Operation With Frequency Converters; Ex-Approval - Wilo EMU FA+T Einbau- Und Betriebsanleitung

APPENDIX
Geomet-coated screws (strength 10.9) with Nord-Lock
washer
Thread
Nm
126.5
M12
155
M16
265
M20

10.2. Operation with frequency converters

Any standard motor conforming to IEC 60034-17
can be used. If the rated voltage is above
415 V/50 Hz or 480 V/60 Hz, you must consult
the manufacturer. Because of the additional
heating caused by harmonics, the rated power of
the motor should be around 10% more than the
power requirement of the pump. For frequency
converters with a low-harmonic output, it may be
possible to reduce the 10% power reserve. This
is normally done by using output filters. Further-
more, the standard motors are not equipped
with shielded cables. The frequency converter
and filter must be synchronized with each other.
Ask the manufacturer.
The configuration of the frequency converter de-
pends on the rated motor current. Make sure that
the pump operates without jerking or vibrating,
especially in the lower speed range. Otherwise,
the mechanical shaft seals could be damaged and
start leaking. You must also consider the flow rate
in the pipe. The slower the flow rate, the greater
the risk of solids depositing in the pump and pip-
ing. We recommend complying with a minimum
flow rate of 0.7 m/s at a pumping pressure of
0.4 bar.
It is important that the pump operates across
the entire control range without vibrations,
resonance, oscillation or excessive noise (ask the
manufacturer if necessary). Increased motor noise
caused by the harmonics of the power supply is
normal.
When configuring the frequency converter,
always make sure the quadratic curve (U/F pump
curve) for pumps and fans is correctly set! This
ensures that the output voltage at frequencies
less than the rated frequency (50 Hz or 60 Hz) is
adjusted to the power requirement of the pump.
Newer frequency converters feature an automatic
power optimization function which achieves the
same effect. For the frequency converter set-
ting, please refer to its installation and operating
instructions.
Faults with the motor monitor may occur on mo-
tors fed by a frequency converter depending on
the type used and installation conditions present.
The following general measures could help to
reduce or avoid faults:
• Keeping within the thresholds stated in
IEC 60034-17 for the voltage peaks and rise
speed (output filters may be necessary).
• Varying the pulse frequency of the frequency
converter.
Installation and operating instructions Wilo-EMU FA + T-Motor
Tightening torque
kp m
12.90
15.84
27.08
• Using our external double pencil electrode for
faults with the sealing chamber monitor.
The following construction measures could also
help to reduce or prevent faults:
• Separate power supply cables for the main and
control cable (depending on the motor size).
• Adequate clearance between the main and con-
trol cable.
• Using shielded power cables.
Summary
• Continuous operation up to rated frequency
(50 Hz or 60 Hz), observing the min. flow rate
• Consider additional measures with regard to EMC
(choice of frequency converter, 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).

10.3. 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
standard instructions for these pumps. 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!
10.3.1. 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)
English
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