implemented via the tempera-
ture control. The maximum switching frequency
(15/h with a 3-minute pause) must be observed.
• Bimetallic strips must be connected via an eval-
uation relay. We recommend the “CM-MSS” relay
for this. The threshold is already pre-set.
Connection values: max. 250 V(AC), 2.5 A,
cos φ = 1
• PTC sensors (optionally available and in accord -
ance with DIN 44082) must be connected via an
evaluation relay. We recommend the “CM-MSS”
relay for this. The threshold is already pre-set.
When the threshold is reached, the pump must
switch off.
Motor compartment monitor
• The motor compartment monitor must be con -
nected via an evaluation relay. We recommend
the “NIV 101/A” relay for this. The threshold is
30 kOhm. When the threshold is reached, the
pump must switch off.