Ex Approval - Wilo -Rexa PRO series Einbau- Und Betriebsanleitung

APPENDIX
turer if necessary). Increased motor noise caused by
the harmonics of the power supply is normal.
When configuring the variable frequency drive,
always make sure the quadratic curve (V/F curve) for
pumps and fans is correctly set! This ensures that
the output voltage at frequencies greater than the
rated frequency (50 Hz or 60 Hz) is adjusted to the
power requirement of the pump. Newer variable fre-
quency drives feature an automatic power optimi-
zation function which achieves the same effect. To
set the variable frequency drive, please refer to its
installation and operating instructions.
Faults in motor monitoring may occur on motors fed
by a variable frequency drive depending on the type
of variable frequency drive used and the installation
conditions present. The following general measures
could help to reduce or avoid faults:
• Keep within the thresholds stated in IEC 60034-17
for the voltage peaks and rise rate (output filters
may be necessary).
• Vary the pulse frequency of the variable frequency
drive.
• In the case of faults with the sealing chamber moni-
tor, use our external double rod electrode.
The following construction measures could also
help to reduce or prevent faults:
• Use shielded power supply cables.
Summary
• Continuous operation between 1 Hz and the rated
frequency (50 Hz or 60 Hz), while observing the min.
flow rate
• Consider additional measures with regard to EMC
(choice of variable frequency drive, using filters,
etc.).
• Never exceed the rated current or rated speed of
the motor.
• It must be possible to connect the motor's own
temperature monitor (bimetallic strip or PTC sen-
sor).

10.2. Ex approval

This section contains special information for owners
and operators of pumps which have been built and
certified for use in environments where explosions
may occur.
It expands on and therefore supplements the stan-
dard instructions for this pump. It also expands on
and supplements the "general safety information"
section and must be read and fully understood by all
users and operators of the pump.
This section applies only to Ex-rated pumps and
contains additional instructions for these pumps!
10.2.1. Identification of Ex-rated pumps
Pumps that have been approved for use in an explo-
sive atmosphere are marked as follows on the rating
plate:
• "Ex" symbol for the relevant approval
• Information on Ex classification
Installation and operating instructions Wilo-Rexa PRO
10.2.2. FM approval
The motors are certified and approved by the
recognized testing and licensing authority "FM
Approvals" according to standards FM 3600, 3615,
3615.80, and ANSI/UL-1004. The motors are ap-
proved for operation in potentially explosive areas
that require electrical devices with the protection
class "Explosionproof, Class 1, Division 1."
Operation is therefore also possible in areas with the
required protection class "Explosionproof, Class 1,
Division 2" according to the FM standards.
10.2.3. FM classification
Example of Ex marking:
CLASS I, DIV. 1, GROUPS C, D
CLASS II, DIV. 1, GROUPS E, F, G
CLASS III
TEMPERATURE CODE T3C
Meaning:
• Class 1=gases, fumes, mist
Division 1 = explosive atmosphere constantly or
occasionally present under normal conditions
Groups C, D = gas groups: ethylene (C), propane (D)
• Class 2=dust
Division 1 = explosive atmosphere constantly or
occasionally present under normal conditions
Groups E, F, G = dust groups: metal (E), carbon (F),
grain (G)
• Class 3=fibers and lint
• T3C=max. surface temperature of the pump 320 °F
(160 °C)
The specifications for the max. immersion depth
and the max. temperature of the fluid are likewise
noted on the rating plate.
"Explosion proof" protection class
Motors in this protection class must be equipped
with a temperature limiter.
Non-immersed operation
The motor must always be immersed during oper-
ation!
10.2.4. Electrical connection
ELECTROCUTION hazard!
Incorrect electrical connections can cause fatal
electric shocks and/or explosion. Electrical con-
nections 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 an approved level of ignition protection.
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